Apple

An illustrated version of this guideline is available online at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

Publication 3432 University of California Agriculture and Natural Resources UC Statewide Integrated Pest Management Program

UC IPM Pest Management Guidelines: APPLE

January 2011 Contents (Dates in parenthesis indicate when each topic was updated)

General Information Major Monitoring Periods in an IPM Program (8/06) ....................................................................................................................... 1 Relative Toxicities of Insecticides and Miticides Used in Apples to Natural Enemies and Honey Bees (1/11) .............................. 2 General Properties of Fungicides Used in Apples (3/09) .................................................................................................................. 4 Most Effective Treatment Timings for Key Diseases (3/09) ............................................................................................................. 5

Insects and Mites (section reviewed 8/06) Apple Maggot (3/09) ......................................................................................................................................................................... 6 Apple Pandemis (3/09) ...................................................................................................................................................................... 8 Codling Moth (12/09) ...................................................................................................................................................................... 11 Cribrate Weevil (8/06) ..................................................................................................................................................................... 17 European Red Mite (3/09) ............................................................................................................................................................... 18 Eyespotted Bud Moth (3/09) ............................................................................................................................................................ 21 Fruittree Leafroller (3/09) ................................................................................................................................................................ 22 Green Apple Aphid (1/11) ............................................................................................................................................................... 24 Green Fruitworms (3/09) ................................................................................................................................................................. 26 Italian Pear Scale (3/09) ................................................................................................................................................................... 28 Leafhoppers (3/09) ........................................................................................................................................................................... 29 Leafminers (3/09) ............................................................................................................................................................................ 31 Lygus Bugs (3/09) ........................................................................................................................................................................... 34 Obliquebanded Leafroller (3/09) ..................................................................................................................................................... 36 Omnivorous Leafroller (3/09) .......................................................................................................................................................... 38 Orange Tortrix (3/09) ....................................................................................................................................................................... 40 Pacific Flatheaded Borer (3/09) ....................................................................................................................................................... 42 Rosy Apple Aphid (1/11) ................................................................................................................................................................. 43 San Jose Scale (3/09) ....................................................................................................................................................................... 46 Stink Bugs (3/09) ............................................................................................................................................................................. 48 Webspinning Spider Mites (3/09) .................................................................................................................................................... 50 Western Flower Thrips (12/09) ........................................................................................................................................................ 52 Western Tussock Moth (3/09) ......................................................................................................................................................... 53 Woolly Apple Aphid (1/11) ............................................................................................................................................................. 54

Diseases (section reviewed 8/06) Apple Scab (3/09) ......................................................................................................................................................................... 56 Armillaria Root Rot (Oak Root Fungus) (3/09) ........................................................................................................................ 60 Bacterial Blossom Blast (3/09) .................................................................................................................................................... 61 European Canker (3/09) .............................................................................................................................................................. 62 Fire Blight (3/09) ........................................................................................................................................................................... 63 Phytophthora Root and Crown Rot (3/09) ............................................................................................................................... 65 Powdery Mildew (3/09) .............................................................................................................................................................. 66

Nematodes (3/09) ................................................................................................................................................................................ 68

Apple Thinning Sprays (8/06) ........................................................................................................................................................... 70

Precautions for Using Pesticides ........................................................................................................................................................ 72

UC IPM Pest Management Guidelines – APPLE

ii

Authors Insects and Mites: J. L. Caprile, UCCE Contra Costa Co.; L. R. Wunderlich, UCCE El Dorado Co.; P. M. Vossen,

UCCE Sonoma/Marin counties; W. W. Coates, UCCE San Benito Co.; H. L. Andris, UCCE Fresno Co.; L. G. Varela, UC IPM Program, Sonoma Co.; W. J. Bentley, UC IPM Program, Kearney Agricultural Center, Parlier

Diseases: W. D. Gubler, Plant Pathology, UC Davis Nematodes: B. B. Westerdahl, Nematology, UC Davis Apple Thinning Sprays: J. A. Grant, UCCE San Joaquin Co.; R. S. Johnson, Kearney Agricultural Center, Parlier;

P. M. Vossen, UCCE Sonoma/Marin counties Acknowledgment for contributions to Insects and Mites: C. Pickel, UC IPM Program, Sutter/Yuba counties Acknowledgment for contributions to Diseases: B. L. Teviotdale, Kearney Agricultural Center, Parlier Acknowledgment for contributions to Nematodes: U. C. Kodira, Plant Pathology, UC Davis

About this publication Produced and edited by: UC Statewide IPM Program University of California, Davis Guidelines Coordinator: T. A. Martin Production: M. J. O'Neill

This publication has been anonymously peer reviewed for technical accuracy by University of California scientists and other qualified professionals. This review process was managed by the ANR Associate Editor for Agricultural Pest Management.

The UC IPM Pest Management Guidelines are available from: • Online: http://www.ipm.ucdavis.edu • UC Cooperative Extension County Offices • University of California

ANR/Communication Services 6701 San Pablo Avenue, 2nd Floor Oakland, CA 94608-1239 510-642-2431; 800-994-8849

Updates: These guidelines are updated regularly. Check with your University of California Cooperative Extension Office or the UC IPM World Wide Web site for information on updates. Note to readers: These guidelines represent the best information currently available to the authors and are intended to help you in making the best choices for an IPM program. Not all formulations or registered materials are mentioned. Always check the label and with local authorities for the most up-to-date information regarding registration and restrictions on pesticide use. Check with your agricultural commissioner for latest restricted entry intervals.

To be used with UC ANR Publication 3340 Integrated Pest Management for Apples and Pears, 2nd edition


Major Monitoring Periods in an IPM Program (8/06) 1 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

General Information MAJOR MONITORING PERIODS IN AN IPM PROGRAM (8/06) Monitoring is a crucial component of all IPM Programs. It helps you identify potential problems and to assess the overall condition of the orchard. Check the orchard regularly for pests and natural enemies of pest species, as well as the maturity and health of the crop. There are six major monitoring periods in an apple orchard. The presence and population development of key pests are tracked during these periods. The information below outlines the monitoring periods, major pests monitored, and the methods used to monitor them. Detailed information on each pest and its monitoring method is available under the individual pest sections in this guideline. WINTER (Dormant)

• Look for mite eggs, rosy apple and green apple aphid eggs, San Jose scale SPRING (March, April, May)

Prebloom (Green tip to pink bud) • Examine shoots for rosy apple and green apple aphids and caterpillars (apple pandemis, fruittree

leafroller, green fruitworms, obliquebanded leafroller, omnivorous leafroller, orange tortrix) • Monitor weather for conditions favorable to scab, powdery mildew, bacterial blast Bloom (First bloom to petal fall) • Monitor weather for conditions favorable to scab, fireblight, bacterial blast, powdery

mildew • Set out and monitor codling moth traps by mid-March • In mating disruption orchards, put pheromone dispensers out • Continue to examine shoots and bloom for aphids and caterpillars (apple pandemis, fruittree

leafroller, green fruitworms, obliquebanded leafroller, omnivorous leafroller, orange tortrix) Postbloom • Continue monitoring weather for conditions favorable to scab, fire blight, powdery

mildew • Continue monitoring codling moth trap and check fruit • Continue to examine shoots and leaves for rosy apple and green apple aphids, leafhopper

nymphs, leafrolling caterpillars (apple pandemis, fruittree leafroller, green fruitworms, oblique-banded leafroller, omnivorous leafroller, orange tortrix), tentiform leafminer and parasitism (April and May), and San Jose scale crawlers (May)

• Monitor weeds for stink bugs and fruit for lygus bug damage SUMMER (June, July, August)

• Continue monitoring codling moth traps and check fruit • In mating disruption orchards, apply a second application of pheromone when first

expires • Examine fruit for orange tortrix (June-July), pandemis (June-July), obliquebanded leafroller (July–

August), eyespotted bud moth (June-July), and stink bug/lygus damage • Examine leaves for mites, tentiform leafminer (June), leafhoppers

FALL (September, October, November)

Preharvest • Continue monitoring codling moth traps and check fruit • Examine fruit for lygus/stink bug damage • Examine leaves for mites and leafhoppers


Relative Toxicities of Insecticides and Miticides Used in Apples to Natural Enemies and Honey Bees (1/11) 2 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

RELATIVE TOXICITIES OF INSECTICIDES AND MITICIDES USED IN APPLES TO NATURAL ENEMIES AND HONEY BEES (1/11)

Common name (trade name)

Mode of action1

Selectivity2 (affected groups)

Predatory mites3

General predators4 Parasites4

Honey bees5

Duration of impact to natural enemies6

abamectin (Agri-Mek EC) 6 moderate (mites, leafminers)

H L M/H I7 moderate to predatory mites and affected insects

acetamiprid (Assail) 4A moderate (sucking insects, larvae)

—8 —9 — III moderate

azadirachtin (Neemix) 18B broad (insects, mites) — L/M L/M III short

azinphosmethyl (Guthion WP) 1B broad (insects, mites) L/M H H I long

Bacillus thuringiensis ssp. kurstaki 11.B2 narrow (caterpillars) L L L IV short

bifenazate (Acramite) 25 narrow (spider mites) L L L III short

carbaryl (Sevin XLR Plus) 1A broad (insects, mites) L H H I10 long

chlorantraniliprole (Altacor) 28 — — — — — —

chlorpyrifos (Lorsban EC) 1B broad (insects, mites) M H H I11 moderate

clofentezine (Apollo) 10A narrow (mites) M L L IV short

Cydia pomenella granulovirus (Cyd-X) — narrow (codling moth) none none none IV none

cypermethrin (Ammo) 3 broad (insects, mites) H H H I12 moderate

diazinon (WP, EC) 1B broad (insects, mites) L H H I moderate to long

dimethoate 1B broad (insects, mites) H H H I long

disulfoton (Di-Syston EC) 1B broad (insect, mites) H H H II13 —

endosulfan (Thionex) 2A broad (insects, mites) L M M II13 moderate

esfenvalerate (Asana) 3 broad (insect, mites) H M H I7 moderate

etoxazole (Zeal) 10C narrow (mites) H9 L — IV short

fenbutatin oxide (Vendex) 12B narrow (pest mites) L L L IV short

fenpropathrin (Danitol) 3 broad (insects, mites) H H H I —

fenpyroximate (Fujimate) 21 narrow (mites and some insects)

H L L IV short

formetanate hydrochloride (Carzol) 1A broad (insects, mites) M/H H H II13 long, unless washed off

hexythiazox (Savey) 10B narrow (mites) M L L IV short to moderate

imidacloprid (Provado) 4A narrow (sucking insects)

— — H II short to moderate

indoxacarb (Avaunt) 22 narrow (caterpillars) — L L III moderate

insecticidal soap (M-Pede) — broad (insects, mites) M M M IV short

kaolin clay (Surround) — broad (insects, mites) M M — IV long

lambda-cyhalothrin (Warrior) 3 broad (plant bugs, beetles, caterpillars)

H H H I14 moderate

methidathion (Supracide) 1B broad (insects, mites) H H H I moderate to long

methoxyfenozide (Intrepid) 18A narrow (caterpillars) L L L IV short

neem oil (Trilogy) — broad (soft-bodied) insects)

L L L III short

oxamyl (Vydate) 1A broad (insects, mites) H H H II13 moderate

permethrin (Ambush, Pounce) 3 broad (insects, mites) L H H I long

petroleum oil — broad (exposed insects, mites)

L15 L L III short

phosmet (Imidan) 1B broad (insects, mites) H H H I moderate to long

pyridaben (Nexter) 21 broad (insect, mites) M/H M — III short


Relative Toxicities of Insecticides and Miticides Used in Apples to Natural Enemies and Honey Bees (1/11) 3 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

Common name (trade name) Mode

of action1 Selectivity2 (affected groups)

Predatory mites3

General predators4 Parasites4

Honey bees5

Duration of impact to natural enemies6

pyriproxyfen (Esteem, Seize) 7C narrow (scale, beetles) L H16 L IV long

spinetoram (Delegate) 5 narrow (caterpillars, aphids, scales, leafminers)

L/H M17 L/M III moderate18

spinosad (Entrust, Success) 5 narrow (caterpillars, aphids, scales, leafminers)

L/H M17 L/M III short to moderate17

spirotetramat (Movento) 23 narrow (aphids) L L L — short

sulfur — narrow (mites) L/H M/L H IV short

thiacloprid (Calypso) 4A moderate (sucking insects, larvae)

—8 — — III —

H = high M = moderate L = low — = no information

1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action Group number more than twice per season to help prevent development of resistance. For example, the organophosphates have a Group number of 1B; chemicals with a 1B Group number should be alternated with chemicals that have a Group number other than 1B. Mode of action Group numbers are assigned by IRAC (Insecticide Resistance Action Committee). For additional information, see their Web site at http://www.irac-online.org/.

2 Selectivity: Broad means it affects most groups of insects and mites; narrow means it affects only a few specific groups. 3 Generally, toxicites are to western predatory mite, Galendromus occidentalis. Where differences have been measured in toxicity of the pesticide resistant strain versus the native

strain, these are listed as pesticide-resistant strain/native strain. 4 Toxicities are averages of reported effects and should be used only as a general guide. Actual toxicity of a specific chemical depends on the species of predator or parasite,

environmental conditions, and application rate. 5 Ratings are as follows: I-Do not apply to blooming plants; II-Apply only during late evening; III-Apply only during late evening, night, or early morning; and IV-Apply at any time with

reasonable safety to bees. For more information, see How to Reduce Bee Poisoning From Pesticides, Pacific Northwest Extension Publication PNW591. 6 Duration: Short means hours to days; moderate means days to 2 weeks; and long means many weeks or months. 7 If rate is 0.025 lb a.i./acre, rating is II. 8 May cause flare-ups of spider mite populations. 9 Does not kill adults but sterilizes females. 10 If rate is 1.5 lb a.i. or less and dilution not greater than 1:19, rating is II. 11 If rate is 0.05 lb a.i./acre or less, rating is III. 12 If rate is 0.025 lb a.i./acre or less, rating is III. 13 If rate is 0.5 lb a.i./acre or less, rating is III. 14 If rate is 0.02 lb a.i./acre, rating is II. 15 Rating depends on rate used. 16 Kills lady beetles. 17 Toxic against some natural enemies (predatory thrips, syrphid fly and lacewing larvae, beetles) when sprayed and up to 5-7 days after, especially for syrphid fly larvae. 18 Residual is moderate if solution is between pH of 7 to 8.

Acknowledgements: This table was compiled based on research data and experience of University of California scientists who work on a variety of crops and contribute to the Pest Management Guideline database, and from Flint, M. L. and S. H. Dreistadt. 1998. Natural Enemies Handbook: An Illustrated Guide to Biological Pest Control, ANR Publication 3386.


General Properties of Fungicides Used in Apples (3/09) 4 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

GENERAL PROPERTIES OF FUNGICIDES USED IN APPLES (3/09)

Common name (trade name) Chemical class Activity

Mode of action (FRAC number)1

Resistance potential Comments

bordeaux inorganic contact multi-site (M1) low

captan phthalamide contact multi-site (M3) low highly toxic to honey bee larvae

copper inorganic contact multi-site (M1) low

cyprodinil (Vangard) anilinopyrimidine contact single-site (9) high

fenarimol (Rubigan) DMI2-triazole systemic (local) single-site (3) high

kresoxim-methyl (Sovran) strobilurin contact and systemic (local)

single-site (11) high

mancozeb (Dithane) carbamate EBDC3 contact multi-site (M2) very low

mefenoxam (Ridomil Gold) acylalanine systemic single-site (4) high

myclobutanil (Rally) DMI2-triazole systemic (local) single-site (3) high

pyrimethanil (Scala) anilinopyrimidine mostly contact single-site (9) high

sulfur inorganic contact multi-site (M2) low highly toxic to native strains of western predatory mite (Galendromus occidentalis) and to parasites

thiophanate-methyl (Topsin-M) benzimidazole systemic (local) single-site (1) very high

triadimefon (Bayleton) DMI2-triazole systemic (local) single-site (3) high

trifloxystrobin (Flint) stroblilurin contact and systemic

single-site (11) high

triflumizole (Procure) DMI2-imidazole systemic (local) single-site (3) high

ziram carbamate (DMDC) 4

contact multi-site (M2) low

1 Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of actions (for more information, see

http://www.frac.info/). Fungicides with a different group number are suitable to alternate in a resistance management program. In California, make no more than one application of fungicides with mode of action Group numbers 1, 4, 9, 11, or 17 before rotating to a fungicide with a different mode of action Group number; for fungicides with other Group numbers, make no more than two consecutive applications before rotating to fungicide with a different mode of action Group number.

2 DMI = demethylation (sterol) inhibitor 3 EBDC = ethylene bisdithiocarbamate 4 DMDC = dimethyl dithiocarbamate

Acknowledgment: Adaskaveg et al., 2011. Efficacy and Timing of Fungicides, Bactericides, and Biologicals for Deciduous Tree Fruit, Nut, Strawberry, and Vine Crops(932 KB, PDF).


Most Effective Treatment Timings for Key Diseases (3/09) 5 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

MOST EFFECTIVE TREATMENT TIMINGS FOR KEY DISEASES (3/09) Note: Not all indicated timings may be necessary for disease control.

Disease Fall Delayed dormant Green tip Pink bud Spring

Scab1 ++2 ++2 +++ +++ +++

Powdery mildew3 — — — +++ +++

Fire blight — — — +++ +++4

Rating: +++ = most effective, ++ = moderately effective, — = ineffective

1 Protection of early tissue is important. Additional applications should be made according to infection periods as determined by the Mills table.

2 Disruption of pseudothecial development (fall) and inactivation of overwintering twig lesions (delayed dormant) occurs; effects of these treatments on disease control uncertain.

3 Early application is most effective; added treatments are needed if mildew continues. 4 Start management program at the beginning of bloom and continue until the end of bloom. Several models (Maryblyt, Cougar Blight, etc.)

are available for forecasting infection periods and treatment timing. Acknowledgment: Adaskaveg et al., 2011. Efficacy and Timing of Fungicides, Bactericides, and Biologicals for Deciduous Tree Fruit, Nut, Strawberry, and Vine Crops(932 KB, PDF).


Apple Maggot (3/09) 6 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

Insects and Mites APPLE MAGGOT (3/09) Scientific Name: Rhagoletis pomonella DESCRIPTION OF THE PEST Apple maggot is a native pest of the eastern United States and Canada. In 1979 it was discovered in Oregon and has since moved into California, Washington, and other Western states. Hawthorn and apples are favored host plants, but cherries, pears, and other fruits have been attacked. Adult flies are somewhat smaller than houseflies and have clear wings with characteristic black bands, a pronounced white spot on the back of the thorax, and a black abdomen with light-colored crossbands. Female flies have four crossbands on the abdomen, and males have three. The apple maggot is closely related to the walnut husk fly and cherry fruit fly. It can be distinguished from these other pests by the banding on its wings. However, it is difficult to distinguish apple maggot from snowberry maggot, a close look-alike that occurs throughout California but that does not attack apples and pears. Larvae are cream-colored maggots with a blunt posterior and a tapered front end that contains two black mouth hooks. DAMAGE Female apple maggot adults deposit eggs singly under the apple skin. Damage is caused when larvae burrow and feed on apple flesh. Browning of the trails occurs as the apple responds to this injury and bacteria associated with maggots cause fruits to rot internally. MANAGEMENT In areas where apple maggot is established, the pest is managed with sprays of organophosphate insecti-cides targeted to the first emerging adult flies. Not all orchards require treatment. Use sticky traps for detection and treatment timing. If apple maggots are found in counties where it is not yet established, notify the county agricultural commissioner. Biological Control Because the apple maggot feeds within fruit, biological control agents have not been very effective. Organically Acceptable Methods Baited sprays such as GF-120 are organically acceptable. Mass trapping with dark-colored, plastic sticky spheres (placed 1–2 per tree) has been used by organic growers in the eastern U.S. to greatly reduce damage. Replace traps when sticky material is no longer effective. Monitoring and Treatment Decisions Emergence and dispersal of adult flies must be carefully monitored to effectively time treatments. Sticky traps, including yellow rectangles and red spheres, are both used in other areas to monitor adults and time treatments. Unfortunately, only provisional economic thresholds are available for apple maggots, even in areas where it has long been a pest. You can detect the first emergence of adults by hanging yellow sticky traps in abandoned orchards or unsprayed apple trees in infested areas. To detect the beginning of egg laying, hang red sticky spheres in apple trees, then treat as soon as the first fly is found. In Oregon, where some orchards are now being treated regularly for apple maggots, the first maggot spray is applied 7 to 10 days after the first fly has emerged. Later sprays follow at 10- to 14-day intervals as long as adults are active and are being caught in traps.


Apple Maggot (3/09) 7 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html


Amount to use** R.E.I.+ (hours)

P.H.I.+ (days) (conc.) (dilute)

When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. A. SPINOSAD (GF-120)# Label rates 4 0 MODE OF ACTION GROUP NUMBER1: 5 COMMENTS: Most effective for small populations B. CORN GLUTEN MEAL (Nu-Lure Insect Bait) 1–3 pt/acre 0 0 . . . PLUS . . . SPINOSAD (Entrust) 2–3 oz 0.5–0.75 oz 4 7 (Success) 6–10 fl oz 2–3.3 fl oz 4 7 MODE OF ACTION GROUP NUMBER1: 5 COMMENTS: Do not apply more than 9 oz/acre/crop of Entrust or 29 fl oz of Success/acre/crop. C. PHOSMET (Imidan) 70WP 4 lb 1 lb 3 days 7 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Apply alone or tank-mixed with Nu-Lure Insect Bait. ** Dilute rate is the rate per 100 gal water; use 400 gal solution/acre. Apply concentrate in 80–100 gal water/acre, or

less if the label allows. + Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated

area can be safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.

* Permit required from county agricultural commissioner for purchase or use. # Acceptable for organically grown produce. 1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-

action Group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a Group number of 1B; chemicals with a 1B Group number should be alternated with chemicals that have a Group number other than 1B. Mode of action Group numbers are assigned by IRAC (Insecticide Resistance Action Committee). For additional information, see their Web site at http://www.irac-online.org/.


Apple Pandemis (3/09) 8 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

APPLE PANDEMIS (3/09) Scientific Name: Pandemis pyrusana DESCRIPTION OF THE PEST Apple pandemis is primarily a pest in Central Coast orchards where it occurs in higher populations in cooler years and in cooler locations. Pandemis overwinters as first instar larvae in apple buds. Larvae become active in spring as the buds open up. Larvae are green caterpillars with a straw- or gold-colored head. Orange tortrix larvae are similar in appearance to apple pandemis but only occur together in the orchard during the month of July. There are two generations a year. DAMAGE Overwintered larvae feed on blooms and on the surface of young fruit, causing them to drop or resulting in scarring and distortion. Summer generation larvae feed on leaf tissue and cause windowpaning. This windowpane can be used to distinguish between apple pandemis and orange tortrix. Windowpaning may also be caused by eyespotted bud moth, however, especially in organic orchards. In addition, when apple pandemis tie leaves to fruit, they cause shallow feeding scars that are also similar to those caused by eyespotted bud moth. MANAGEMENT Control measures aimed against first-generation apple pandemis during bloom and petal fall are general-ly more successful than in-season sprays because summer-generation eggs are laid in rolled leaves and larvae are protected from sprays when they hatch. Biological Control The parasitic wasp Enytus eureka and a tachinid fly in the genus Actia have been found parasitizing apple pandemis larvae; neither is abundant. Organically Acceptable Methods Sprays of Bacillus thuringiensis, the Entrust formulation of spinosad, and kaolin clay are organically acceptable. Monitoring and Treatment Decisions Overwintering larvae can be controlled with a delayed dormant application of oil and insecticide; however, these sprays pose water quality concerns and may pose some risks to raptors, aquatic inverte-brates, beneficials, and other nontarget organisms. If a delayed dormant spray is not applied, sample for apple pandemis between green tip and pink bud; examine 100 fruit clusters per block for larvae. Treat if there are any apple pandemis larvae in the sample. Monitor the summer generations once a month in June, July, and August in conjunction with orange tortrix and eyespotted bud moth: take the first sample no later than mid-June. Examine 10 trees of each variety in each block for 4 minutes each. Each larva found, whether orange tortrix, apple pandemis, or eyespotted bud moth, correlates to about 1% fruit damage at harvest. The threelined leafroller (Pandemis limitata) pheromone trap can be used to monitor apple pandemis. Although this can give you an idea of when moths are flying, it will not provide an accurate assessment of populations in an individual block because traps draw moths in from native vegetation as well as from orchard trees.






When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. DELAYED DORMANT A. NARROW RANGE OIL 4–6 gal 1–1.5 gal 4 0 MODE OF ACTION: Improves translaminar movement and insecticide persistence. . . . PLUS . . . CHLORPYRIFOS* (Lorsban) 4EC Label rates 4 0 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Gives best control. Avoid drift and runoff into surface waters or choose alternative

materials. Chlorpyrifos has been found in surface waters at levels that violate federal and state water quality standards.

TIGHT CLUSTER A. SPINOSAD (Entrust)# 2–3 oz 0.5–0.75 oz 4 7 (Success) 6–10 fl oz 2–3.3 fl oz 4 7 MODE OF ACTION GROUP NUMBER1: 5 COMMENTS: Apply at petal fall when larvae are present. To prevent the development of resistance to

this product, rotate to a material with a different mode of action after treating two consecutive generations. Do not apply more than 3 sprays/season directed at leafrollers. Do not apply more than 9 oz/acre/crop of Entrust or 29 fl oz of Success/acre/crop.

B METHOXYFENOZIDE (Intrepid) 2F 16 fl oz — 4 14 MODE OF ACTION GROUP NUMBER1: 18A COMMENTS: Functions both as an ovicide (when applied to eggs and when eggs are laid on residues)

and as a larvicide (must be ingested for it to be effective). C. CHLORPYRIFOS (Lorsban) 50WP Label rates 4 days 0 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Apply before pink bud and placement of bees in orchards. Do not use postbloom.

Avoid drift and tailwater runoff into surface waters. D. BACILLUS THURINGIENSIS ssp. KURSTAKI# (various products) Label rates — 4 0 MODE OF ACTION GROUP NUMBER1: 11.B2 COMMENTS: Bt is a stomach poison and must be consumed by the leafroller; therefore it is most

effective when applied during warm, dry weather when larvae are actively feeding. Most effective against young larvae. Requires more than 1 treatment; apply second application 7–10 days after first.

E. KAOLIN CLAY# (Surround) 25–50 lb — 4 0 MODE OF ACTION: Unknown. An inorganic insecticide. COMMENTS: Serves primarily as a barrier to oviposition and/or to prevent larvae from entering the

fruit so early application and good coverage are important. Make the first application when larvae are detected and reapply in 7 to 14 days in 100–200 gal water/acre. A total of 3 treatments per generation may be required to keep fruit completely covered during the egg-laying period.

SUMMER A. SPINOSAD (Entrust)# 2–3 oz 0.5–0.75 oz 4 7 (Success) 6–10 fl oz 2–3.3 fl oz 4 7 MODE OF ACTION GROUP NUMBER1: 5 COMMENTS: To prevent the development of resistance to this product, rotate to a material with a

different mode of action after treating two consecutive generations. Do not apply more than 3 sprays/season directed at leafrollers. Do not apply more than 9 oz/acre/crop of Entrust or 29 fl oz of Success/acre/crop.






B. METHOXYFENOZIDE (Intrepid) 2F 16 fl oz — 4 14 MODE OF ACTION GROUP NUMBER1: 18A COMMENTS: Functions both as an ovicide (when applied to eggs and when eggs are laid on residues)

and as a larvicide (must be ingested for it to be effective). C. BACILLUS THURINGIENSIS ssp. KURSTAKI# (various products) Label rates — 4 0 MODE OF ACTION GROUP NUMBER1: 11.B2 COMMENTS: Least harmful to beneficials. Bt is a stomach poison and must be consumed by the

leafroller; therefore it is most effective when applied during warm, dry weather when larvae are actively feeding. Most effective against young larvae. Requires more than 1 treatment; apply second application 7–10 days after first.

** For dilute application, rate is per 100 gal water to be applied in 300-500 gal water/acre, according to label; for

concentrate applications, use 80-100 gal water/acre or lower if the label allows. + Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated

area can be safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.

* Permit required from county agricultural commissioner for purchase or use. # Acceptable for use on organically grown produce. — Not recommended or not on label. 1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-

action Group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a Group number of 1B; chemicals with a 1B Group number should be alternated with chemicals that have a Group number other than 1B. Mode of action Group numbers are assigned by IRAC (Insecticide Resistance Action Committee). For additional information, see their Web site at http://www.irac-online.org/.


Codling Moth (12/09) 11 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

CODLING MOTH (12/09) Scientific Name: Cydia pomonella DESCRIPTION OF THE PEST Codling moth has a 0.5 to 0.75 inch wingspan. The tip of each forewing has a coppery-tinged, dark brown band that distinguishes codling moth from other moths found in apple orchards. Females lay eggs singly on leaves and sometimes on fruit later in the season. The eggs are smaller than a pinhead, disk-shaped, and opaque white when first laid. Just before hatching the black head of the larvae becomes visible. Newly hatched larvae are white with black heads. Mature larvae are 0.5 to 0.75 inch long, pinkish white, with mottled brown heads. Depending on climatic conditions and location in the state, there are two to four generations of codling moth each year. DAMAGE Codling moth has the greatest potential for damage of any apple pest, yet it can be effectively controlled with properly timed treatments. It causes two types of fruit damage: stings and deep entries. Stings are entries where larvae bore into the flesh a short distance before dying. Deep entries occur when larvae penetrate the fruit skin, bore to the core, and feed in the seed cavity. Larvae may enter through the sides, stem end, or calyx end of the fruit. One or more holes plugged with frass on the fruit's surface are a characteristic sign of codling moth infestation. Calyx entries are difficult to detect without cutting the fruit. MANAGEMENT An IPM program uses a combination of tools for codling moth management, including insecticides, mating disruption, and cultural controls. Mating disruption is the preferred tool because of its low toxicity to people, natural enemies, and the environment, but it may need to be supplemented with insecticide sprays, especially during the first few years. In orchards where codling moth is man-aged primarily with insecticides, alternate insecticides that have a different mode of action Group number to avoid the development of resistance. If you see trap catches increasing and suspect insecticide tolerance or resistance, combine the use of mating disruption with the insecticides. All codling moth management programs should be supplemented with cultural controls. Biological Control Alone, natural enemies are not able to keep codling moth populations below economic levels. Aug-mentative releases of the egg parasite Trichogramma platneri have been applied to reduce codling moth populations, but research has shown that this technique has limited effectiveness and is too expensive for practical use. Cultural Control Remove host trees in nearby abandoned orchards (apple, pear, and walnut) to destroy reservoirs of codling moth. Also remove props, picking bins, and fruit piles from the orchard. Proper pruning and orchard sprayer calibration will improve spray coverage. An option for small, organic orchards is hand thinning to remove all infested fruit during each generation, before worms leave fruit, and removal of dropped fruit. Organically Acceptable Methods Organically acceptable tools for the control of codling moth include cultural control in conjunction with mating disruption and sprays of approved oils, codling moth granulovirus (Cyd-X), the Entrust formula-tions of spinosad, and kaolin clay (Surround). Check with your certifier about the exact status of all materials. MONITORING AND TREATMENT DECISIONS IN A MATING DISRUPTION ORCHARD Mating disruption works best in large, uniform orchards that are relatively square in shape. It is not recommended for orchards less than 3-5 acres in size. The larger the contiguous block of mating disrup-tion, the more effective it will be. In orchards with moderate-to-high populations of codling moth and/or in the first year of mating disruption, insecticides or other supplemental controls will likely be needed in addition to the mating disruption program. Using mating disruption successively over a number of years can effectively lower the codling moth population so that alternative, reduced-risk chemical treatments can be effectively used to supplement control when needed.



Setting out pheromone dispensers. Pheromones are deployed as either hand-applied dispensers or in an aerosol canister (puffer). Sprayable pheromones are available but not currently recommended for pome fruit orchards because of their very short residual. Using historical biofix dates to time the application, hang all pheromone products shortly before the first moth emergence in early March to early April. It is important to put out pheromone products early in order to disrupt the mating of overwintering moths as soon as they emerge. A late pheromone application will require supplemental spray treatment. Place hand-applied pheromone dispensers in the upper third of the tree canopy. When placing puffers, put them on the inside of the canopy of edge trees or on the outside of trees in the second row. Upwind placement is one puffer every 50 to 65 feet, and downwind placement is one every 100 to 130 feet, or an average of 20 units per quarter mile. For large blocks, also place a few puffers towards the middle of the orchard on the upwind side. Reapply the dispensers according to the manufacturer's guidelines if the product residual will not last through harvest or through the end of the last generation. Monitoring with traps. Monitor pheromone-treated orchards with traps carefully to help ensure that mated moths have not moved in from adjacent orchards and that the pheromone is successfully disrupting mating. Supercharged (10 mg) pheromone traps. Place pheromone traps with supercharged (10 mg) pheromone lures in the orchard when pheromone dispensers are set out. Put these traps in trees at the same level as the pheromone dispensers. These traps serve to help set the biofix point for degree-day accumulation, which is used to time both fruit sampling and supplemental treatments. Check traps one to two times a week until biofix is set and once a week thereafter. Biofix is the first date that moths are found in traps for three consecutive checks and sunset temperatures have reached 62°F. (Replace lures at the frequency recom-mended by the manufacturer.) Supercharged traps do not attract moths from far, so place as many traps as you can monitor in areas of the orchard that are known hot spots and areas vulnerable to wind where pheromone concentration is likely to be reduced. Examples include high spots and orchard edges; five to six rows inside the orchard is a good location. If the supercharged traps consistently catch high numbers of moths, monitor fruit in the surround-ing area for eggs and damage to determine if a supplemental treatment is necessary. No thresholds have been established for these supercharged traps but 5 moths/week can be considered a relatively high trap count. Regular (1 mg) pheromone traps. Another tool in a mating disruption program is the use of pheromone traps with the regular (1 mg) lures to verify the effectiveness of the mating disruption dispensers. A good idea is to pair a 1 mg trap with a supercharged one. Check traps weekly and replace lures at the frequen-cy recommended by the manufacturer. The supercharged traps should catch a few moths, but the 1 mg traps should not catch any. If moths are caught in the 1 mg traps, check the fruit in the surrounding area. If eggs or damage are found, apply a supplemental treatment to prevent further damage. Traps with regular lures can also be used in upwind border trees (placed in trees in the second row) to monitor the influx and development of codling moth. When moths are caught in these edge traps, it signals the need to monitor fruit. DA lures. A plant-derived chemical (kairomone) lure has been developed to assist in monitoring codling moth populations. This lure is sold commercially as the "DA" lure and is available alone and in combination with pheromone ("combo lure"). The DA lure has been shown to catch both female and male moths, whereas pheromone lures catch only male moths. The sex of moths caught in traps using the DA lure can be determined by observing the tip of the abdomen. If the moth is female, the abdomen can be squeezed to eject the bursa pouch and give some idea of whether the moth is unmated, mated once, or more than once. Generally, if the female's abdomen feels hard to the touch, the moth is most likely mated. The DA lure appears to work best in mating-disrupted apple orchards early in the season. The DA and DA/pheromone combo lure may also be used to assess the success of mating disruption in an orchard, similar to using a supercharged (10X) pheromone lure. Because these lures are relatively new to the market and there appears to be some variability in these lures from one season to the next, use them in conjunction with standard 10X and 1X pheromone lures in order to become familiar with them.



Fruit sampling. Fruit damage can occur even when no moths are caught in traps, so always check fruit for damage towards the latter half of each generation (900 to 1000 degree-days from biofix) and whenever moths are being caught in traps. Examine at least 200 fruit from throughout the orchard as well as in known hot spots and areas vulnerable to wind (edges, high spots), which can reduce pheromone concen-tration. If fruit damage exceeds 0.5%, supplemental sprays should be used for the next generation. If the damage is quite light and very localized along a border, treating five to ten rows along the problem border may be adequate. However, if damage is not clearly localized, or is localized but more than a few percentages, then a larger area or the entire orchard may need to be sprayed. Supplemental treatments. First generation. In orchards with moderate-to-high codling moth populations or if the orchard is in the first year of mating disruption, supplement the mating disruption with an insecticide spray of Altacor, Delegate, Assail, Imidan, Guthion, or Warrior at 250 degree-days after the biofix to target hatching eggs from the first peak of the overwintered moth flight. If monitoring indicates continued flight, apply a second application about 600 to 700 degree-days from the biofix to suppress egg hatch from the second flight peak of the overwintered moths. For low populations, applying a supplemental spray to the first generation may not be necessary. Use trap catch information and monitor fruit to determine if a spray is needed. Using a reduced risk material such as the IGRs (methoxyfenozide-Intrepid) or an organically acceptable alternative (oil, spinosad-Entrust, or codling moth granulovirus – Cyd-X) may be sufficient for control of low populations. Second and third generation. To determine if treatment is needed for subsequent generations, careful trap and fruit monitoring is essential. If treatment is needed, use the guidelines in the section below to determine the best time to spray. MONITORING AND TREATMENT DECISIONS IN A CONVENTIONAL ORCHARD In orchards where codling moth is managed primarily with insecticides, pheromone traps, in conjunction with degree-days and sunset temperatures, are used to determine egg hatch and proper spray timing. When using pheromone traps, keep in mind the many factors, such as tree size, trap density, type of trap, trap placement, brand of pheromone, as well as climatic conditions, that can affect trap counts. Establish first biofix and begin accumulating degree-days. Hang 1 mg pheromone traps in the orchard in mid-March (or at bloom in foothill orchards) about 6 to 7 feet high, with one trap every 10 acres and at least two traps per orchard. The first date that moths are found in traps for three consecutive trap checks and sunset temperatures have reached 62°F is first biofix. (Service traps one to two times a week until biofix is set and once a week thereafter. Replace lures at intervals specified by the manufacturer.) Spray timing. Once biofix is reached, calculate degree-days using a lower threshold of 50°F and an upper threshold of 88°F. (For assistance in calculating degree-days, see "Degree-days" on the UC IPM Web site at http://www.ipm.ucdavis.edu.) The most effective spray timing for each generation is outlined below. For all generations, if high levels of moths are being caught in traps, do not wait until 200–250 degree-days to treat, but apply the first spray at the beginning of egg hatch (160 degree-days). Codling moth has two to four generations each season. Continue to monitor the generations with traps and accumulate degree-days until the crop is harvested or populations decline below damaging levels in September. First generation egg hatch. Two to three sprays may be necessary to adequately control the first generation particularly if the population is high or a short-residual insecticide is used. In addition, if rainfall exceeds 0.5 inch or an irrigation with overhead sprinklers is scheduled within 2 weeks after treatment, a second spray will be needed. Apply the first spray when 250 degree-days have accumulated from the first biofix, unless high levels of moths are being caught, in which case spray at 160 degree days. Make the second and third, if needed, application when the residual effectiveness of the previous spray has ended; this will vary, depending on the chemical used. If trap catches are low or the weather turns too cool for moth activity, you can delay treatment, but continue to monitor.



Second generation egg hatch. Use pheromone trap catches to detect an increase in moth flight activity around 1060 degree-days from the first biofix, which signals the start of the next flight and is the second biofix. For low moth populations, a single application may be sufficient; make this application when 200 to 250 degree-days have accumulated from the second biofix. If you are catching high levels of moths per trap per week, spray at 160 degree-days. If needed, apply a second spray when the residual of the previous spray ends. These two sprays should provide control during the entire egg hatch period. Third generation egg hatch. A third generation of codling moth eggs does not occur every year in every location. Codling moth larvae normally go into diapause (winter dormant state) around August 22, but in warm years and warm locations they will have already started pupation before August 22, and these pupae will soon emerge as adults to produce a third generation. If 650 degree-days have accumulated between the peak of the second generation flight and August 22, most of the codling moth will not go into diapause but will pupate and emerge in August to early September, depending on climate. If degree-day accumulation data indicates a third generation will occur, use pheromone traps to establish a third biofix point around 1100 to 1200 degree-days from the second biofix. Apply a spray when 200 to 250 degree-days have accumulated from the third biofix unless trap catches are high, in which case treat at 160 degree-days. If needed, apply the second spray when the residual of the previous spray ends. Fourth generation egg hatch. In the hottest growing regions of the state, such as the southern San Joaquin Valley, a fourth or partial fourth generation may occur in some years. When flight activity increases around 1100 to 1200 degree-days from the third biofix, establish the fourth biofix. Apply a spray when 200 to 250 degree-days have accumulated from the fourth biofix and, if needed, a second spray when the residual of the previous spray ends. Common name (trade name)



When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. MATING DISRUPTION A. MATING DISRUPTANTS# (Isomate-C Plus, Isomate-C TT)

(CheckMate CM) (Suterra Puffer)

Label rates 0 0

COMMENTS: Apply at biofix just before moth emergence in spring. Hang dispensers high in the tree canopy, about 2 to 4 feet from tree top. If necessary, reapply once at the interval recommended on the label. Monitor weekly with pheromone traps and check fruit after each generation. Most effective on larger blocks of 5–10 acres with trees of uniform size; not effective on smaller irregularly shaped orchards or orchards with varying tree heights. In sites with medium-to-high population levels of codling moth, supplement the pheromone with insecticide treatments.

INSECTICIDE CONTROLS A. CHLORANTRANILIPROLE (Altacor) 3–4.5 oz — 4 5 MODE OF ACTION GROUP NUMBER1: 28 COMMENTS: Do not apply dilute applications of more than 200 gal/acre; use 100–150 gal/acre for best results. B. SPINETORAM (Delegate) WG 4.5–7 oz — 4 7 MODE OF ACTION GROUP NUMBER1: 5





P.H.I.+ (days)

C. ACETAMIPRID (Assail) 70 WP 1.7–3.4 oz — 12 7 MODE OF ACTION GROUP NUMBER1: 4A COMMENTS: Larvicide; use in orchards with moderate-to-high populations. Begin applications 250 DD after

biofix. Residual at 3.4 oz/acre rate is about 14 days. May cause outbreaks of mites, especially in orchards with chronic mite problems; addition of 1% oil (volume by volume) and limiting applications to a single application may help mitigate mite problems. Otherwise, to help prevent the development of insect resistance, limit applications to one generation/year. Repeat applications of any neonicotinoid insecticide (acetamiprid-Assail; imidacloprid- Provado; and thiacloprid-Calypso) can lead to resistance to all neonicotinoids. Alternate neonicotinoids with an insecticide that has a different mode of action Group number to help delay the devel-opment of resistance. To help prevent development of resistance, do not use for both codling moth and aphid control.

D. PHOSMET (Imidan) 70WP 3.5–5.33 lb 0.875–1.33 lb 3 days 7 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Larvicide; use in orchards with high populations. Make applications 250 after biofix. Residual at

the 5.33 lb/acre rate with a pH of 5.5 is about 14 days. E. AZINPHOSMETHYL* (Guthion Solupak) 50WP 1–3 lb 0.25–0.75 lb 14 days 14–21 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Larvicide; use in orchards with high populations. Make applications 250 DD after biofix. Check

label for restricted entry intervals, which vary according to activity. Early in the season, azinphosmethyl applied at the low rate is not very disruptive to beneficials; after May, however, this is no longer true. Use the low rate when no more than 2 weeks residual control is required, or no more than 10 moths/trap have been caught before first moth treatment and seasonal trap catches the previous season did not exceed 30 moths/trap. In areas where resistance to azinphosmethyl is present in the codling moth population, even high label rates of this material may not be effective. If the last application is greater than 2 lb/acre, the preharvest interval is 21 days; if it is less than or equal to 2 lb/acre, it is 14 days.

F. LAMBDA-CYHALOTHRIN* (Warrior with Zeon) 2.56–5.12 fl oz — 24 21 MODE OF ACTION GROUP NUMBER1: 3 COMMENTS: Larvicide; use in orchards with moderate-to-high populations. Make applications 250 DD after

biofix. Residual at the 5 oz/acre rate is about 21 days. G. THIACLOPRID (Calypso) 6–8 fl oz 1.5–2 fl oz 12 30 MODE OF ACTION GROUP NUMBER1: 4A COMMENTS: Larvicide; use in orchards with moderate populations. Make applications 250 after biofix.

Residual at the 8 oz/acre rate is about 14 days. May cause outbreaks of mites, especially in orchards with chronic mite problems; addition of 1% oil (volume by volume) and limiting applications to a single application may help mitigate mite problems. Otherwise, to help prevent the development of insect resistance, limit applications to one generation/year. Repeat applications of any neonicotinoid insecticide (acetamiprid-Assail; imidacloprid- Provado; and thiacloprid-Calypso) can lead to resistance to all neonicotinoids. Alternate neonicotinoids with an insecticide that has a different mode of action Group number to help delay the devel-opment of resistance. To help prevent development of resistance, do not use for both codling moth and aphid control.

H. METHOXYFENOZIDE (Intrepid) 2F 16 fl oz — 4 14 MODE OF ACTION GROUP NUMBER1: 18A COMMENTS: Use only in orchards with low-to-moderate populations. Functions both as an ovicide (when

applied to eggs and when eggs are laid on residues) and as a larvicide (larvae must ingest it for it to be effective). Apply at 100 DD from first biofix and again in 10 to 18 days if flights are extended.






I. SPINOSAD (Entrust) # 2–3 oz 0.5–0.75 oz 4 7 MODE OF ACTION GROUP NUMBER1: 5 COMMENTS: Use only in orchards with low-to-moderate populations or as a supplement to mating disrup-

tion. Tank mixing with 1% oil (volume by volume) increases efficacy: oil suppresses egg hatch and spinosad kills young larvae that ingest it. Apply 200 DD from first biofix, and reapply at 10-day intervals if continued coverage is needed. Do not apply more than 9 oz/acre/season.

J. CYDIA POMONELLA GRANULOVIRUS# (Cyd-X) 1–6 fl oz — 4 0 COMMENTS: Use only in orchards with low-to-moderate populations or as a supplement to mating disrup-

tion. A larvicide; larvae must ingest to become infected by this virus. Make first application at 200 to 250 DD. Make a second application 7 to 10 days later, a third application at 600 DD and a fourth 7 to 10 days later for a total of 4 applications per flight. The use of oil will help to provide increased control by distributing the virus better over leaf surfaces and serving as an ovicide by suffocating eggs. May also be tank-mixed with acetam-iprid (Assail) for increased efficacy of both materials. For tank mixes, observe all directions for use on all labels, and employ the most restrictive limits and precautions. Never exceed the maximum a.i. on any label when tank mixing products that contain the same a.i.

K. KAOLIN CLAY# (Surround) 25–50 lb — 4 0 MODE OF ACTION: Unknown. An inorganic insecticide. COMMENTS: Best used as a supplement to mating disruption and where population pressure is quite low.

Serves primarily as a barrier to oviposition and/or to prevent larvae from entering the fruit so early application and good coverage are important. Make the first application at 100 DD after the biofix, and reapply in 7 to 14 days in 100-200 gal water/acre or sufficient water for complete coverage. A total of 3 treatments per generation may be required to keep fruit completely covered during the egg-laying period. Because of potential for interfering with fruit finish in some varieties, this material may not be the best choice for later generations.

L. NARROW RANGE OIL# — 1–1.5 gal 4 when dry MODE OF ACTION: Contact including smothering and barrier effects. COMMENTS: Best used as a supplement to mating disruption and where population pressure is quite low.

Functions as both an ovicide and larvicide. Oils are mildly effective against codling moth eggs and work by smothering them; they need to be reapplied frequently during egg-laying period, which is anytime moths are flying. Begin oil applications at 100 to 200 DD after the biofix. Reapply every 7 to 10 days as long as significant flight is occurring. Good coverage is essential. Effectiveness may be enhanced with more dilute applications (i.e., 200–400 gal water/acre). Oils may be phytotoxic if used within a few weeks of a sulfur or captan spray or if applied at higher rates during hot weather (above 90°F). May be used to maintain lower populations in mating-disrupted orchards. May cause a greasy appearance to some fruit if applied close to harvest or with high seasonal volumes. Check with certifier to determine which products are organically acceptable.

** For dilute application, rate is per 100 gal water to be applied in 300–500 gal water/acre, according to label; for concentrate

applications, use 80–100 gal water/acre or lower if the label allows. + Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be

safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.

* Permit required from county agricultural commissioner for purchase or use. # Acceptable for use on organically grown produce. — Not recommended or not on label. 1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action

Group number more than twice per season to help prevent the development of resistance. For example, the organophos-phates have a Group number of 1B; chemicals with a 1B Group number should be alternated with chemicals that have a Group number other than 1B. Mode of action Group numbers are assigned by IRAC (Insecticide Resistance Action Commit-tee). For additional information, see their Web site at http://www.irac-online.org/.


Cribrate Weevil (8/06) 17 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

CRIBRATE WEEVIL (8/06) Scientific Name: Otiorhynchus cibricollis DESCRIPTION OF THE PEST The adult cribrate weevil is dark brown to almost black. It is about 0.33 inch (8 mm) long and has longi-tudinal striations on its back. Adult emergence often begins in late May and adults are present all summer. They are nocturnal and flightless - hiding in cracks in the soil, under clods, or between fruit during the day. At night, they emerge and crawl up the trunk to feed on foliage. DAMAGE Young trees may be stunted or killed by defoliation and bark feeding. Damage on mature trees is most serious when a large population feeding on the petiole results in premature fruit drop, water stress, and subsequent smaller fruit size and yield. Notching out of the edge of the leaf is characteristic of initial foliar feeding giving the leaf a ragged appearance. With higher populations, the whole leaf except the veins, as well as the bark on twigs and pedicels may be consumed. Young trees are particularly suscepti-ble to defoliation, stunting, and tree loss. The white larvae overwinter on the roots but have not been associated with significant damage to apple trees. MANAGEMENT Cribrate weevil is an occasional pest of apple trees in the Central Coast and foothill regions. No currently registered insecticide treatments have been shown to be effective against this pest. Preplant fumigation may reduce potential problems, but for existing trees the primary control is application of sticky material to the trunk. A three- to four-inch band of sticky material such as Tanglefoot will prevent adult weevils from climbing the trunk. The sticky material needs to be re-applied when it becomes dirty. While applica-tions of these sticky substances have not appeared to cause phytotoxicity, thin bark will slough off, and it may be safer to apply these materials over tape or painted areas. Apply azinphosmethyl (Guthion) sprays for codling moth at night when the beetles are active appears to provide some control.


European Red Mite (3/09) 18 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

EUROPEAN RED MITE (3/09) Scientific Name: Panonychus ulmi DESCRIPTION OF THE PEST European red mites overwinter as eggs; eggs hatch in spring when trees bloom. With the use of a hand lens, look for overwintering eggs in roughened bark at bases of buds and spurs on smaller branches and twigs, or in wounds. They are globular and red with a slender stalk (stipe) rising from the top center and many grooves extending from top to bottom. During the growing season, eggs are laid on leaves. There are three instars before the adult stage. Immature mites are bright red, except just after molting when they appear bright green. The green color turns to red after the mites resume feeding. Adults are dark red and have six to eight white spots at the base of hairs on the back. DAMAGE Severe mite infestations can cause bronzing of leaves. Damage is relatively less severe on wide leaf varieties such as Yellow Newton and more severe on narrow leaf varieties such as Red Delicious. MANAGEMENT European red mite only occasionally becomes troublesome in apple orchards. Monitor in winter to determine the need for treatment. Dormant oil is the preferred treatment. Biological Control If European red mite populations are managed at low levels by treating with a dormant oil, predators including western predatory mite, sixspotted thrips and spider mite destroyer can effectively help to maintain low levels throughout the season. Minimize the use or dosages of materials disruptive to mite predators. Avoid spraying with materials such as lime sulfur which kill the apple rust mite. When apple rust mites are allowed to survive, the predaceous mites feed on them and can build up large enough populations to control European red mites in some areas of California. Cultural Control Minimize the potential for mite problems by reducing dusty conditions within the orchard and keeping the trees well irrigated. Organically Acceptable Methods Biological and cultural controls and sprays of approved narrow range oils are organically acceptable. Monitoring and Treatment Decisions Anytime during winter collect 25 to 100 fruit spurs from trees throughout the block. If less than 10% of the spurs are infested, European red mite probably will not become a problem that season. If more than 10% of the spurs are infested, an oil spray should be applied before bloom. Control improves the closer eggs are to hatching. If summer control becomes necessary, the thresholds range from 10 to 30 mites per leaf depending on the age, variety, and condition of the tree, and the abundance of the mite predators. Common name (trade name)



When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. DELAYED DORMANT (Preferred timing) A. NARROW RANGE OIL# 6 gal 1.5 gal 4 0 MODE OF ACTION: Contact including smothering and barrier effects. COMMENTS: Check with certifier to determine which products are organically acceptable.






FOLIAGE SPRAY A. ABAMECTIN* (Agri-Mek) 0.15EC 10–20 oz 2.5–5 oz 12 28

MODE OF ACTION GROUP NUMBER1: 6 COMMENTS: Narrow-spectrum preventive material that can be applied early in the season (from petal fall to 6

weeks later) when mite outbreaks are anticipated. Use with a horticultural spray oil. B. CLOFENTEZINE (Apollo) 50SC 4–8 oz 1–2 oz 12 45

MODE OF ACTION GROUP NUMBER1: 10A COMMENTS: For early and mid-season mite control; easy on natural enemies. Kills eggs. Need to apply early,

before monitoring indicates a need; use in orchards where European red mite is a chronic pest. Good coverage is a must; use a minimum of 50 gal water/acre for concentrate sprays and a maximum of 400 gal water/acre for dilute. To delay development of resistance, use only once per season.

C. FENBUTATIN-OXIDE* (Vendex) 50WP 1–2 lb 4–8 oz 48 14

MODE OF ACTION GROUP NUMBER1: 12B COMMENTS: The liquid formulation gives better control in cooler climates. Do not apply more than 2

times/season. Do not apply more than 4 lb/acre/year. D. PYRIDABEN (Nexter) 5.2 oz 1.3 oz 12 25

MODE OF ACTION GROUP NUMBER1: 21 COMMENTS: Can be used later in the season than preceding materials and is easier on beneficials than dicofol,

but more disruptive than fenbutatin-oxide (Vendex). Do not use less than 100 gal water/acre spray volume. Most effective with use of a silicone spreader.

E. HEXYTHIAZOX (Savey) 50 WP Low to mid-label rate 12 28 MODE OF ACTION GROUP NUMBER1: 10B COMMENTS: Kills eggs. Need to apply early, before monitoring indicates a need; use in orchards where

European red mite is a chronic pest. Apply only once per growing season. F. FENPYROXIMATE (FujiMite) 5EC 1–2 pt — 12 14 MODE OF ACTION GROUP NUMBER1: 21 COMMENTS: New material and there is little experience in California regarding efficacy and effect on

beneficials. Most effective with use of a silicone spreader. G. ETOXAZOLE (Zeal) 2–3 oz 0.5–0.75 oz 12 28 MODE OF ACTION GROUP NUMBER1: 10B COMMENTS: Preliminary research indicates etoxazole has an effect on the reproductive capacity of predatory

mites. Most effective with use of a silicone spreader. H. BIFENAZATE (Acramite) 50WS 0.75–1 lb 0.25 lb 12 7 MODE OF ACTION GROUP NUMBER1: 25 COMMENTS: Only one application/crop/year. Most effective with use of a silicone spreader.






I. DICOFOL (Kelthane) Label rates 48 7

MODE OF ACTION: UNC COMMENTS: For use on late-season mite outbreaks. This material is harsh on beneficials so its use is best late

in the season when necessary.

** For dilute application, rate is per 100 gal water to be applied in 300-500 gal water/acre, according to label; for concentrate applications, use 80-100 gal water/acre or lower if the label allows.

+ Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.

* Permit required from county agricultural commissioner for purchase or use. # Acceptable for use on organically grown produce. 1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action



Eyespotted Bud Moth (3/09) 21 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

EYESPOTTED BUD MOTH (3/09) Scientific Name: Spilonota ocellana DESCRIPTION OF THE PEST Eyespotted bud moth has become an important pest in organic apple orchards in coastal areas but is not a problem in the interior valleys. Larvae are dull brown caterpillars with a shiny black head. Adult moths are gray and similar in appearance to a codling moth but smaller and with a white band across the mid-section. In California, two generations per year have been observed. Adults of the overwintering generation appear in May and lay eggs, which hatch in late June and July. Larvae feed on leaves and the surface of fruits throughout summer. The summer generation adults emerge in September and October. It is believed that the larvae produced by the summer generation overwinter in hibernacula. These larvae emerge in late winter, pupate in spring, and emerge as adults in May. The life cycle and damage from eyespotted bud-moth is similar to the apple pandemis moth, and they may co-exist in the same orchard. DAMAGE Larvae feed primarily on emerging buds and leaves in spring. They roll leaves later in spring and pupate in these leaf rolls. The leaf rolls often contain a dead leaf in the center. Larvae of the summer generation feed on leaves; the first sign of egg hatch is often windowpaning of leaves where small areas are chewed out leaving just a web of veins. Check with a hand lens for the presence of the small brown larvae in windowpaned areas. Larvae also attach leaves to the fruit with silk and feed on the fruit under the attached leaf, making individual, shallow feeding marks. MANAGEMENT Eyespotted bud moth is primarily a pest in organic apple orchards where pheromone mating disruption for codling moth control is used. In conventional orchards, synthetic pesticides applied for other pests easily control eyespotted budmoth. This insect has become a pest in organic apple orchards only in recent years, and effective control measures are still being evaluated. Monitor eyespotted bud moth flights with pheromone traps, which should be placed in the orchard by May 1. Maintain traps through the growing season. Treatments may be warranted in organic apple orchards. Common name (trade name)



When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. DELAYED DORMANT/PRE-BLOOM AND LATE JUNE/JULY A. SPINOSAD (Entrust)# 2–3 oz 0.67–1 oz 4 7 MODE OF ACTION GROUP NUMBER1: 5 COMMENTS: A maximum of one prebloom spray and two sprays 7–10 days apart in late June and July after

the first windowpaning is observed is suggested. Do not apply more than 9 oz of Entrust/acre/year. No more than three sprays of Entrust applied for leafrollers are recommended on the label. Alternation with Bacillus thuringiensis may help delay development of resistance.

B. BACILLUS THURINGIENSIS ssp. KURSTAKI# (various products) Label rates Label rates 4 0 MODE OF ACTION GROUP NUMBER1: 11.B2 COMMENTS: A maximum of one prebloom spray and one early bloom spray as well as two sprays 7–10

days apart in late June and July after the first windowpaning is observed is suggested. Alternate with Entrust for resistance management. Most effective when applied during warm, dry weather and while larvae are small.

** For concentrate applications, use the amount given in 80–100 gal water/acre, or lower if the label allows; for dilute applications, amount is per 100 gal water to be applied in 300–400 gal water/acre, according to label.


# Acceptable for use on organically grown produce. 1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action

Group number more than twice per season to help prevent the development of resistance. For example, the organophos-phates have a Group number of 1B; chemicals with a 1B Group number should be alternated with chemicals that have a Group number other than 1B. Mode of action Group numbers are assigned by IRAC (Insecticide Resistance Action Committee). For additional information, see their Web site at http://www.irac-online.org/.


Fruittree Leafroller (3/09) 22 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

FRUITTREE LEAFROLLER (3/09) Scientific Name: Archips argyrospila DESCRIPTION OF THE PEST Fruittree leafroller overwinters in the egg stage in irregular masses of 30 to 100 eggs cemented over with a secretion. Young larvae are light green caterpillars with black heads and are first seen at bud break. The mature larva is about an inch long and has a green body and black head. The black head helps distin-guish fruittree leafroller from other leafrollers. There is one generation per season. DAMAGE The fruittree leafroller feeds principally on leaves, but also feeds on blossoms, flower buds, and fruits during bloom. Tiny larvae work their way into opening leaf buds to feed. Once the tree has leafed out, larvae tie up leaves and live within leafrolls, feeding on leaves or fruit. Larvae damage fruit in much the same way as green fruitworms, resulting in shallow cavities in the fruit. Damaged fruits that remain on the tree develop deep bronze-colored scars with roughened, netlike surfaces. MANAGEMENT Generally fruittree leafrollers are the first caterpillars seen in samples taken after green tip and have about 2 weeks to feed before the first codling moth spray goes on. Young larvae are easiest to control because they have not yet constructed a nest out of leaves, which protects them from insecticides. Biological Control Natural enemies specific for fruittree leafroller are not known, but a number of general predators, such as lacewing and lady beetle larvae, and parasites feed on fruittree leafroller larvae. Although these natural enemies help keep fruittree leafroller populations at low, nondamaging levels; occasional outbreaks still occur, especially in the San Joaquin and inner coastal valleys. Organically Acceptable Methods Applications of approved narrow range oil, Bacillus thuringiensis, and the Entrust formulation of spinosad are organically acceptable. Monitoring and Treatment Decisions Fruittree leafroller usually is effectively controlled by a dormant oil spray. Make an application thorough enough to cover egg masses. Check results by sampling for leafrollers at green tip. Examine 100 fruit clusters per block. If no worms are found, resample in 1 week. If more than one worm is found, treatment before pink bud may be necessary to prevent damage. Often infestations are usually confined to small, localized areas of the orchard and can be spot treated.




When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. DELAYED DORMANT A. NARROW RANGE OIL# 6 gal 2 gal 4 0 MODE OF ACTION: Contact including smothering and barrier effects. COMMENTS: Check with certifier to determine which products are organically acceptable. B. NARROW RANGE OIL 4 gal 1.5 gal 4 0 MODE OF ACTION: Contact including smothering and barrier effects. . . . PLUS . . . CHLORPYRIFOS* (Lorsban) 4EC Label rates 4 days 0 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Avoid drift and runoff into surface waters or choose alternative materials. Chlorpyrifos has

been found in surface waters at levels that violate federal and state water quality standards.


Fruittree Leafroller (3/09) 23 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html




C. METHIDATHION* (Supracide) 2EC 3 qt 1 qt 3 days 0 MODE OF ACTION: An organophosphate (Group 1B)1 insecticide. PINK BUD to PETAL FALL A. BACILLUS THURINGIENSIS ssp. KURSTAKI# (various products) Label rates — 4 0 MODE OF ACTION GROUP NUMBER1: 11.B2 COMMENTS: Least harmful to beneficials. Bt is a stomach poison and must be consumed by the leafroller;

therefore it is most effective when applied during warm, dry weather when larvae are actively feeding. Effective against young larvae. Requires more than 1 treatment; apply second application 7–10 days after first.

B. SPINOSAD (Entrust)# 2–3 oz 0.5–0.75 oz 4 7 (Success) 6–10 fl oz 2–3.3 fl oz 4 7 MODE OF ACTION GROUP NUMBER1: 5 COMMENTS: Apply at petal fall. To prevent the development of resistance to this product, rotate to a

material with a different mode of action after treating two consecutive generations. Do not apply more than 3 sprays/season directed at leafrollers. Do not apply more than 9 oz/acre/crop of Entrust or 29 fl oz of Success/acre/crop.

C. METHOXYFENOZIDE (Intrepid) 2F 16 fl oz — 4 14 MODE OF ACTION GROUP NUMBER1: 18A COMMENTS: Functions both as an ovicide (when applied to eggs and when eggs are laid on residues) and as

a larvicide (must be ingested for it to be effective). For each generation, begin applications at early egg hatch before webbing and sheltering begin. Make a second application in 10–14 days. Spray coverage is extremely important. Ground application should use 200 gal water/acre with a sprayer speed of 1.5 mph. The addition of a spray adjuvant is recommended to enhance spray coverage.

D. CHLORANTRANILIPROLE (Altacor) 3–4.5 oz — 4 14 MODE OF ACTION GROUP NUMBER1: 28

COMMENTS: Do not apply dilute applications of more than 200 gal/acre; use 100–150 gal/acre for best results.

E. SPINETORAM (Delegate) WG 4.5–7 oz — 4 7 MODE OF ACTION GROUP NUMBER1: 5 ** For dilute application, rate is per 100 gal water to be applied in 300-500 gal water/acre, according to label; for concentrate

applications, use 80-100 gal water/acre or lower if the label allows. + Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be





Green Apple Aphid (1/11) 24 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

GREEN APPLE APHID (1/11) Scientific Name: Aphis pomi DESCRIPTION OF THE PEST Overwintering eggs are found on twigs of the previous season's growth and on fruit spurs. They are identical in appearance to rosy apple aphid eggs: shiny, black, and football shaped. Newly hatched apple aphids are dark green. Mature aphids on apple foliage in spring and summer have a bright, yellow-green abdomen with darker green lateral spots. DAMAGE Green apple aphids infest succulent terminal growth and when infestations are severe will also be found on fruits. High populations on young trees may seriously retard normal growth and result in irregular shoot growth. On bearing trees, heavy infestations of aphids may cover the fruit and foliage with honey-dew on which a black, sooty mold develops. The mold can hinder leaf function and lower fruit grade. MANAGEMENT Green apple aphid feeds on both apple and pear trees and occasionally on hawthorn, loquat, pyracantha, and quince; apple, however, is the preferred host. Although green apple aphid is subject to wide fluctua-tions in abundance, it generally occurs yearly in most apple orchards. Natural enemies often control this aphid. Biological Control There are many natural enemies which feed on aphids. Among the most important are lady beetles, green lacewings, brown lacewings, and syrphid fly larvae. Organically Acceptable Methods Biological controls and sprays of insecticidal soap, approved narrow range oils, and azadirachtin (Nee-mix) are organically acceptable. Monitoring and Treatment Decisions A delayed dormant spray of oil will prevent early injury and should eliminate the need for further sprays. If more than 45% of the tree's shoots are infested during the summer, assess the abundance of predators. Treatment may be warranted if 60% or more of the tree's terminals are infested. Spring treatments may also be necessary for young trees with severe infestations. Common name (trade name)



When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. DELAYED DORMANT (Preferred timing) A. DORMANT FLOWABLE EMULSION OIL 4–6 gal 1–1.5 gal 4 0 MODE OF ACTION: Contact including smothering and barrier effects. COMMENTS: Apply at delayed dormant to silver tip stage. FOLIAGE SPRAY A. SPIROTETRAMAT (Movento) 6–9 fl oz — 24 7 MODE OF ACTION GROUP NUMBER1: 23 COMMENTS: Do not apply until after petal fall. Allow 14 days between applications. Maximum is 25 fl

oz/acre (0.4 lb a.i./acre)/crop/season.


Green Apple Aphid (1/11) 25 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html




B. IMIDACLOPRID (Provado) 1.6F 8 oz 2 oz 12 7 MODE OF ACTION GROUP NUMBER1: 4A COMMENTS: Provides good control. Allow 10 days between applications. Repeat applications of any neonico-

tinoid insecticide (acetamiprid-Assail; imidacloprid- Provado; and thiacloprid-Calypso) can lead to resistance to all neonicotinoids. Alternate neonicotinoids with an insecticide that has a different mode of action to help delay the development of resistance. To help prevent development of resistance, do not use for both codling moth and aphid control.

C. ACETAMIPRID (Assail) 70 WP 1.7-3.4 oz — 12 7 MODE OF ACTION GROUP NUMBER1: 4A COMMENTS: May cause outbreaks of mites, especially in orchards with chronic mite problems; addition of 1%

oil (volume by volume) and limiting applications to a single application may help mitigate mite problems. Repeat applications of any neonicotinoid insecticide (acetamiprid-Assail; imidacloprid- Provado; and thiaclo-prid-Calypso) can lead to resistance to all neonicotinoids. Alternate neonicotinoids with an insecticide that has a different mode of action to help delay the development of resistance. To help prevent development of resistance, do not use for both codling moth and aphid control.

D. DIAZINON* 4 lb 1 lb 4 days 21 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Applications made during the foliage season are harmful to beneficials. Avoid drift and

tailwater runoff into surface waters. E. INSECTICIDAL SOAP# Label rates 12 0 (M-Pede) MODE OF ACTION: A contact insecticide with smothering and barrier effects. COMMENTS: More than 1 application may be necessary because this material has little residual action. F. NARROW RANGE OIL# (JMS Stylet Oil, Omni, etc.) Label rates see label 0 MODE OF ACTION: Contact including smothering and barrier effects. COMMENTS: Apply as soon as colonies are found and reapply at 7- to 10-day intervals as long as active

colonies are found. G. NARROW RANGE OIL# (JMS Stylet Oil, Omni, etc.) Label rates see label

0

MODE OF ACTION: Contact including smothering and barrier effects. . . . PLUS . . . AZADIRACHTIN# (Neemix) Label rates 12 0 MODE OF ACTION GROUP NUMBER1: 18B COMMENTS: Apply as soon as colonies are found and reapply at 7- to 10-day intervals as long as active

colonies are found. Azadirachtin without oil is not effective in controlling this pest. ** For dilute application, rate is per 100 gal water to be applied in 300–500 gal water/acre, according to label; for concentrate






Green Fruitworms (3/09) 26 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

GREEN FRUITWORMS (3/09) Scientific Names: Speckled green fruitworm: Orthosia hibisci Humped green fruitworm: Amphipyra pyramidoides DESCRIPTION OF THE PESTS Immature larvae of both species are light green caterpillars. Mature green fruitworms have green bodies and green heads. Speckled green fruitworms have cream-colored lines down the back and sides of the body. Humped green fruitworms are distinguished by a prominent hump on the last segment, bright yellow lines on the side, and less distinct white lines on the back. They have only one generation a year. Egg hatch extends from pink bud to after petal fall. DAMAGE Young green fruitworm larvae feed on leaves. Fruit feeding usually begins about petal fall and continues until larvae have completed their development. At harvest, these fruit are misshapen and have large, roughened, russeted cavities. MANAGEMENT Green fruitworm populations in an orchard are usually spotty; often they occur near borders where windbreaks and other trees serve as sources of infestation. Delayed dormant treatments containing organophosphates applied for other pests may control green fruitworms. In orchards where a delayed dormant spray was not applied, green fruitworms can become a problem. Monitor to determine need for treatment. Organically Acceptable Methods Sprays of Bacillus thuringiensis and the Entrust formulation of spinosad are organically acceptable. Monitoring and Treatment Decisions Because populations of green fruitworm are often spotty within an orchard, thoroughly sample each block. Three sampling methods may be used: (1) Inspect 100 fruit clusters for presence of worms; (2) Take 50 beating-tray samples, especially around petal fall when larvae are easy to dislodge; (3) Inspect a block for a half hour looking for damaged foliage and clusters. When one or more larvae per 100 clusters or 50 beating tray samples are found, treatment may be necessary. Common name (trade name)



When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. A. BACILLUS THURINGIENSIS ssp. KURSTAKI# (various products) Label rates — 4 0 MODE OF ACTION GROUP NUMBER1: 11.B2 COMMENTS: Apply at bloom or petal fall. Least harmful to beneficials. Bt is a stomach poison and must be

consumed by the caterpillar; therefore, it is most effective when applied during warm, dry weather when larvae are actively feeding. Most effective against young larvae. Requires more than 1 treatment; apply second application 7–10 days after first.

B. SPINOSAD (Entrust)# 2–3 oz 0.5–0.75 oz 4 7 (Success) 6–10 oz 2–3.3 oz 4 7 MODE OF ACTION GROUP NUMBER1: 5 COMMENTS: Apply at pink bud or petal fall when monitoring indicates larvae are present. To prevent the

development of resistance to this product rotate to a material with a different mode of action after treating two consecutive generations. Do not apply more than 3 sprays/season directed at leafrollers.


Green Fruitworms (3/09) 27 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html





a larvicide (must be ingested for it to be effective). For each generation, begin applications at early egg hatch before webbing and sheltering begin. Make a second application in 10–14 days. Spray coverage is extremely important. Ground application should use 200 gal water/acre with a sprayer speed of 1.5 mph. The addition of a spray adjuvant is recommended to enhance spray coverage.



E. SPINETORAM (Delegate) WG 4.5–7 oz — 4 7 MODE OF ACTION GROUP NUMBER1: 5 F. AZINPHOSMETHYL* (Guthion) 50WP 1 lb 0.25 lb 14 days 14 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Apply at petal fall. Check the label for restricted entry intervals, which vary according to

activity. G. DIAZINON* 50WP 2 lb 0.5 lb 14 days 21 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Apply during delayed dormancy or at petal fall. Avoid drift and tailwater runoff into surface

waters. ** For dilute application, rate is per 100 gal water to be applied in 300–500 gal water/acre, according to label; for concentrate






Italian Pear Scale (3/09) 28 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

ITALIAN PEAR SCALE (3/09) Scientific Name: Epidiaspis leperii DESCRIPTION OF THE PEST Italian pear scale overwinters mostly as a mature scale. The cover is circular, about 0.06 inch in diameter, and light gray, but with a brown peak slightly off-center. Underneath the covering, the female's body is reddish purple. DAMAGE This scale does not attack fruit, but feeds directly on the wood of the tree, affecting tree vigor and causing reduced fruit size. Apple trees can tolerate fairly high populations of this scale without any apparent damage. MANAGEMENT Although widely distributed, Italian pear scale is rarely a pest in commercial apple orchards. Organically Acceptable Methods Lime treatments are organically acceptable. Treatment Decisions Generally, dormant sprays applied for other scales keep Italian pear scale under control unless limbs are heavily covered with moss and lichens. In this case, remove the moss and lichen or add Bordeaux mixture to the dormant spray to kill them. For more information on Bordeaux mixtures and how to mix them, see UC IPM Pest Note: Bordeaux Mixture, ANR Publication 7481 (available online).


Leafhoppers (3/09) 29 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

LEAFHOPPERS (3/09) Scientific Names: White apple leafhopper: Typhlocyba pomaria Rose leafhopper: Edwardsiana rosae DESCRIPTION OF THE PESTS There are two generations of white apple leafhopper per year. Eggs of this species overwinter in the apple trees and hatch shortly after bloom. Adults of the first generation appear in the last part of May to early June. Nymphs of the second generation develop in July and August. Rose leafhoppers do not overwinter in apple trees; instead they overwinter on plants of the rose family such as blackberries. In spring, the first generation develops on the overwintering host; adults then migrate to other hosts, including apples. The second generation and apparently a third generation may be spent on apples. This species often reaches great abundance near to or after apple harvest. The adults of both species are white, about 0.12 inch long and cannot be readily distinguished from one another. Rose leafhopper populations can be identified by the presence of black spots at the base of thoracic setae on older nymphs; these spots are not found on nymphs of the white apple leafhoppers. DAMAGE Leafhoppers feed by sucking on leaf tissue. Their feeding causes a white stippling on leaves. In heavy infestations, fruit may be reduced in size and buds may be weakened. Excrement dropped by leafhoppers will appear as black specks on apples. These specks are easily removed by washing. Leafhoppers also produce honeydew, which forms into sticky droplets around the calyx end after rainfall or overhead sprinkling, and is not easily removed. MANAGEMENT White apple leafhopper has become an increasing problem in the past decade because it has developed resistance to organophosphate insecticides. Start monitoring at petal fall to determine need for treatment. Biological Control Parasites of the white apple or rose leafhopper have not been studied in California apple orchards. In other areas, parasitization of eggs may be significant in holding populations in check. Monitoring and Treatment Decisions Insecticides are most effective when applied during the first four nymphal instars of the first generation, especially in the fourth instar. These stages occur between petal fall and the first codling moth spray. Start monitoring for this leafhopper at petal fall. At weekly intervals sample four leaves per tree from 25 trees dispersed throughout the orchard. Peak nymphal emergence typically occurs 3 to 4 weeks after the first nymphs are found. Treatment is warranted when populations exceed an average of 0.5 nymphs per leaf or when 30% of the leaves are infested. Rose leafhopper is a concern when high populations of nymphs exist near harvest; treatment of nymphs may be warranted at this time. Common name (trade name)



When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. A. IMIDACLOPRID (Provado) 1.6F 4–8 fl oz 1–2 fl oz 12 7 MODE OF ACTION GROUP NUMBER1: 4A COMMENTS: Allow 10 days between applications. Repeat applications of any neonicotinoid insecticide

(acetamiprid-Assail; imidacloprid- Provado; and thiacloprid-Calypso) can lead to resistance to all neonico-tinoids. Alternate neonicotinoids with an insecticide that has a different mode of action to help delay the development of resistance.


Leafhoppers (3/09) 30 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html




B. ACETAMIPRID (Assail) 70WP 1.1–1.7 fl oz 0.275–0.425 fl oz 12 7 MODE OF ACTION GROUP NUMBER1: 4A COMMENTS: Repeat applications of any neonicotinoid insecticide (acetamiprid-Assail; imidacloprid-

Provado; and thiacloprid-Calypso) can lead to resistance to all neonicotinoids. Alternate neonicotinoids with an insecticide that has a different mode of action to help delay the development of resistance.

C. INDOXACARB (Avaunt) 5–6 fl oz — 12 14 MODE OF ACTION GROUP NUMBER1: 22 COMMENTS: Must be timed for leafhoppers and not other pests to be effective. Do not apply dilute applica-

tions of more than 200 gal water/acre. For best results, use 50-150 gal water/acre. Minimum interval between treatments is 7 days. Make no more than 4 applications/season or 3 applications before hand-thinning.

D. DIAZINON* 50WP 3–4 lb 0.75–1 lb 4 days 21 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Apply when nymphal stages are present. Applications made during the foliage season are very

disruptive of beneficials. Avoid drift and tailwater runoff into surface waters. E. CARBARYL* (Sevin) 80S 1.875 lb 0.5 lb 12 3 MODE OF ACTION GROUP NUMBER1: 1A COMMENTS: Will thin apples up to 30 days after full bloom. May cause severe outbreaks of spider mites.

One application early in the season does not cause mite increase in coastal areas. F. ENDOSULFAN* (Thionex) 50WP 4 lb 1 lb 4 days 30 MODE OF ACTION GROUP NUMBER1: 2A ** For dilute application, rate is per 100 gal water to be applied in 300–500 gal water/acre, according to label; for concentrate



* Permit required from county agricultural commissioner for purchase or use. — Not recommended or not on label. 1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action



Leafminers (3/09) 31 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

LEAFMINERS (3/09) Scientific Name: Phyllonorycter spp. DESCRIPTION OF THE PEST Adults are small, golden brown moths with white bands or spots that give them a silvery appearance when they fly in sunlight. In spring eggs are laid in young leaves during the period from the tight cluster bloom stage through petal fall. Larvae develop within the leaf tissue. The first three instars feed on sap within the leaves and are called sap-feeders. Sap-feeders have a white, flat, legless body with a brown, wedge-shaped head. They form snakelike mines in the leaf that are visible only on the lower surface of leaves. Fourth and fifth stage larvae are known as tissue-feeders because feeding is concentrated more on leaf tissue than on sap. Tissue feeders have both legs and prolegs and a round head. These older larvae tie the sides of the leaf together with silk to form tents. Leafminers overwinter within mines in leaves on the orchard floor. DAMAGE Leafminer damage is restricted to foliage. In a heavy infestation, over 60% of the leaf tissue can be destroyed. Larvae feed on cells between upper and lower epidermal layers of the leaf, leaving only the thin epidermal layers. The upper side of the leaf takes on a light, spotted appearance. Infestations greater than an average of 5 to 10 mines per leaf may cause premature defoliation. Even if trees are not defoliat-ed, leaf function is impaired, and fruit may fail to size or color. MANAGEMENT Low levels of leafminer populations are present in most orchards every year; populations are usually kept at low levels by several species of parasites. Leafminers only become pests when their natural enemies are disrupted by the use of broad-spectrum insecticides for codling moth control. Biological Control Parasitic wasps such as Pnigalio flavipes and Sympiesis stigmata are very important in controlling tentiform leafminers. One of the common leafminer parasites lays its eggs in the leaf mines when the leafminers have reached the tissue-feeding stage or fourth instar. After hatching, parasitic larvae attach themselves to the outside of leafminer larvae. The parasite grows rapidly and consumes the leafminer by its fifth instar. It then pupates within the leaf mine about the same time the leafminer would have. The parasite resembles the leafminer pupa in size and color, but it has a larger head and eyes, and it is flat and naked in the leafmine, whereas leafminer pupae are inside a silk cocoon. Although adult parasites are very small, they are easy to spot if populations are abundant because they fly in groups that hover near infested trees. Organically Acceptable Methods Biological control and sprays of the Entrust formulation of spinosad are the primary means of controlling leafminers in an organically certified crop. Monitoring and Treatment Decisions To determine treatment needs, monitor both the number of sap-feeding mines and parasitization levels of the tissue-feeding stage. First generation larvae normally do not require treatment in California. It is only necessary to monitor parasitism levels of this generation in April. Collect 50 mines with tissue-feeding larvae and examine the larvae for parasites. Sample again in May as soon as sap-feeding mines appear. Randomly collect four leaves from 25 trees. Use the parasitization rate from the first generation sample in conjunction with the number of sap-feeding mines in the current generation to make a treatment decision. Treat if leaves average more than five mines per leaf, or if two or more mines per leaf were present and less than 10% of the first generation was parasitized. If more than 10% of the first generation was parasitized, delay treatment and reevaluate the level of parasites as soon as the current generation reaches the tissue-feeding stage. At this time, examine leafminer larvae in 50 mines for the presence of parasites. To determine if treatment is necessary for the third generation, sample sap-feeding larvae as soon as they appear in July. Collect four leaves from 25 trees. Treat if the leaves are averaging more than five mines



per leaf or if parasitization was less than 30% when parasite levels were reevaluated in the previous sample. Generally, treatment is not recommended for fourth generation larvae unless parasite levels are low or sap-feeding mines exceed an average of five per leaf. Leafminer pheromone traps are available and can be used to monitor flights of this pest. Although no correlation has been developed between number of moths trapped and the occurrence of leaf mines, the traps can help pinpoint the start of the different generations.




When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. SPRING A. ABAMECTIN* (Agri-Mek) 0.15EC 10 fl oz 2.5 fl oz 12 28 MODE OF ACTION GROUP NUMBER1: 6 COMMENTS: Use with an adjuvant. A narrow-spectrum preventive material that is best used in

orchards that have a history of problems with leafminers. Apply at same time as first codling moth treatment.

B. PYRIPROXYFEN (Esteem) 0.86EC Label rates 12 45 (Seize) 35WP Label rates 12 45 MODE OF ACTION GROUP NUMBER1: 7C COMMENTS: Apply a treatment when traps indicate the moth flight is peaking. Do not exceed 2

applications/growing season. C. SPINOSAD (Entrust)# 2–3 oz 0.5–0.75 oz 4 7 (Success) 4–10 fl oz 1.3–3.3 fl oz 4 7 MODE OF ACTION GROUP NUMBER1: 5 COMMENTS: A narrow-spectrum material that is effective against mild populations. Use with emulsi-

fied crop oil or a methylated crop oil and organosilicone combination. SECOND AND THIRD GENERATION A. SPINOSAD (Entrust)# 2–3 oz 0.5–0.75 oz 4 7 (Success) 4–10 fl oz 1.3–3.3 fl oz 4 7 MODE OF ACTION GROUP NUMBER1: 5 COMMENTS: Apply at the very beginning of the second or third generation. A narrow-spectrum

material that is effective against mild populations. Use with emulsified crop oil or a methylated crop oil and organosilicone combination.

B. PYRIPROXYFEN (Seize) 35WP Label rates 12 45 (Esteem) 0.86EC Label rates 12 45 MODE OF ACTION GROUP NUMBER1: 7C COMMENTS: Apply a treatment when traps indicate the moth flight is peaking. Do not exceed 2

applications/growing season. C. NEEM OIL# (Trilogy) 1% 4 0 MODE OF ACTION: Unknown. A botanical insecticide.






D. OXAMYL* (Vydate) L — 0.5 pt 48 14 MODE OF ACTION GROUP NUMBER1: 1A COMMENTS: Apply at least 30 days after bloom or thinning may occur. ** For dilute application, rate is per 100 gal water to be applied in 300-500 gal water/acre, according to label; for

concentrate applications, use 80-100 gal water/acre or lower if the label allows. + Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area

can be safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.

* Permit required from county agricultural commissioner for purchase or use. — Not recommended or not on label. 1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-

action Group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a Group number of 1B; chemicals with a 1B Group number should be alternated with chemicals that have a Group number other than 1B. Mode of action Group numbers are assigned by IRAC (Insecti-cide Resistance Action Committee). For additional information, see their Web site at http://www.irac-online.org/.


Lygus Bugs (3/09) 34 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

LYGUS BUGS (3/09) Scientific Names: Lygus hesperus and Lygus elisus DESCRIPTION OF THE PESTS Lygus bugs vary in color from pale green to yellowish brown with reddish brown to black markings, but can be distinguished by a prominent triangle in the center of the back. The lygus bug adult is about 0.25 inch long and 0.1 inch wide, flattened on the back. Nymphs resemble adults, but are smaller and do not have wings. DAMAGE Lygus bug damage may occur in all major apple districts and sometimes is severe. Lygus attack is more frequent in orchards that have a permanent cover crop and in orchards adjacent to crops or vegetation that host lygus. Lygus bugs may feed on developing flower buds early in spring, causing the buds to exude gum and shrivel up. Usually this damage is not serious unless a very heavy infestation is present. Lygus cause their most serious damage by feeding directly on fruit. Midseason feeding results in round pits, and late-season feeding causes irregularly-shaped depressions that are similar to stink bug damage. MANAGEMENT The potential for a lygus bug population to cause damage is difficult to assess. Lygus bugs may be present in substantial numbers in the orchard and cause no damage; however, they can often cause damage and may attack fruit at any time from petal fall to harvest. Annual preventive treatments are costly and subject to failure because lygus bugs have been quick to develop resistance to chemicals. In orchards with a history of lygus damage, monitor fruit at least biweekly between petal fall and harvest to assess need for treatment. Biological Control The role of predators and parasites in controlling lygus in orchards has not been investigated, but in cotton and strawberries, beneficials have been shown to be helpful. Cultural Control Eliminate or suppress weed host plants before fruit forms on trees and thereafter throughout the growing season to minimize lygus populations. Yellow starthistle, Russian thistle, tarweed, sweet clover, wild mustard, lambsquarters, pigweed, shepherd's-purse, wild radish, and vetch are important hosts. Do not mow cover crops or weeds when lygus bugs are present or they will move into the trees. Organically Acceptable Methods Cultural and biological control are organically acceptable. Monitoring and Treatment Decisions After fruit has formed, sample the cover crop with a sweep net to determine if lygus bugs are present in the orchard. If they are, or if an orchard has had a history of lygus injury, take fruit samples at least every 2 weeks starting soon after petal fall and continue until harvest. Lygus bugs may be present in the orchard but not feeding on the fruit, so you need to check the fruit for damage. Examine a minimum of 100 fruits from trees throughout the block. Because lygus damage is often spotty in distribution, check each block thoroughly. Lygus may migrate into the orchard at any time during the growing season and damage frequently appears first along orchard borders. One damaged apple in 100 is significant for concern and calls for further sampling and evaluation of control needs. When sampling fruit for other pests, also look for the presence of lygus bugs on fruit or in the trees to determine if they are still present in the orchard. Especially be on the lookout for lygus when weeds start to dry up. Because the bugs move quickly and may be difficult to see, the number seen will depend on the skill of the observer. When lygus are migrating into an orchard, periodic spraying of border trees will hold down numbers and reduce damage.


Lygus Bugs (3/09) 35 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html




When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. A. ACETAMIPRID (Assail) 3.4 oz 0.85 oz 12 7 MODE OF ACTION GROUP NUMBER1: 4A COMMENTS: Do not make more than 4 applications/season. Do not exceed 13.5 oz/acre/crop. Repeat

applications of any neonicotinoid insecticide (acetamiprid-Assail; imidacloprid- Provado; and thiacloprid-Calypso) can lead to resistance to all neonicotinoids. Alternate neonicotinoids with an insecticide that has a different mode of action to help delay the development of resistance.

B. IMIDACLOPRID (Provado) 1.6F 8 fl oz 2 fl oz 12 7 MODE OF ACTION GROUP NUMBER1: 4A COMMENTS: Repeat applications of any neonicotinoid insecticide (acetamiprid-Assail; imidacloprid- Provado;

and thiacloprid-Calypso) can lead to resistance to all neonicotinoids. Alternate neonicotinoids with an insecti-cide that has a different mode of action to help delay the development of resistance.

C. DIMETHOATE Label rates 48 28 MODE OF ACTION GROUP NUMBER1: 1B D. FORMETANATE HYDROCHLORIDE (Carzol) SP 1 lb 4 oz 16 days 0 MODE OF ACTION GROUP NUMBER1: 1A COMMENTS: Do not apply more than 1.25 lb/acre/season. Do not apply after petal fall. See label for second

application restrictions. ** For dilute application, rate is per 100 gal water to be applied in 300-500 gal water/acre, according to label; for concentrate



1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action Group number more than twice per season to help prevent the development of resistance. For example, the organophos-phates have a Group number of 1B; chemicals with a 1B Group number should be alternated with chemicals that have a Group number other than 1B. Mode of action Group numbers are assigned by IRAC (Insecticide Resistance Action Commit-tee). For additional information, see their Web site at http://www.irac-online.org/.


Obliquebanded Leafroller (3/09) 36 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

OBLIQUEBANDED LEAFROLLER (3/09) Scientific Name: Choristoneura rosaceana DESCRIPTION OF THE PEST Obliquebanded leafroller overwinter as third instar larvae under bud scales. Larvae are yellowish green with brown to black heads. As they mature, larvae construct tubular shelters from a single leaf. There are two generations a year. Periodically, localized infestations of obliquebanded leafroller occur and the larvae of the summer generation can cause serious damage in July and August. Obliquebanded leafroller is rarely a pest in Central Coast orchards. DAMAGE Larvae feed on flower parts and on fruit early in the season, causing deep depressions that eventually become rough and russeted by harvest. Damage from the summer generation is usually more serious and results in superficial skin tunnels or small holes near the stem portion of the fruit. MANAGEMENT Obliquebanded leafroller can occur in orchards in spring and summer. Summer damage is most com-monly seen in orchards where a switch is made to the use of highly selective materials (including mating disruption) against codling moth that do not control obliquebanded leafrollers. Biological Control The parasitic wasp Macrocentrus iridescens has been observed attacking obliquebanded leafroller larvae in the Central Valley and in Central Coast and North Coast apple orchards. Organically Acceptable Methods Sprays of Bacillus thuringiensis and the Entrust formulation of spinosad are organically acceptable. Monitoring and Treatment Decisions The best time to treat obliquebanded leafrollers is in spring, around pink bud, before the larvae are shel-tered under leaves and between fruit clusters. Apply materials before bees are placed in orchards or after they are removed. Control overwintering larvae with either a delayed dormant application of oil and insecticide or a bloom application. If orchards have experienced damage from this pest in previous years or if leafrollers were observed in spring, also monitor the summer generation. Take fruit and leaf cluster samples at pink bud and in July and August. Tentative thresholds are two or more live larvae in a 100 fruit cluster sample in spring, and four or more in summer.




When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. DELAYED DORMANT A. NARROW RANGE OIL 4 gal 1.5 gal 4 0 MODE OF ACTION GROUP NUMBER1:Improves translaminar movement and insecticide persistence. . . . PLUS . . . CHLORPYRIFOS* (Lorsban) 4EC Label rates 4 days 0 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Avoid drift and runoff into surface waters or choose alternative materials. Chlorpyrifos has been

found in surface waters at levels that violate federal and state water quality standards.


Obliquebanded Leafroller (3/09) 37 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html




BLOOM A. SPINOSAD (Entrust)# 2–3 oz 0.5–0.75 oz 4 7 (Success) 6–10 fl oz 2–3.3 fl oz 4 7 MODE OF ACTION GROUP NUMBER1: 5 COMMENTS: Most effective when applied at petal fall. To prevent the development of resistance to this

product, rotate to a material with a different mode of action after treating two consecutive generations. Do not apply more than 3 sprays/season directed at leafrollers. Do not apply more than 9 oz/acre/crop of Entrust or 29 fl oz of Success/acre/crop.

B. BACILLUS THURINGIENSIS ssp. KURSTAKI# (various products) Label rates — 4 0 MODE OF ACTION GROUP NUMBER1: 11.B2 COMMENTS: Least harmful to beneficials. Bt is a stomach poison and must be consumed by the leafroller;

therefore it is most effective when applied during warm, dry weather when larvae are actively feeding. Most effective against young larvae. Requires more than 1 treatment; apply second application 7–10 days after first.

C. METHOXYFENOZIDE (Intrepid) 2F 16 fl oz — 4 14 MODE OF ACTION GROUP NUMBER1: 18A COMMENTS: Functions both as an ovicide (when applied to eggs and when eggs are laid on residues) and as a

larvicide (must be ingested to be effective). For each generation, begin applications at early egg hatch before webbing and sheltering begin. Make a second application in 10–14 days. Spray coverage is extremely important. Ground application should use 200 gal water/acre with a sprayer speed of 1.5 mph. The addition of a spray adjuvant is recommended to enhance spray coverage.

D. CHLORANTRANILIPROLE (Altacor) 3–4.5 oz — 4 14 MODE OF ACTION GROUP NUMBER1: 28 COMMENTS: Do not apply dilute applications of more than 200 gal/acre; use 100–150 gal/acre for best results. E. SPINETORAM (Delegate) WG 4.5–7 oz — 4 7 MODE OF ACTION GROUP NUMBER1: 5 ** For dilute application, rate is per 100 gal water to be applied in 300–500 gal water/acre, according to label; for concentrate




Group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a Group number of 1B; chemicals with a 1B Group number should be alternated with chemicals that have a Group number other than 1B. Mode of action Group numbers are assigned by IRAC (Insecticide Resistance Action Committee). For additional information, see their Web site at http://www.irac-online.org/.


Omnivorous Leafroller (3/09) 38 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

OMNIVOROUS LEAFROLLER (3/09) Scientific Name: Platynota stultana DESCRIPTION OF THE PEST Omnivorous leafroller larvae are light-colored caterpillars with dark brown or black heads. When mature, they are about 0.6 inch (1.5 cm) long and have two slightly raised, oblong, whitish spots on the upper surface of each abdominal segment. Abdominal segments may have a greenish brown tinge. Larvae pupate inside a webbed shelter. Adults of the overwintering generation emerge in March. They are small, dark brown moths, 0.38 to 0.5 inch (9-12 mm) long with a dark band on the wing and a long snout. Eggs are laid in overlapping rows that resemble fish scales. The first generation of eggs usually is laid on weed hosts, and adults from this generation emerge in May or June to lay eggs in orchards on leaves and fruit. Larvae have the characteristic behavior of wriggling backward when disturbed and dropping from a silk thread attached to the leaf or fruit surface. This pest has two to four generations per year depending on climatic conditions. Omnivorous leafrollers are more common in interior valleys and southern California mountain orchards, especially those next to vineyards, than in orchards in coastal areas or at higher elevations of the Sierra Foothills. DAMAGE Omnivorous leafroller larvae often web leaves into rolled protective shelters while feeding. They feed on leaves and on the surface of fruit, sometimes webbing one or more leaves to the fruit for protection. They chew shallow holes or grooves in the fruit surface, often near the stem end. The damage is similar to that caused by orange tortrix. Larvae feed where fruit are touching, so entire clusters can be damaged. MANAGEMENT Omnivorous leafrollers commonly develop on host plants outside the orchard and move into the orchard in early summer. Infestations often are spotty, making monitoring difficult. Throughout the season, watch for leafrollers when monitoring other pests. Biological Control A number of parasites, including species of Macrocentrus, Cotesia (Apanteles), and Exochus, attack omnivorous leafroller larvae. General predators such as lacewings, Phytocoris, assassin bugs, and minute pirate bugs may feed on eggs and larvae. Preservation of natural enemy populations is an important part of keeping leafroller numbers low. Use selective materials that are least disruptive of biological control when treating other pests. Cultural Control Remove fruit mummies and destroy both the fruit and potential overwintering weed hosts, such as horseweed, common lambsquarters, little mallow, curly dock, and legumes, by clean cultivation. Organically Acceptable Methods Biological and cultural control along with applications of Bacillus thuringiensis and the Entrust formula-tion of spinosad are organically acceptable. Monitoring and Treatment Decisions Begin monitoring by placing pheromone monitoring traps in the orchard by mid-February in the San Joaquin Valley to establish the biofix for the first flight; biofix is the first night moths are consistently caught in traps over the period of several nights. First generation omnivorous leafrollers are most likely to appear on weeds or cover crop; treatments for this first brood are probably not necessary and are likely to be ineffective. From the first biofix, accumulate degree-days (DD) to estimate what the onset of the second flight will occur. Use a lower threshold of 48°F and an upper threshold of 87°F. (For assistance in calculating degree-days, see "Degree-days" on the UC IPM Web site at http://www.ipm.ucdavis.edu). It takes about 1168 DD for omnivorous leafroller to develop from egg to adult. As the start of the second flight nears, be sure to have fresh trap liners and lures in place. When the second flight biofix is deter-mined by trap catches, begin accumulating degree-days. Research in the central San Joaquin Valley indicates that the optimum single treatment timing is between 700 and 900 DD after the start of the flight. Monitor the fruit closely for signs of damage. No treatment threshold values are available.


Omnivorous Leafroller (3/09) 39 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html




When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. A. SPINOSAD (Entrust)# 2–3 oz 0.5–0.75 oz 4 7 (Success) 6–10 fl oz 2–3.3 fl oz 4 7 MODE OF ACTION GROUP NUMBER1: 5 COMMENTS: To prevent the development of resistance to this product, rotate to a material with a different

mode of action after treating two consecutive generations. Do not apply more than 3 sprays/season directed at leafrollers. Do not apply more than 9 oz/acre/crop of Entrust or 29 fl oz of Success/acre/crop.

B. BACILLUS THURINGIENSIS ssp. KURSTAKI# (various products) Label rates — 4 0 MODE OF ACTION GROUP NUMBER1: 11.B2 COMMENTS: Least harmful to beneficials. Bt is a stomach poison and must be consumed by the leafroller;


C. METHOXYFENOZIDE (Intrepid) 2F 16 fl oz — 4 14 MODE OF ACTION GROUP NUMBER1: 11.B2 COMMENTS: Functions both as an ovicide (when applied to eggs and when eggs are laid on residues) and

as a larvicide (must be ingested to be effective). For each generation, begin applications at early egg hatch before webbing and sheltering begin. Make a second application in 10–14 days. Spray coverage is extremely important. Ground application should use 200 gal water/acre with a sprayer speed of 1.5 mph. The addition of a spray adjuvant is recommended to enhance spray coverage.



E. SPINETORAM (Delegate) WG 4.5–7 oz — 4 7 MODE OF ACTION GROUP NUMBER1: 5 ** For dilute application, rate is per 100 gal water to be applied in 300-500 gal water/acre, according to label; for concentrate

applications, use 80-100 gal water/acre or lower if the label allows. + Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can

be safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.

# Acceptable for use on organically grown produce. — Not recommended or not on label. 1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action



Orange Tortrix (3/09) 40 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

ORANGE TORTRIX (3/09) Scientific Name: Argyrotaenia franciscana (formerly A. citrana) DESCRIPTION OF THE PEST Orange tortrix, also called apple skinworm, is a pest in California coastal areas. The moths are 0.5 inch long with tan to rusty brown forewings. The fully grown larvae are about 0.5 inch long, straw colored to green, with light brown heads. They are active and quickly wiggle backwards when disturbed, dropping to the ground or spinning down a silken thread. DAMAGE Orange tortrix is an occasional pest in apple orchards. The principal damage caused by orange tortrix larvae is feeding on the surface of fruit, where they leave shallow, irregular scars. Generally they feed within a fruit cluster; occasionally they tie a leaf to the fruit's surface and feed under it. MANAGEMENT Orange tortrix is frequently controlled by parasites, especially in warm years when high temperatures slow its development. In cool years, higher populations occur, and natural enemies may not be able to hold populations below economically damaging levels; additional control measures may be needed. Biological Control Several parasites and predators attack orange tortrix. Two parasitic wasps, Apanteles aristolilae and Exochus sp., are the most common. Hormius basalis, an external parasite, also occurs. Brown lacewing, Hemerobius pacificus, is a general feeder on orange tortrix. Cultural Control Thin fruit to one or two fruit per cluster to reduce available habitat and to increase exposure of larvae to parasites, predators, and insecticides. Remove and dispose of mummy fruit to reduce overwintering orange tortrix. Orange tortrix feeds on many weeds found in orchards, such as mustard. Plant low-growing grass cover crops to reduce overwintering hosts of orange tortrix. Organically Acceptable Methods While rarely a significant pest in organic orchards, biological and cultural controls and sprays of Bacillus thuringiensis and the Entrust formulation of spinosad are organically acceptable methods for pest control. Monitoring and Treatment Decisions Usually orange tortrix does not appear in apple trees until June when eggs from the first summer generation are laid. Sample trees for larvae once a month in June, July, and August; take the first sample no later than mid-June. Examine 10 trees of each variety in each block for 4 minutes each. Each larva found, whether orange tortrix, apple pandemis, or eyespotted bud moth. Correlates to about 1% fruit damage at harvest. Common name (trade name)



When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. A. BACILLUS THURINGIENSIS ssp. KURSTAKI# (various products) Label rates — 4 0 MODE OF ACTION GROUP NUMBER1: 11.B2 COMMENTS: Least harmful to beneficials. Bt is a stomach poison and must be consumed by the leafroller;



Orange Tortrix (3/09) 41 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html




B. SPINOSAD (Entrust)# 2–3 oz 0.5–0.75 oz 4 7 (Success) 6–10 fl oz 2–3.3 fl oz 4 7 MODE OF ACTION GROUP NUMBER1: 5 COMMENTS: To prevent the development of resistance to this product, rotate to a material with a different

mode of action after treating two consecutive generations. Do not apply more than 3 sprays/season directed at leafrollers. Do not apply more than 9 oz/acre/crop of Entrust or 29 fl oz of Success/acre/crop.


a larvicide (must be ingested to be effective). For each generation, begin applications at early egg hatch before webbing and sheltering begin. Make a second application in 10–14 days. Spray coverage is extremely important. Ground application should use 200 gal water/acre with a sprayer speed of 1.5 mph. The addition of a spray adjuvant is recommended to enhance spray coverage.



E. SPINETORAM (Delegate) WG 4.5–7 oz — 4 7 MODE OF ACTION GROUP NUMBER1: 5 ** For dilute application, rate is per 100 gal water to be applied in 300–500 gal water/acre, according to label; for concentrate



# Acceptable for use on organically grown produce. — Not recommended or not on label. 1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action



Pacific Flatheaded Borer (3/09) 42 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

PACIFIC FLATHEADED BORER (3/09) Scientific Name: Chrysobothris mali DESCRIPTION OF THE PEST Pacific flatheaded borer adults are generally present in May and June. When spring months are warm, they may be seen as early as March or early April. The adult beetle is about 0.4 inch long with a dark bronze body and coppery spots on the wing covers. A fully grown larva is light-colored, with a promi-nent, flat enlargement of the body just behind the head. There is one generation each year. DAMAGE Pacific flatheaded borers are attracted to diseased or injured limbs, such as those affected by sunburn, scale insects, bacterial canker, or major pruning cuts. The beetles lay eggs in the injured area. Eggs hatch and the larvae excavate large caverns just beneath the bark and bore tunnels deep into the heartwood of the tree. Excavations are usually filled with finely powdered sawdust. Injury by this borer will cause the sap to flow, and the affected area will appear as a wet spot on the bark. Later, these areas may crack and expose the mines. Feeding by Pacific flatheaded borers may cause a portion of the bark on older trees to die, or it may girdle and kill young trees. This borer can be particularly damaging to new grafts in established orchards. MANAGEMENT Flatheaded borers often invade sunburned areas on the trunk of newly planted trees. At planting time, wrap or paint the tree trunk above and 1 inch below the soil line with white, water-based paint or whitewash to protect the trunk from sunburn and flatheaded borer invasions. In older trees the best way to avoid infestations is to keep the trees sound and vigorous. Prune out all badly infested wood and burn or remove it from the orchard before the growing season starts. Spraying for this insect is not recom-mended.


Rosy Apple Aphid (1/11) 43 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

ROSY APPLE APHID (1/11) Scientific Name: Dysaphis plantaginea DESCRIPTION OF THE PEST Newly hatched rosy apple aphids are dark green and are found on new growth in early spring. Mature rosy apple aphids, clustering in curled leaves or on young fruits in spring, are purplish and covered with a waxy, powdery bloom. Winged forms develop on apple trees in late spring and migrate to plantain, where they are found in summer. In fall, winged forms develop and migrate back to the apple trees. Overwintering eggs are laid on fruit spurs and shoots of the apple trees; they are shiny, black, and elongated. DAMAGE This is potentially the most damaging aphid species on apples. Rosy apple aphids cluster on leaves of fruit spurs and growing shoots where they cause severe leaf curling. Fruits on heavily infested fruit spurs fail to properly develop and become misshapen. MANAGEMENT Rosy apple aphid numbers vary considerably from year to year; this aphid is not a pest every year. Like many aphids, rosy apple aphid spends part of the growing season on alternate host plants. The most common host is buckhorn plantain, Plantago lanceolata, also known as ribgrass. Other hosts are P. major and P. rugelii. Do not allow these weeds to grow in your cover crop. These species often become a problem when you mow rather than cultivate. Monitor for eggs during the dormant season to determine need for treatment. Biological Control There are many natural enemies that feed on rosy apple aphids; however, fruit size may be reduced before natural enemies bring the aphids under control. Among the important predators are lady beetles, green lacewings, brown lacewings, syrphid fly larvae, and soldier beetles. Inseason sprays (even soap sprays) applied to control rosy apple aphid can kill natural enemies, allowing rosy apple aphid popula-tions to increase. Organically Acceptable Methods Biological control, approved narrow range oil sprays, and the use of azadirachtin (Neemix) are organical-ly acceptable. Monitoring and Treatment Decisions During the dormant season collect 25 to 100 fruit spurs from various parts of trees throughout the block. Using a hand lens, examine the spurs for rosy apple aphid eggs. This can be done in conjunction with the dormant European red mite sample. Although difficult to detect, if any eggs are found, a dormant treatment is required because aphid colonies may quickly spread over the tree. Treat nonbearing trees to prevent stunting of terminal shoots. Because overwintering eggs are located on the bark, delayed dormant application will greatly reduce populations. Young trees need to be treated when terminals are infested; mature trees can tolerate more damage. Codling moth sprays should be chosen with aphid control in mind. Common name (trade name)



When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. DORMANT AND DELAYED DORMANT A. DORMANT FLOWABLE EMULSION OIL 8 gal 4 gal 4 0 MODE OF ACTION: Contact including smothering and barrier effects. COMMENTS: Organic growers should apply dormant flowable emulsion during delayed dormant to silver

tip stage to get any control of rosy apple aphid.






B. NARROW RANGE OIL Label rates Label rates see label 0 MODE OF ACTION: Improves translaminar movement and insecticide persistence. . . . PLUS . . . CHLORPYRIFOS* (Lorsban) 4EC Label rates 4 days 0 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: This is the best material to use if apple pandemis is also present. Follow restrictions on

supplemental label. Avoid drift and runoff into surface waters or choose alternative materials. Chlorpyrifos has been found in surface waters at levels that violate federal and state water quality standards.

. . . or . . . DIAZINON* 50WP 4 lb 1 lb 4 days 21 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Avoid drift and runoff into surface waters or choose alternative materials. Diazinon has been

found in surface waters at levels that violate federal and state water quality standards. SPRING FOLIAGE SPRAY A. SPIROTETRAMAT (Movento) 6–9 fl oz — 24 7 MODE OF ACTION GROUP NUMBER1: 23 COMMENTS: Do not apply until after petal fall. Allow 14 days between applications. Maximum is 25 fl

oz/acre (0.4 lb a.i./acre)/crop/season. B. IMIDACLOPRID (Provado) 1.6F 8 fl oz 2 fl oz 12 7 MODE OF ACTION GROUP NUMBER1: 4A COMMENTS: Apply before leaf curling starts. Repeat applications of any neonicotinoid insecticide (acetam-

iprid-Assail; imidacloprid-Provado; thiamethoxam –Actara) can lead to resistance to all neonicotinoids. Alternate neonicotinoids with an insecticide that has a different mode of action Group number to help delay the development of resistance. To help prevent development of resistance, do not use for both codling moth and aphid control.

C. ACETAMIPRID (Assail) 70 WP 1.1–1.7 oz — 12 7 MODE OF ACTION GROUP NUMBER1: 4A COMMENTS: May cause outbreaks of mites, especially in orchards with chronic mite problems; addition of

1% oil (volume by volume) and limiting applications to a single application may help mitigate mite problems. Repeat applications of any neonicotinoid insecticide (acetamiprid-Assail; imidacloprid- Provado; and thiacloprid-Calypso) can lead to resistance to all neonicotinoids. Alternate neonicotinoids with an insecticide that has a different mode of action to help delay the development of resistance. To help prevent development of resistance, do not use for both codling moth and aphid control.

D. THIACLOPRID (Calypso) 2–4 fl oz 0.5–1 fl oz 12 30 MODE OF ACTION GROUP NUMBER1: 4A COMMENTS: Most effective at early leafing. May cause outbreaks of mites, especially in orchards with

chronic mite problems; addition of 1% oil (volume by volume) and limiting applications to a single applica-tion may help mitigate mite problems. Otherwise, to help prevent the development of insect resistance, limit applications to one generation/year. Repeat applications of any neonicotinoid insecticide (acetamiprid-Assail; imidacloprid- Provado; and thiacloprid-Calypso) can lead to resistance to all neonicotinoids. Alternate neonicotinoids with an insecticide that has a different mode of action to help delay the development of resistance. To help prevent development of resistance, do not use for both codling moth and aphid control.

E. DIAZINON* 50WP 4 lb 1 lb 4 days 21 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Foliage treatments are important for young trees with severe infestations. Applications made

during the foliage season are very disruptive to beneficials. Codling moth sprays will normally control aphids. Avoid drift and tailwater runoff into surface waters.






F. NARROW RANGE OIL# (JMS Stylet Oil, Omni, etc.) Label rates see label 0 MODE OF ACTION: Contact including smothering and barrier effect. COMMENTS: Apply as soon as colonies are found and reapply at 7- to 10-day intervals as long as active

colonies are found. G. NARROW RANGE OIL# (JMS Stylet Oil, Omni, etc.) Label rates see label 0 MODE OF ACTION: Improves translaminar movement and insecticide persistence. . . . PLUS . . . AZADIRACHTIN# (Neemix) Label rates 12 0 MODE OF ACTION GROUP NUMBER1: 18B COMMENTS: Apply as soon as colonies are found and reapply at 7- to 10-day intervals as long as active

colonies are found. Azadirachtin without oil is not effective in controlling this pest. ** For dilute application, rate is per 100 gal water to be applied in 300–500 gal water/acre, according to label; for concentrate






San Jose Scale (3/09) 46 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

SAN JOSE SCALE (3/09) Scientific Name: Diaspidiotus (= Quadraspidiotus) perniciosus DESCRIPTION OF THE PEST Female San Jose scales give birth to living young that emerge from under the edge of the scale covering. These tiny yellow crawlers wander in a random fashion until they find a suitable place to settle. Immedi-ately upon settling, the crawlers insert their mouthparts into the host plant and begin feeding and secreting a white waxy material (white cap stage); eventually the waxy covering turns black and is known as the black cap stage. Later the covers turn various shades from gray to black. San Jose scales overwinter predominantly in the black cap stage, although in mild years some adult mated females may also survive. In late January, these nymphs resume their growth. Immature male and female scales are indistinguishable until the first molt. At this time, the male scale covering begins to elongate, while the female's remain circular. Males molt a total of four times. Following the final molt, adult male scales emerge from the scale covering as tiny, yellow winged insects. They mate with the females who remain under the scale covering. After about 2 months, crawlers begin to emerge from the females, usually in April; peak emergence is generally in early May. There are usually four generations a year. Summer generations overlap and crawlers are present throughout summer and fall. DAMAGE If heavy scale infestations are left unchecked, trees may be seriously damaged, resulting in reduced vigor, thin foliage, cracked or dying branches, and the eventual death of the tree. Young trees may be killed before fruiting. Infested fruit develop a reddish purple ring surrounding each spot where a scale settles. MANAGEMENT San Jose scale is the most common and the most damaging of the scales found in apple orchards. Dormant season treatments are the key to controlling this pest. The only other effective treatment time is in May. Natural enemies can contribute significantly to control when not disrupted by insecticides. Biological Control Natural enemies that feed on San Jose scale include two predaceous beetles: the twicestabbed lady beetle, Chilocorus orbus, and another small beetle, Cybocephalus californicus. A number of small chalcid and aphelinid wasps parasitize this scale. These predators and parasites may be helpful in reducing scale populations, but insecticides used during the growing season for other pests can disrupt this natural control and scale populations increase rapidly. Organically Acceptable Methods Biological control and approved oil sprays are organically acceptable methods, but San Jose scale is rarely a pest in organic orchards. Monitoring and Treatment Decisions Monitor for San Jose scale during the dormant period by checking prunings to make sure scale hasn't developed in tree tops. Also check fruit at harvest for the presence of scale. Due to the damage potential of this pest, annual dormant sprays are recommended in most areas. Oil sprays work the best on the black cap stage, so apply them in early January. Control heavy populations of San Jose scale by applying an insecticide plus oil spray during the delayed dormant period. If inadequate control is achieved with the dormant spray, treatments are also effective when applied soon after the emergence of the crawlers in May. Use pheromone traps in March to monitor for male San Jose scale flights and double-sided sticky tape for monitoring crawlers in April and May. Time a treatment, using a 51°F lower threshold and 90°F upper threshold, for 600 to 700 DD after the beginning of the male flight or 200 degree-days after crawler emergence begins.


San Jose Scale (3/09) 47 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html




When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. DORMANT A. NARROW RANGE OIL# 6 gal 1.5 gal 4 0 MODE OF ACTION: Contact including smothering and barrier effects. COMMENTS: Check with certifier to determine which products are organically acceptable. DELAYED DORMANT A. NARROW RANGE OIL 6 gal 1.5 gal 4 0 MODE OF ACTION: Improves translaminar movement and insecticide persistence. . . . PLUS . . . PYRIPROXYFEN (Esteem) 0.86EC Label rates 12 45 (Seize) 35WP 4–5 oz — 12 45 MODE OF ACTION GROUP NUMBER1: 7C COMMENTS: Apply from delayed dormancy through pink bud. . . . or . . . CHLORPYRIFOS* (Lorsban) 4EC Label rates 4 days 0 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Avoid drift and tailwater runoff into surface waters or choose alternative materials. Chlorpyri-

fos has been found in surface waters at levels that violate federal and state water quality standards. . . . or . . . ESFENVALERATE (Asana XL) Label rates 12 21 MODE OF ACTION GROUP NUMBER1: 3 B. METHIDATHION* (Supracide) 2EC 6–12 pt 0.75–1.5 pt 3 days 0 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Apply before blossoms open or injury may occur. CRAWLER TREATMENT A. DIAZINON* 50WP 4 lb 0.75–1 lb 4 days 21 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Avoid drift and tailwater runoff into surface waters or choose alternative materials. B. NARROW RANGE OIL# 6 gal 1.5 gal 4 0 MODE OF ACTION: Contact including smothering and barrier effects. Check with certifier to determine

which products are organically acceptable. ** For dilute application, rate is per 100 gal water to be applied in 300-500 gal water/acre, according to label; for concentrate






Stink Bugs (3/09) 48 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

STINK BUGS (3/09) Scientific Names: Consperse stink bug: Euschistus conspersus Conchuela: Chlorochroa ligata Redshouldered stink bug: Thyanta pallidovirens DESCRIPTION OF THE PESTS Stink bugs and other plant bugs occur in all of California, but only reach damaging numbers sporadically. Although they may differ in color and size, stink bugs have the same overall shield-shaped body. The consperse stink bug is the most common. Adult consperse stink bugs have gray brown to green bodies with yellow to orange legs and antennae that have darkened tips. The body and legs are covered with small black specks and the undersurface of the body varies from gray to green. Consperse stink bug eggs are laid in clusters on twigs and leaves. They are barrel-shaped, pearly white when first laid, turning pink before hatching. The conchuela is a large black stink bug with a reddish marginal border and a reddish spot in the middle of the back. Redshouldered plant bugs are green or brown stink bugs that may have a red line across the shoulder. DAMAGE Stink bugs damage the crop directly by feeding on fruit. Early season feeding results in dimples or irregularly depressed areas on mature fruit. If the feeding occurs after maturity there is little external evidence other than excrement, which appears as small, brown, tear-shaped drops. Internally, stink bug feeding produces white, pithy areas that turn brown when fruit is peeled. If the spots are the result of stink bug feeding, these pithy areas will be concentrated near the stem end of the fruit. If they resulted from lygus bug feeding, they may be located anywhere on the fruit surface. Adult stink bugs move from tree to tree and can puncture large numbers of fruit. If they are migrating into the orchard, fruits on trees in outside rows will show the most damage. Frequently, damage by these pests is limited to specific areas in the orchard. If the infestation is very heavy, however, the entire crop can be damaged. MANAGEMENT Infestations of stink bugs depend on the type of vegetation in and adjacent to the orchard. Most infesta-tions occur in orchards with ground covers or adjacent to uncultivated areas; stink bugs move to ground covers in orchards when weeds in uncultivated areas dry. Consperse stink bug is rarely a pest in clean-cultivated orchards surrounded by cultivated lands, unless the land is planted in crops stink bugs favor: wheat, tomatoes, berries, alfalfa, or corn. Cultural Control Eliminate weed host plants listed above both within and adjacent to the orchard to minimize stink bug problems. Do not mow cover crops or weeds when stink bugs are present or they will move into the trees. Organically Acceptable Methods Cultural control is organically acceptable. Monitoring and Treatment Decisions Monitor for stink bugs in March or April by inspecting host plants located inside and along borders of sampling blocks. Spend about an hour checking the bases of plants for overwintered adult bugs. Favored host plants are mullein, mustard, and dock. If these are not present, bugs may be found on plantain, milkweed, mallow, morningglory, thistles, vetch, velvetgrass, breadgrass, bushberries, everlasting peas, and other broadleaf plants. If more than five bugs are found during the hour, spray the weeds with an insecticide immediately. Depending on the distribution of the bug population, a spot treatment may be adequate. If two to five bugs are found and bug damage has been experienced previously in the orchard, spraying the weeds might be advisable. If fewer than two bugs are found, resample in 7 to 10 days. Sample for adults or damaged fruit in June and July. Take a 50-tray beating sample for each 20-acre block, taking most of the samples from border trees to locate bugs flying in from adjacent fields. If one or more bugs are collected, inspect fruit for feeding damage. Either examine fruit on the tree for the presence of bugs, excrement, or visible damage, or collect fruit from the lower half of the tree and peel it. If more than three fruits per half hour of inspection show feeding damage, spots of excrement, or active bugs, or there is one damaged fruit per 100 peeled, treatment of trees probably is required to avoid economic loss by end of harvest.


Stink Bugs (3/09) 49 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html




When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. PINK BUD to BLOOM Note: Apply as a thorough, drenching ground spray to cover crop; use 100–300 gal water/acre. A. FENPROPATHRIN* (Danitol) 2.4EC 16–21.33 fl oz 4–5.44 fl oz 24 14 MODE OF ACTION GROUP NUMBER1: 3 COMMENTS: Begin applications when first pest activity is noticed. Use higher rate under severe insect

pressure. B. DIMETHOATE E267 — Label rates 48 28 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Do not apply during bloom. Harmful to beneficial mites. C. FORMETANATE HYDROCHLORIDE (Carzol) SP — 4 oz 16 days 0 MODE OF ACTION GROUP NUMBER1: 1A COMMENTS: Do not apply more than 1.25 lb/acre/season. Do not apply after petal fall. See label for second

application restrictions. D. ENDOSULFAN* (Thionex) 3EC — 1.33 pt 24 30 MODE OF ACTION GROUP NUMBER1: 2A COMMENTS: Do not apply near bodies of water containing fish. Stink bugs may be resistant to endosulfan.

Maximum of 3.5 qt/acre. MAY/JUNE to PREHARVEST Note: Apply to trees A. FENPROPATHRIN* (Danitol) 2.4EC 16–21.33 fl oz 4–5.44 fl oz 24 14 MODE OF ACTION GROUP NUMBER1: 3 COMMENTS: Begin applications when first pest activity is noticed. Use higher rate under severe insect

pressure. Disruptive of natural enemies. B. DIMETHOATE Label rates 48 28 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Harmful to beneficial mites. C. ENDOSULFAN* (Thionex) 50WP 4 lb 1 lb 4 days 30 MODE OF ACTION GROUP NUMBER1: 2A COMMENTS: Do not apply near bodies of water containing fish. Stink bugs may be resistant to endosulfan.

Maximum of 3.5 qt/acre. ** For dilute application, rate is per 100 gal water to be applied in 300-500 gal water/acre, according to label; for concentrate



* Permit required from county agricultural commissioner for purchase or use. — Not recommended or not on label. 1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action



Webspinning Spider Mites (3/09) 50 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

WEBSPINNING SPIDER MITES (3/09) Scientific Names: Twospotted spider mite: Tetranychus urticae Pacific spider mite: Tetranychus pacificus McDaniel spider mite: Tetranychus mcdanieli DESCRIPTION OF THE PESTS Adult female mites are larger and more elongated than European red mites and are green to yellow. Feeding mites have a dark spot on either side of the body that may enlarge to cover most of the body. Overwintering females are orange and hibernate under bark scales on the tree and in trash on the ground. They move up the tree in late March and April, feeding on leaves. Rapid reproduction occurs in hot, dry weather and the infestation peaks in July and August. The tiny, spherical, colorless to straw-colored eggs are distributed over the infested area. DAMAGE Mites feed upon leaves, removing the cell contents and gradually giving leaves a finely stippled appear-ance. Heavy infestations result in severe bronzing of foliage and premature defoliation. Fruits on heavily infested trees fail to color and size properly, and fruit production for the following year may be lowered. MANAGEMENT Webspinning spider mites are typically most abundant during the hot summer months, especially in dusty and water-stressed areas of the orchard. Natural enemies keep spider mites below damaging levels in many orchards. Monitor for mites and their natural enemies from June through August to determine the need for treatment. Resistant Varieties Varieties such as Red Delicious, Golden Delicious, Rome Beauty, and Jonathan are more susceptible to mite injury, while Gravenstein and Yellow Newtown show less evidence of leaf damage from moderate populations. Biological Control The western predatory mite, Galendromus (=Metaseiulus) occidentalis, is an excellent predator of webspin-ning mites. Predator mites have been developed that are resistant to carbaryl and most organophosphates used in apples. One predator to 10 webspinning mites is necessary for the predators to keep control of the pest mites. Use lower rates of miticides to minimize destruction of predators and allow some spider mites to survive. The apple rust mite is an alternative food source for the predator mite. Avoid sprays contain-ing lime sulfur, which will kill rust mites. When alternative food sources are allowed to survive, the predaceous mites can build up large enough numbers to control webspinning mite populations. Cultural Control Grass cover crops and sprinkler irrigation help to minimize dust in orchards. Provide adequate irrigation to avoid water stress. Do not mow the cover crop too short or let it dry, or the mites may move up into the trees. Organically Acceptable Methods Biological and cultural control and the use of resistant varieties are organically acceptable methods. Monitoring and Treatment Decisions From July to August, or if you encounter high mite populations earlier in the season, collect five spur leaves at spaced intervals from one lateral branch located at eye level from each of 20 marked trees that have been established as representative trees in a block. Brush leaves in a mite-brushing machine and count mites but not eggs. Sample every 1 to 3 weeks. Treat when mite populations reach an average of 10 mites per leaf. Count predatory mites along with webspinning mites. If you find one predatory mite per 10 mites, you may not need a miticide application but continue sampling to be sure pest mite populations do not increase. If treatment is required choose materials least disruptive of biological control.


Webspinning Spider Mites (3/09) 51 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html




When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. A. ABAMECTIN* (Agri-Mek) 0.15EC 10–20 oz 2.5–5 oz 12 28 MODE OF ACTION GROUP NUMBER1: 6 COMMENTS: Narrow-spectrum preventive material that can be applied early in the season (from petal fall to

6 weeks later) when mite outbreaks are anticipated. Use with a horticultural spray oil. B. CLOFENTEZINE (Apollo) 50SC 4–8 oz 1–2 oz 12 45 MODE OF ACTION GROUP NUMBER1: 10A COMMENTS: For early and mid-season mite control; easy on natural enemies. C. FENBUTATIN-OXIDE* (Vendex) 50WP 1–2 lb 4–8 oz 48 14 MODE OF ACTION GROUP NUMBER1: 12B COMMENTS: This material appears to be most effective when applied earlier in the season rather than later.

Do not apply more than twice a season in not more than 400 gal water/acre. Do not apply more than 4 lb/acre/year.

D. PYRIDABEN (Nexter) 5.2 oz 3.3 oz 12 25 MODE OF ACTION GROUP NUMBER1: 21 COMMENTS: Can be used later in the season than preceding materials and is easier on beneficials than

dicofol. Do not use less than 100 gal water/acre spray volume. Most effective with use of a silicone spreader. E. ETOXAZOLE (Zeal) 2–3 oz 0.5–0.75 oz 12 28 MODE OF ACTION GROUP NUMBER1: 10B COMMENTS: Preliminary research indicates it has an effect on the reproductive capacity of predatory mites.

Most effective with use of a silicon spreader. F. BIFENAZATE (Acramite) 50WS 1 lb 0.25 lb 12 7 MODE OF ACTION GROUP NUMBER1: 25 COMMENTS: Only one application/crop/year. Most effective with use of a silicon spreader. G. DICOFOL (Kelthane) Label rates 48 7 MODE OF ACTION: UNC COMMENTS: For use on late-season mite outbreaks. This material is harsh on beneficials so its use is best late

in the season when necessary. ** For dilute application, rate is per 100 gal water to be applied in 300–500 gal water/acre, according to label; for concentrate



* Permit required from county agricultural commissioner for purchase or use. 1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action



Western Flower Thrips (12/09) 52 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

WESTERN FLOWER THRIPS (12/09) Scientific Names: Western flower thrips: Frankliniella occidentalis

DESCRIPTION OF THE PESTS Western flower thrips adults are minute insects, about 0.03 inch long, with two pairs of fringed wings. The adult has three color forms that vary in abundance depending on the time of year. There is a pale form that is white and yellow, except for slight brown spots or blemishes on the top of the abdomen; an intermediate color form with an orange thorax and brown abdomen; and a dark form that is dark brown. The intermediate form is present throughout the year, but in spring the dark form predominates while the pale form is most abundant at other times throughout the year.

First-instar nymphs are opaque or light yellow, turning to golden yellow after the first molt. The nymphal stage lasts from 5 to 20 days.

DAMAGE Western flower thrips are attracted to the blossoms of apples as well as orchard cover crops and weeds. The primary damage is from egg-laying punctures in newly formed fruit, which typically occur before petal fall. The egg-laying site develops into tiny russetted spot surrounded by an irregular yellow patch known as a pansy spot (as it resembles the shape of a pansy). Granny Smith and other green varieties as well as Rome Beauty and McIntosh show more damage from this pest. MANAGEMENT Cultural Control Thrips are often attracted to weeds blooming on the orchard floor. To prevent driving thrips into the trees, do not disc the cover crop when trees are in bloom. Open, weedy land adjacent to orchards should be disced as early as possible to prevent thrips development and migration of adults into orchards.

Organically Acceptable Methods Cultural controls and sprays of the Entrust formulation of spinosad are organically acceptable tools.

Monitoring and Management Decisions Inspect for adult western flower thrips at 10% bloom. If several thrips, on the average, can be dislodged onto a sheet of paper by tapping individual flower clusters, a treatment may be needed to prevent damage.

Harvest fruit sample. At harvest, assess program by monitoring fruit in the bins for thrips damage. Sample 200 fruit per bin from 5 bins per orchard (or 20-acre block in large orchards). Common name (trade name)

Amount to use R.E.I.+ (hours)

P.H.I.+ (days)

When choosing a pesticide, consider information relating to impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. A. SPINOSAD (Entrust)# 1 oz/acre 4 7 (Success) 3.5 oz/acre 4 7 MODE OF ACTION GROUP NUMBER1: 5 COMMENTS: Control may be improved by addition of an adjuvant to the spray mixture. Do not apply more

than 29 oz/acre/year of Success or 9 oz/acre/year of Entrust. + Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can

be safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.

# Acceptable for organically grown produce. 1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action



Western Tussock Moth (3/09) 53 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

WESTERN TUSSOCK MOTH (3/09) Scientific Name: Orgyia vetusta DESCRIPTION OF THE PEST Western tussock moth has one generation a year. Wingless females lay 125 to 300 eggs in a single mass on the empty pupal case. Overwintering eggs hatch when spring growth is expanding. Young larvae are black caterpillars with long bristles; mature larvae have numerous red and yellow spots and four median dorsal tufts. DAMAGE A heavy infestation will destroy all spring growth. Larvae take shallow bites out of newly set, young fruit; these injured areas eventually scab over and russet. Infestations are spotty and may be isolated in certain areas of an orchard. MANAGEMENT Western tussock moth is common throughout California, especially in unsprayed orchards. Monitor for egg masses in winter and larvae in spring to determine need for treatment. Organically Acceptable Methods Sprays of Bacillus thuringiensis and the Entrust formulation of spinosad are organically acceptable. Monitoring and Treatment Decisions During winter look for western tussock moth egg masses on props or tree trunks. Monitor during bloom by examining 100 fruit clusters for larvae. Spot treat infested areas in the orchard. Applications made at night during bloom will minimize damage to bees. This insect is usually controlled by sprays for other pests. Common name (trade name)



When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. A. BACILLUS THURINGIENSIS spp. KURSTAKI# (various products) Label rates — 4 0 MODE OF ACTION GROUP NUMBER1: 11.B2 COMMENTS: Least harmful to beneficials. Bt is a stomach poison and must be consumed by the caterpillar;

therefore, it is most effective when applied during warm, dry weather when larvae are actively feeding. Spray during bloom or when monitoring indicates a need. Most effective against young larvae. Requires more than 1 treatment; apply second application 7–10 days after first.

B. SPINOSAD (Entrust)# 2–3 oz 0.5–0.75 oz 4 7 (Success) 6–10 oz 2–3.3 oz 4 7 MODE OF ACTION GROUP NUMBER1: 5 COMMENTS: Apply at petal fall. To prevent the development of resistance to this product rotate to a material

with a different mode of action after treating two consecutive generations. ** For dilute application, rate is per 100 gal water to be applied in 300–500 gal water/acre, according to label; for concentrate






Woolly Apple Aphid (1/11) 54 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

WOOLLY APPLE APHID (1/11) Scientific Name: Eriosoma lanigerum DESCRIPTION OF THE PEST Woolly apple aphids infest roots, trunks, limbs, shoots, and occasionally fruit of apple trees. The bodies of these bark-feeding aphids are completely covered by masses of white, wool-like, waxy materials. This aphid is found in colonies on the aerial portions of the tree and on roots during winter. The nymphs migrate up or down the trunk of infested trees during summer and fall. DAMAGE The main injury to young and mature trees is stunting due to the formation of root galls. If populations are high, honeydew and sooty mold will also be problems, and aphids may enter the calyx end of fruit. MANAGEMENT Woolly apple aphid is found throughout California's apple-growing regions, and it is a major pest in coastal counties. It occasionally infests pyracantha, hawthorn, and pear. Resistant Varieties/Rootstocks Winter Banana is one of the most susceptible varieties to aerial galls. Yellow Newtown fruit frequently has aphids in the calyx end. The Malling series of rootstock numbers 106 and 111 are resistant to this pest. Biological Control Aphelinus mali is a parasite that can completely control aerial colonies. In the absence of this parasite there can be large increases of aerial colonies and woolly aphids may be found in the calyx of the apple. Outbreaks of woolly apple aphid are most common following the use of pyrethroids, which destroys its natural enemies. Organically Acceptable Methods Resistant varieties and rootstocks as well as biological control are organically acceptable methods. Treatment Decisions The delayed dormant application should control woolly apple aphids. A summer application (late July to August) will only be required if the parasites are disrupted. Foliage treatments may be necessary for young trees with severe infestations. Common name (trade name)



When choosing a pesticide, consider information relating to the impact on natural enemies and honey bees and environmental impact. Not all registered pesticides are listed. Always read label of product being used. DELAYED DORMANT (Preferred timing) A. NARROW RANGE OIL Label rates Label rates see label 0 MODE OF ACTION: Improves translaminar movement and insecticide persistence. . . . PLUS . . . CHLORPYRIFOS* (Lorsban) 4EC Label rates 4 0 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Avoid drift and runoff into surface waters or choose alternative materials. Chlorpyrifos has

been found in surface waters at levels that violate federal and state water quality standards. . . . or . . . DIAZINON* 50WP 2–4 lb 0.5–1.0 lb 4 days 21 MODE OF ACTION GROUP NUMBER1: 1B COMMENTS: Avoid drift and runoff into surface waters or choose alternative materials. Diazinon has been

found in surface waters at levels that violate federal and state water quality standards.


Woolly Apple Aphid (1/11) 55 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html




FOLIAGE SPRAY A. SPIROTETRAMAT (Movento) 6–9 fl oz — 24 7 MODE OF ACTION GROUP NUMBER1: 23 COMMENTS: Do not apply until after petal fall. Allow 14 days between applications. Maximum is 25 fl

oz/acre (0.4 lb a.i./acre)/crop/season. B. DIAZINON* 50WP 4 lb 1 lb 4 days 21 MODE OF ACTION: An organophosphate (Group 1B)1 insecticide. COMMENTS: Applications made during the foliage season are very disruptive to beneficials. Avoid drift and

runoff into surface waters or choose alternative materials.

** For dilute application, rate is per 100 gal water to be applied in 300–500 gal water/acre, according to label; for concentrate applications, use 80–100 gal water/acre or lower if the label allows.


* Permit required from county agricultural commissioner for purchase or use. 1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action



Apple Scab (3/09) 56 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

Diseases APPLE SCAB (3/09) Pathogen: Venturia inaequalis SYMPTOMS Superficial, velvety dark-olive-to-black spots on fruits and leaves are the initial symptoms of apple scab. These fruit spots become scablike with age and tissues may become misshapen. COMMENTS ON THE DISEASE The fungus survives in dead leaves on the ground. Primary spores are discharged during spring rains and infect young leaves and fruits during prolonged moisture. Secondary spores may spread disease from established infections on trees. A lack of spring rains in most years reduces its importance in California in the southern Central Valley, but as a rule, this disease requires yearly treatments in coastal and foothill districts. Ornamental crab apples are also hosts. As plant parts mature and the weather gets warmer, susceptibility to this disease decreases, but pinpoint scab can occur during extended periods of moisture during summer. MANAGEMENT The main objective in scab management is the reduction or prevention of primary infections in spring. Extensive primary infections result in poor fruit set and make scab control during the season more difficult. If primary infections are successfully controlled, secondary infections will not be serious. The key to success in scab control is exact timing and full coverage. Wet periods, temperature, and relative humidity are important factors. Because scab control often is part of a combination treatment aimed at other diseases and insect control, choice of materials and timing are also extremely important. A fall foliar fertilizer application of zinc sulfate and urea hastens leaf fall and speeds decomposition of fallen leaves. This in turn reduces the level of overwintering apple scab inoculum. Organically Acceptable Methods Treatments with lime and sulfur, sulfur alone, or with approved fixed copper products are organically acceptable. Monitoring Apple scab outbreaks can be predicted based on temperature and moisture conditions. The table below, derived from research by Mills and La Plante, gives hours needed at various temperatures under con-stantly wet conditions for primary spores (ascospores) to cause infection in spring. This system for forecasting scab and timing sprays has been validated for apple-growing regions in the northern areas of California, but not for the central and southern San Joaquin Valley where temperatures tend to be higher in spring than those in the table.



TABLE 1. Mills and La Plante Table.

HOURS OF WETTING REQUIRED FOR INFECTION Average temperature

(degrees ºF) From primary inoculum (ascospores)

(hours) 78 13 77 11 76 9.5

61–75 9 60 9.5

57–59 10 55–56 11

54 11.5 52–53 12

51 13 50 14 49 14.5 48 15 47 17 46 19 45 20 44 22 43 25 42 30

33–41 * * Not known

How to use the table. Figure the average temperature for the rain period by adding the maximum and the minimum temperatures and dividing by 2. If wet periods are intermittent, total their durations until there is a period of at least 6 hours of continuous dryness. You will need a wetness recorder to do this efficiently. If the dry period is sunny, and drying is quick and thorough, it is assumed that 6 hours after the trees have dried, the danger is passed. If drying is slow, and humidity remains high, then the 6-hour dry period is extended by a safety margin of 3 to 4 hours. Treatment Decisions Unless wetness periods are being monitored as outlined in the section above, apply protective fungicides at regular intervals beginning with green tip. Be sure to monitor wetness periods throughout the spring to insure that trees are adequately protected.

PERIOD OF EFFECTIVENESS1

FUNGICIDE

When used as protectant

(days)

When used as kickback2

(hours) Captan 10 0 Copper 7–10 — Dithane 10 0 Flint 7–10 100 Lime sulfur 5–7 36 Procure 7–10 72 Rally 14 96 Rubigan 14 96 Scala 7–10 — Sovran 7–10 96 Sulfur (micronized) 5–7 0 Topsin M 10 36–48 Vangard 7–10 48 Ziram 7–10 0 — Information not available. 1 Where range of days or hours is given, the difference reflects application rates –higher rates offer longer protection. 2 Eradicant fungicides have systemic action. Some are translocated within the host tissue and are able to kill the scab

fungus up to a certain length of time after infection occurs. This is called the kickback period. Because kickback periods may change, always check the label for the most recent information. Kickback is calculated from the beginning of an infection period, as determined by the Mills and La Plante table.




Amount to Use R.E.I.+ (hours)

P.H.I.+ (days)

The following materials are listed in order of usefulness in an IPM program, taking into account efficacy. When choosing a pesticide, also consider information relating to environmental quality. Not all registered pesticides are listed. Always read label of product being used. A. FENARIMOL (Rubigan) 1EC 9–12 oz/acre 12 30 MODE OF ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3) COMMENTS: Do not apply between popcorn and full bloom. Do not apply more than 84 fl

oz/acre/season. B. MYCLOBUTANIL (Rally) 40WP 1.25–2 oz/100 gal water 24 14 MODE OF ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3) COMMENTS: Apply 400 gal/acre. Do not apply between popcorn and full bloom. During periods

favorable for scab development, use high rate at a 7 day application interval. For postbloom control, can be used in combination with another protectant fungicide. Do not apply more than 5 lb/acre/season or graze or feed cover crops grown in treated areas to livestock. For application by ground equipment only.

C. TRIFLUMIZOLE (Procure) 50WS 2–4 oz/100 gal 12 14 MODE OF ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3) COMMENTS: Do not exceed 16 oz/acre/application. D. TRIFLOXYSTROBIN (Flint) 2–2.5 oz/acre 12 14 MODE OF ACTION GROUP NAME (NUMBER1): Quinone outside inhibitor (11) COMMENTS: Alternate with a sterol inhibitor fungicide. Do not apply more than 2 consecutive applica-

tions before alternating. Do not apply more than 11 fl oz/acre/season. E. PYRIMETHANIL (Scala) SC 7–10 fl oz/acre 12 72 MODE OF ACTION GROUP NAME (NUMBER1): Anilinopyrimidine (9) COMMENTS: Make application on 7 day or longer, depending on disease conditions. Do not apply more

than 40 fl oz product/acre/crop. F. KRESOXIM METHYL (Sovran) 3.2–6.4 oz/acre 12 30 MODE OF ACTION GROUP NAME (NUMBER1): Quinone outside inhibitor (11) COMMENTS: Begin applications at 1/2 inch green or when conditions are conducive to disease devel-

opment. Repeat at 7- to 10-day intervals. Do not apply more than 25.6 oz/acre/season. G. THIOPHANATE METHYL (Topsin-M) 70WP 1–1.5 lb/acre 12 0 MODE OF ACTION GROUP NAME (NUMBER1): Methyl benzimidazole (1) COMMENTS: Apply at 5- to 10-day intervals from green tip through petal fall; continue at 7-to 14-day

intervals as needed. Do not apply more than 4 lb product/acre/season. H. CYPRODINIL (Vangard) WG 3–5 oz/acre 12 72 MODE OF ACTION GROUP NAME (NUMBER1): Anilinopyrimidine (9) COMMENTS: Make applications on a 7- to 10-day interval. At the 3 oz (protectant) rate there is no

kickback period of control, whereas at the 5 oz rate this material has a 48 hour kickback period. I. CAPTAN 50WP 2 lb/100 gal water 4 days 0 MODE OF ACTION GROUP NAME (NUMBER1): Multi-site contact (M4) COMMENTS: Apply 400 gal/acre. Do not apply in combination with, immediately before, or closely

following oil sprays.





P.H.I.+ (days)

J. LIQUID LIME SULFUR# 2 gal/100 gal 48 0 . . . PLUS . . . WETTABLE SULFUR# 4–5 lb/100 gal 24 0 MODE OF ACTION GROUP NAME (NUMBER1): Multi-site contact (M2) COMMENTS: Use wettable sulfur alone after full bloom as lime sulfur may burn foliage if applied during

warm weather. Lime sulfur is incompatible with most other pesticides. Check before use. Do not apply within 3 weeks of an oil application.

K. LIQUID LIME SULFUR# 2–3 gal/100 gal 48 0 MODE OF ACTION GROUP NAME (NUMBER1): Multi-site contact (M2) COMMENTS: Lime sulfur is incompatible with most other pesticides. Check before use. May burn foliage

if applied during warm weather. Do not apply within 3 weeks of an oil application. L. MICRONIZED SULFUR# (Thiolux, Microthiol, etc.) Label rates 24 0 MODE OF ACTION GROUP NAME (NUMBER1): Multi-site contact (M2) COMMENTS: Can be applied after bloom. Do not apply within 3 weeks of an oil application. M. MANCOZEB (Dithane) DF 3.2 lb/acre 24 77 MODE OF ACTION GROUP NAME (NUMBER1): Multi-site contact (M3) COMMENTS: Begin applications at 0.25- to 0.5- inch green tip and continue at 7- to 10-day intervals. Do

not exceed 22 lb/acre of Dithane. N. ZIRAM 76DF 1.5–2 lb/100 gal or 6–8 lb/acre 48 14 MODE OF ACTION GROUP NAME (NUMBER1): Multi-site contact (M3) COMMENTS: Apply from pre-bloom through cover sprays as needed. Do not apply more than 32

lb/acre/year. O. FIXED COPPER# Label rates 24 0 MODE OF ACTION GROUP NAME (NUMBER1): Multi-site contact (M1) COMMENTS: Apply at bud break using high label rate; later applications should be at low label rates.

May cause russetting at rates over 0.5 lb/acre. Not all copper compounds are approved for use in organic production; be sure to check individual products.

+ Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area


# Acceptable for use on organically grown produce. 1 Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of

actions (for more information, see http://www.frac.info/). Fungicides with a different group number are suitable to alternate in a resistance management program. In California, make no more than one application of fungicides with mode of action Group numbers 1,4,9,11, or 17 before rotating to a fungicide with a different mode of action Group number; for fungicides with other Group numbers, make no more than two consecutive applications before rotating to fungicide with a different mode of action Group number.


Armillaria Root Rot (Oak Root Fungus) (3/09) 60 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

ARMILLARIA ROOT ROT (Oak Root Fungus) (3/09) Pathogen: Armillaria mellea SYMPTOMS Roots infected with Armillaria mellea have white to yellowish fan-shaped mycelial mats between the bark and the wood. Dark brown to black rhizomorphs sometimes can be seen on the root surface. Apple rootstocks have some resistance to Armillaria, but if the level of inoculum is high in the soil and the strain of Armillaria is highly virulent, or the tree is already weakened by some other factor, the fungus can overcome this resistance. COMMENTS ON THE DISEASE The fungus survives on dead roots. MANAGEMENT There is no truly effective control for Armillaria root rot. Exposing an infected crown and upper root area of a tree infected with Armillaria mellea will stop the development of the fungus into the crown area and allow the tree to regrow. In spring, remove soil from around the base of the tree to a depth of 9 to 12 inches. Leave the trunk exposed for the remainder of the growing season. During the spring, summer, and fall, keep the upper roots and crown area as dry as possible.


Bacterial Blossom Blast (3/09) 61 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

BACTERIAL BLOSSOM BLAST (3/09) Pathogen: Pseudomonas syringae SYMPTOMS Fruit buds infected in early bloom stop growing, turn brown and papery, and may drop off. Later infections affect flower petals and stems, and fruit cluster bases turn brown or black. Infection usually does not move beyond the base of the fruit cluster; sometimes, however, fruit spurs are killed. Flower symptoms may closely resemble fire blight, but bacterial ooze is never present with blast as it is with fire blight. COMMENTS ON THE DISEASE Pseudomonas syringae is a widespread bacterium that infects many plant species and occasionally causes bacterial blossom blast on apples. Frost or freezing temperatures and free moisture are required for Pseudomonas infection to occur. Warm, dry weather halts its development. MANAGEMENT Bacterial blossom blast is difficult to control. When possible, use overhead sprinklers to prevent freezing. Monitor temperatures wherever freezing is most likely to occur in the orchard and turn on sprinklers when the temperature drops below 34°F (1.1°C). Turning on sprinklers before the initial drop in tempera-ture helps avoid the damage that results from evaporative cooling. Uniform coverage of all tree parts to produce a combination of water and ice is essential. Finally, keep sprinklers going until temperatures are well above 32°F (0°C) and the danger of frost is past. Organically Acceptable Methods The use of overhead sprinklers to prevent freezing and sprays of approved fixed copper products or streptomycin sulfate are organically acceptable methods. Treatment Decisions As an alternative to using overhead sprinklers, treat weekly with copper materials or antibiotics from green tip through bloom if blossom blast has been a problem and a freeze is likely. Apply chemicals before a freeze; treatment after symptoms appear is ineffective. Common name (trade name)


P.H.I.+ (days)

The following materials are listed in order of usefulness in an IPM program, taking into account efficacy. When choosing a pesticide, also consider information relating to environmental quality. Not all registered pesticides are listed. Always read label of product being used. A. STREPTOMYCIN SULFATE# (Agri-Mycin 17) 4.8 oz/100 gal 12 50 COMMENTS: Streptomycin-resistant strains of blossom blast bacteria are present in some areas. Do not

exceed 48 oz/acre/application. B. FIXED COPPER# Label rates 24 0 MODE OF ACTION GROUP NAME (NUMBER1): Multi-site contact (M1) COMMENTS: Application of copper-containing materials beginning at or about green tip may cause fruit

russetting on some cultivars, including Granny Smith. Copper-resistant strains of blossom blast bacteria are present in some areas. Not all copper compounds are approved for use in organic production; be sure to check individual products.

+ Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area





European Canker (3/09) 62 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

EUROPEAN CANKER (3/09) Pathogen: Nectria galligena SYMPTOMS In fall or spring European canker causes reddish brown lesions to appear on small branches just below leaf scars. These elongate into cankers with concentric ridges and may cause dieback of shoots in spring. Calyx rot of fruits can occur in years when rain precedes harvest. Pruning wound infections are seen occasionally (especially on the Delicious cultivar). On superficial examination, such infections may be confused with fire blight. COMMENTS ON THE DISEASE This fungus survives in old bark cankers and produces spores that enter fresh leaf scars during fall rains. The Delicious variety is most susceptible, followed by Gravenstein and Rome Beauty. This disease is worse in the Sebastopol area of Sonoma County in years with prolonged fall rains. MANAGEMENT European canker is managed primarily by pruning and protectant fungicides. Cankers should be pruned out of trees as they ultimately kill branches and also serve as sources of inoculum. Prune and burn diseased wood early in summer. At this time symptoms are obvious and spread of the fungus is not likely. Because infection occurs through leaf scars and leaves fall over a long period, two treatments are necessary each fall to protect new leaf scars. Organically Acceptable Methods Treatments with Bordeaux or approved fixed copper materials are organically acceptable. Treatment Decisions If European canker is damaging your orchard, apply a freshly prepared Bordeaux mixture of 10:10:100 or a fixed copper material at label rates during early leaf fall, before rains begin. Where the disease is serious, make a second application when three-fourths of the leaves have fallen. Common name (trade name)


P.H.I.+ (days)

The following materials are listed in order of usefulness in an IPM program, taking into account efficacy. When choosing a pesticide, also consider information relating to environmental quality. Not all registered pesticides are listed. Always read label of product being used. A. BORDEAUX MIXTURE# 10:10:100 Label rates see comments see comments MODE OF ACTION GROUP NAME (NUMBER1): Multi-site contact (M1) COMMENTS: When used on organically grown produce, all ingredients must be certified by the organic

grower's certifying agent. Observe the most restrictive label precautions and limitations among all the Bordeaux mixture ingredients, including the most restrictive PHI and REI. For more information on creating a Bordeaux mixture, see UC IPM Pest Note: Bordeaux Mixture, ANR Publication 7481 (available online).

B. FIXED COPPER# Label rates 24 0 MODE OF ACTION GROUP NAME (NUMBER1): Multi-site contact (M1) COMMENTS: Not all copper compounds are approved for use in organic production; be sure to check

individual products. # Acceptable for use on organically grown produce. 1 Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of



Fire Blight (3/09) 63 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

FIRE BLIGHT (3/09) Pathogen: Erwinia amylovora SYMPTOMS Fire blight causes blossom clusters to wilt and collapse in late spring. A brownish, sticky exudate is produced from diseased tissue. The tips of infected young succulent shoots curve into a characteristic shepherd's hook. COMMENTS ON THE DISEASE Erwinia amylovora overwinters in twig and branch cankers, is spread by rain splash and insects, and favored by warm, humid weather during bloom. Overhead sprinklers may aggravate the problem, especially in fire blight susceptible cultivars. Damage ranges from individual flower or shoot infections to death of limbs. Apple cultivars vary in susceptibility and extent of damage. For example, in Granny Smith, infections are usually limited and do not cause severe structural damage to the tree whereas Gala and Fuji trees may be devastated. The rootstocks M26 and M9 are very susceptible to this disease, and infections of these rootstocks can cause the trees to die. MANAGEMENT Fire blight development is influenced primarily by seasonal weather. Warm spring weather, accompa-nied by intermittent rain and hail, is ideal for disease development. Other influences on disease devel-opment are the varieties and rootstocks used in the orchard, location of the orchard, application of too much nitrogen fertilizer, heavy pruning, or over-irrigation. Management relies on maintaining trees in the proper range of vigor, applying blossom sprays of antibiotics or copper, and most importantly, promptly finding, removing, and destroying blight strikes. Remove holdover cankers by cutting back to healthy wood. This disease can be difficult to control. Organically Acceptable Methods Cutting out diseased wood and treatment with Bordeaux or approved fixed copper materials are organi-cally acceptable methods. Monitoring and Treatment Decisions Blossom applications of copper materials or the antibiotic streptomycin are necessary in some apple-growing areas to reduce the spread of fire blight bacteria. The timing of the first application is critical. In California, average daily temperatures or degree-hours are used to schedule fire blight sprays. Several mean temperature and degree-hour models are available to assist in predicting infection periods and the need for control. These models can be used to time antibiotic and copper treatments. The UC model recommends the first spray when bloom and mean temperatures reach 62°F in March, 60°F in April, and 58°F in May. This model recommends treating every 3 to 5 days until the end of rattail bloom regardless of changes in weather that would inhibit bacterial growth and infection. Newer degree-hour models are based on assessing actual conditions for bacterial growth and infection and also indicate when treatment is unnecessary. One such model is the degree-hour model, which takes into account early bloom and periods of continuous cool weather, allowing adjustments in treatment timings. Use of the degree-hour method requires a recording thermograph to obtain a continuous temperature reading in your orchard. One degree-hour equals 1 degree above 65°F for 1 hour. For example, a temperature of 70°F for 2 hours generates 10 degree-hours. Accumulate degree-hours each hour of the day unless 3 consecutive days below 66°F occur. In this case, the accumulation of degree-hours is then reduced to zero until temperatures again exceed 65°F. The accumulated degree-hour total is not reduced by continuous cool temperatures if the total has surpassed 400 degree-hours and has coin-cided with precipitation or simultaneous warm, humid infection periods of at least 57°F and 90% relative humidity. If the orchard is being irrigated, the humidity threshold is reduced to 80% relative humidity as measured outside the orchard. If possible, start the season with a full soil water profile so irrigation during bloom can be avoided. In the Sacramento Valley, treat within 24 hours preceding rain if 1 to 150 degree-hours have accumulated. In the North Coast region, treat within 24 hours preceding rain when more than 150 degree-hours have


Fire Blight (3/09) 64 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

accumulated. Treatment for both areas are recommended every 3 to 4 days when accumulation exceeds 150 degree-hours (Sacramento Valley) or 250 degree-hours (North Coast). Alternate day treatments are recommended in the Sacramento Valley whenever more than 500 degree-hours occur in conjunction with major bloom periods. Rain or hail may require immediate respray of the orchard if temperatures conducive to fire blight development exist. If conditions conducive to fire blight development have occurred and frost conditions develop that are severe enough to cause the pear skin to rupture, retreat immediately. Varying degrees of bacterial resistance to streptomycin exist in California. Common name (trade name)


P.H.I.+ (days)

The following materials are listed in order of usefulness in an IPM program, taking into account efficacy. When choosing a pesticide, also consider information relating to environmental quality. Not all registered pesticides are listed. Always read label of product being used. A. STREPTOMYCIN SULFATE# 4.8 oz/100 gal 12 50 (Agri-Mycin 17) COMMENTS: Streptomycin-resistant strains of fire blight bacteria are present in some areas. Provides both

contact and systemic control. Do not exceed 48 oz/acre/application. B. BORDEAUX MIXTURE# 0.5:0.5:100 Label rates see comments see comments MODE OF ACTION GROUP NAME (NUMBER1): Multi-site contact (M1) COMMENTS: In some years, application of copper-containing materials, beginning at or about green tip, may

cause fruit russetting on some cultivars, including Granny Smith. Provides contact control. When used on organically grown produce, all ingredients must be certified by the organic grower's certifying agent. Observe the most restrictive label precautions and limitations among all the Bordeaux mixture ingredients, including the most restrictive PHI and REI. For more information on creating a Bordeaux mixture, see UC IPM Pest Note: Bordeaux Mixture, ANR Publication 7481 (available online).

C. FIXED COPPER# Label rates 24 0 MODE OF ACTION GROUP NAME (NUMBER1): Multi-site contact (M1) COMMENTS: In some years application of copper-containing materials beginning at or about green tip may

cause fruit russetting on some cultivars, including Granny Smith. Provides contact control. Not all copper compounds are approved for use in organic production; be sure to check individual products.

+ Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be


# Acceptable for use on organically grown produce. 1 Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of actions

(for more information, see http://www.frac.info/). Fungicides with a different group number are suitable to alternate in a resistance management program. In California, make no more than one application of fungicides with mode of action Group numbers 1,4,9,11, or 17 before rotating to a fungicide with a different mode of action Group number; for fungicides with other Group numbers, make no more than two consecutive applications before rotating to fungicide with a different mode of action Group number.


Phytophthora Root and Crown Rot (3/09) 65 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

PHYTOPHTHORA ROOT AND CROWN ROT (3/09) Pathogen: Phytophthora spp. SYMPTOMS Symptom expression depends upon how much of the root or crown tissues are affected and how quickly they are destroyed. Generally, crown rots advance rapidly and trees collapse and die soon after the first warm weather of spring. Leaves of such trees wilt, dry, and remain attached to the tree. Chronic infec-tions, usually of the roots, cause reduction in growth and early senescence and leaf fall. These trees may be unthrifty for several years before succumbing to the disease. Phytophthora infections typically kill young trees because their root systems and crown areas are small compared to those of mature trees. MANAGEMENT Proper water management is the key to controlling root and crown rot. Do not allow water to accumulate or stand around crowns of trees. Provide adequate drainage or leave unplanted low spots in the orchard, areas that flood frequently, and places where water penetration is poor. Plant on berms. Once Phytophtho-ra is present in your orchard, the pathogen will remain; eradication is impossible. Avoid introducing infected plant material, infested irrigation water, or infested soil on farm equipment into uncontaminated soil. Periods of 24 hours or more of saturated soil favor Phytophthora infections. Conversely, good soil drainage and more frequent but shorter irrigations (e.g. pulse irrigation) reduce the risk of root and crown rot. Rootstocks vary in susceptibility to the different Phytophthora species; none are resistant to all pathogenic species of the fungus. Thus, the success of a rootstock may depend in part upon the species of Phytophthora present in the orchard. In general, MM 104 and MM 106 are more susceptible than are M 9 and M 26. Fungicides can help minimize losses. Common name (trade name)


P.H.I.+ (days)

The following materials are listed in order of usefulness in an IPM program, taking into account efficacy. When choosing a pesticide, also consider information relating to environmental quality. Not all registered pesticides are listed. Always read label of product being used. A. FOSETYL-AL (Aliette) 2.5–5.0 lb/acre 12 14 MODE OF ACTION GROUP NAME (NUMBER1): Phosphonate (33) COMMENTS: Foliar spray, 30–60 day interval. B. MEFENOXAM (Ridomil Gold EC) See label; rate varies with method 48 0 of application and size of tree MODE OF ACTION GROUP NAME (NUMBER1): Phenylamide (4) COMMENTS: Applications made in early spring and fall. + Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area


1 Group numbers are assigned by the Fungicide Resistance Action Committee (FRAC) according to different modes of actions (for more information, see http://www.frac.info/). Fungicides with a different group number are suitable to alternate in a resistance management program. In California, make no more than one application of fungicides with mode of action Group numbers 1,4,9,11, or 17 before rotating to a fungicide with a different mode of action Group number; for fungicides with other Group numbers, make no more than two consecutive applications before rotating to fungicide with a different mode of action Group number.


Powdery Mildew (3/09) 66 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

POWDERY MILDEW (3/09) Pathogen: Podosphaera leucotricha SYMPTOMS Powdery mildew is distinguished by superficial, white powdery growth on leaves and shoots that results in the stunting and distortion of young growth. Infected fruit are stunted and russetted, and fruit set may be reduced. COMMENTS ON THE DISEASE This is a major foliage disease of apples. The fungus overwinters in terminal buds that are white, flat-tened, and pointed. Disease development is favored by warm days and cool, moist nights. MANAGEMENT Powdery mildew is managed primarily by pruning infected shoots during dormancy or in early spring and by applying sprays as necessary in spring to prevent buildup of the fungus and damage to the crop. Remove infected shoot tips at pruning. Chemical control of powdery mildew is done in conjunction with controls for scab. Timing and choice of material may vary from orchard to orchard. Organically Acceptable Methods Pruning and treatments with lime and sulfur, sulfur alone, or certain horticultural oils can be used to treat organically certified produce. Treatment Decisions Preferred timing is an application at pink bud. If powdery mildew continues to be a problem in the orchard, apply additional treatments until terminal growth ceases. Common name (trade name)


P.H.I.+ (days)

The following materials are listed in order of usefulness in an IPM program, taking into account efficacy. When choosing a pesticide, also consider information relating to environmental quality. Not all registered pesticides are listed. Always read label of product being used. A. TRIFLOXYSTROBIN (Flint) 2–2.5 oz/acre 12 14 MODE OF ACTION GROUP NAME (NUMBER1): Quinone outside inhibitor (11) COMMENTS: Do not apply more than 2 consecutive applications before alternating. Do not apply more

than 11 oz/acre/season. B. FENARIMOL (Rubigan) 1EC 9–12 oz/acre 12 30 MODE OF ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3) COMMENTS: Do not apply more than 84 fl oz/acre/season. C. MYCLOBUTANIL (Rally) 40WP 1.25–2.5 oz/100 gal water/acre 24 14 MODE OF ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3) COMMENTS: Apply 400 gal/acre. Continue applications through the second cover spray at 7- to 10-day

intervals. Use high label rate if disease was present in previous years. For application by ground equip-ment only.

D. TRIFLUMIZOLE (Procure) 50WS 8–16 oz/acre 12 14 MODE OF ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3) E. MICRONIZED SULFUR# 10–20 lb/acre 24 0 MODE OF ACTION GROUP NAME (NUMBER1): Multi-site contact (M2) COMMENTS: May be used after bloom. Some russetting may occur in sensitive varieties if temperatures

exceed 80°F.


Powdery Mildew (3/09) 67 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html



P.H.I.+ (days)

F. LIQUID LIME SULFUR# 2 gal/100 gal dilute spray 48 0 . . . PLUS . . . WETTABLE SULFUR# 4–5 lb/100 gal 24 0 MODE OF ACTION GROUP NAME (NUMBER1): Multi-site contact (M2) COMMENTS: Do not use after bloom begins. Lime sulfur is incompatible with most other pesticides.

Check before use. G. TRIADIMEFON (Bayleton) 50DF 2–8 oz/acre 12 45 MODE OF ACTION GROUP NAME (NUMBER1): Demethylation inhibitor (3) COMMENTS: Do not apply more than 24 oz/acre/season. Do not graze livestock in treated orchards. H. THIOPHANATE METHYL (Topsin-M) 70WP 1–1.5 lb/acre 12 0 MODE OF ACTION GROUP NAME (NUMBER1): Methyl benzimidazole (1) COMMENTS: Resistance to thiophanate methyl may develop if this material is used repeatedly. It is

important to alternate this material with materials of a different chemistry. Do not apply more than 4 lb product/season.

I. LIQUID LIME SULFUR# 2–3 gal/100 gal dilute 48 0 MODE OF ACTION GROUP NAME (NUMBER1): Multi-site contact (M2) COMMENTS: Lime sulfur is incompatible with most other pesticides. Check before use. An in-season

application eradicates powdery mildew. J. HORTICULTURAL OIL# (Organic JMS Stylet Oil) 1–2 gal 4 0 MODE OF ACTION: Unknown COMMENTS: Use higher rate and/or shorter spray interval when disease conditions are severe. Check

with your certifier to determine other appropriate oils to use on an organically certified crop. + Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area





Nematodes (3/09) 68 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

Nematodes (3/09) Scientific Names: Root lesion: Pratylenchus vulnus and P. penetrans Root knot: Meloidogyne incognita, M. hapla, M. javanica, and M. arenaria Dagger: Xiphinema americanum DESCRIPTION OF THE PESTS Plant parasitic nematodes are microscopic roundworms that feed on plant roots. They live in soil and plant tissues. Of the many genera of plant parasitic nematodes detected in soils from apple orchards, two species of root lesion nematode, four species of root knot and the dagger nematode are believed to be the most economically important ones in California. Both species of root lesionnematode, Pratylenchus vulnus and P. penetrans are widely distributed throughout the state. Meloidogyne hapla is found throughout the state in association with crops such as alfalfa. Meloidogyne incognita, M. javanica, and M. arenaria occur throughout the warmer apple growing regions, with M. incognita having the most common occurrence. Dagger nematodes occur throughout the state, but are believed to be more widespread in the northern part. DAMAGE Root lesion nematodes penetrate into roots and cause damage by feeding and migrating through the cortical tissues. Interaction of root lesion nematodes with other soilborne organisms can increase injury to roots. They are occasionally associated with the apple replant disease, which is characterized by poor growth of young trees after transplanting. Feeding by root knot nematodes can impair root functions such as uptake of nutrients and water. Dagger nematodes feed from outside the roots, but can reach the vascular tissues with their long stylet. They are capable of suppressing growth of young trees, but the major problem caused by them is transmission of tomato ringspot virus, which causes apple union necrosis and decline, especially on the variety/rootstock combination Red Delicious and M106 rootstock. SYMPTOMS The symptoms described below are indicative of a nematode problem, but are not diagnostic as they could result from other causes as well. Damaged trees generally occur in a circular area within the orchard. Aboveground symptoms of nematode damage are lack of vigor, twig dieback, and decline in growth and yield. Infestation of older trees also results in chlorosis or yellowing of leaves, orange bark, fruit sunburn or sunscald typical in green varieties, and small fruit. Heavy infestation on young trees may result in stunting, and sometimes death. Nematode infestations may occur without inducing any above-ground symptoms. Below ground symptoms include poor growth of feeder roots or main roots and soil adhering to roots. Root knot nematode infestation will produce characteristic swelling of roots, called galls. FIELD EVALUATION To make management decisions, it is important to know the nematode species present and their popula-tion densities. If a previous orchard or crop had problems caused by the same species of nematode that are listed as pests of apple, population levels may be high enough to cause damage to young trees. If nematode species have not previously been identified, soil samples should be taken and sent to a diag-nostic laboratory for identification. Soil samples should be taken from within the root zone (6- to 36-inch depth). Take subsamples from the frequently wetted zones at the edge of the tree canopy, and include some feeder roots when possible. Divide the field into sampling blocks of not more than 5 acres each that represent cropping history, crop injury, or soil texture. Take several subsamples randomly from a block, mix them thoroughly and make a composite sample of about 1 quart (1 liter) for each block. Place the samples in separate plastic bags, seal them, and place a label on the outside with your name, address, location, and the current/previous crop and the crop you intend to grow. (See Integrated Pest Management for Apples and Pears, UC/ANR Publica-tion 3340, for more details.) Keep samples cool (do not freeze), and transport as soon as possible to a diagnostic laboratory. Request a species identification if either root lesion or dagger nematodes are found. Contact your farm advisor for more details about sampling, to help you find a laboratory for extracting and identifying nematodes, and for help in interpreting sample results.


Nematodes (3/09) 69 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

MANAGEMENT Cultural practices. Remove old roots and plant green manure cover crops resistant to root lesion nema-todes (such as the oat cultivar Saia) for 1 to 2 years or fallow the site for 4 years. If Pratylenchus vulnus is present, maintain a poor host for this nematode, such as tall fescue, red fescue, or perennial ryegrass as orchard ground cover. These crops are hosts for Pratylenchus penetrans and should not be used if this species of root lesion nematode is present. Use certified rootstocks or seedlings to establish new orchards. Improve soil tilth and drainage and control other pests. Proper irrigation and fertilizer application will also reduce stress on trees. Rootstock selection. Most standard rootstocks and some dwarfing rootstocks are believed to have some tolerance to P. penetrans, the root lesion nematode species that is frequently found in apple orchard soils in northern California. However, the dwarfing rootstocks are considered to be susceptible to P. vulnus, which is common in the orchard soils of the San Joaquin Valley. Always buy trees from California nurseries, which are certified nematode-free; do not purchase trees from out-of-state nurseries unless they are certified nematode-free. Treatment decisions. Trees planted in infested orchard sites that have been fumigated generally have improved growth and yields compared to those on nonfumigated sites. Common name (trade name)


P.H.I.+ (days)

When choosing a pesticide, consider information relating to environmental quality. Not all registered pesticides are listed. Always read label of product being used. PREPLANT A. METAM-SODIUM* 75 gal 48 0 (Vapam) COMMENTS: Metam-sodium can effectively control nematodes if applied properly, but it is not usually

applied properly, resulting in poor penetration of plant roots and difficulty in getting it to penetrate 4–5 feet down from the surface. Before applying this material, thoroughly cultivate the area to be treated to break up clods and deeply loosen the soil. After cultivation and about 1 week before treatment, preirrigate the field with 6–8 acre-inches of water in flood irrigation in basins. After treatment, do not plant for 30 days, or 60 days if soil is high in organic matter or cold (below 50°F). Fumigants such as metam sodium are a source of volatile organic compounds (VOCs) but are minimally reactive with other air contaminants that form ozone. Fumigate only as a last resort when other management strategies have not been successful or are not available.

B. 1,3-DICHLOROPROPENE* (Telone II) Label rates 7 days 0 COMMENTS: Fumigants such as metam sodium are a source of volatile organic compounds (VOCs) but are

minimally reactive with other air contaminants that form ozone. Fumigate only as a last resort when other management strategies have not been successful or are not available.

POSTPLANT A. FENAMIPHOS* 2.5 gal 48 72 (Nemacur 3) COMMENTS: Spray solution should be directed toward the base of the tree, where it will not come in contact

with any leaf surface. Irrigate immediately with sprinklers or microsprinklers. Read product use and chemiga-tion booklet.

+ Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be


* Permit required from county agricultural commissioner for purchase or use.


Apple Thinning Sprays (8/06) 70 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

Apple Thinning Sprays (8/06) Thinning is required to optimize fruit size and quality in apple orchards. Thinning also helps keep trees from biennial production and maintains a balance between vegetative growth and fruiting. Apples can be thinned chemically, by hand, or by a combination of both. HAND-THINNING The primary advantage of hand-thinning is that poor quality or damaged fruit can be removed. Hand-thinning is traditionally done after the "June" drop (late May) when the fruit are between the size of a cherry and a walnut, but this is too late to greatly affect biennial bearing. When hand-thinning, thin apples so that fruit clusters are about 4 to 6 inches apart with one fruit per cluster for fresh-market varieties, especially red ones, or two to three fruit per cluster for processing apples, green varieties, or light crops. Before hand-thinning, take into account the total number of fruit on the tree so that the crop is not over-thinned; this is especially important following chemical thinning. CHEMICAL THINNING Successful use of chemical thinners on apples is determined by many factors that influence the response of trees to applied chemicals. These include (but are not limited to): Weather before application. Cool, wet conditions may precondition leaves for greater absorption of thinning agents, leading to increased activity. Weather during/after application. Cool, wet, or humid weather prolongs drying, giving greater activity. High temperatures following application, particularly if they follow cool periods, can cause mild tree stress and tend to increase thinning activity of some chemicals. Tree condition. Stress from any source (low nitrogen, lack of water, root damage, heavy crop in previous year, shading within canopy, etc.) may increase thinning response to applied chemicals. Tree vigor. Young, excessively vigorous trees are easier to thin than older, moderately vigorous trees. Natural postbloom drop. Over-thinning may occur when natural postbloom fruit drop is heavy, particu-larly on Gala and Granny Smith. The rates and timings recommended here are those that have given the most acceptable and consistent results in field trials and grower experience to date; they are provided as suggested guidelines for growers who wish to begin accumulating experience in using chemical thinning as a management tool. Rates of chemical thinning agents should be adjusted within the recommended ranges based on bloom density and conditions during pollination and fruit set. When bloom is moderate or environmental conditions are favorable for thinning, use lower rates within the ranges specified. Use higher rates where bloom is heavy or environmental conditions are less favorable for thinning. Careful timing of spray application is important if predictable and acceptable results are to be expected. Proper timing, choice of chemical and rate varies dramatically according to variety. Most varieties are thinned at petal fall or shortly after fruit set. Because chemicals do not thin uniformly throughout the tree, supplement chemical thinning with hand-thinning to break up large clusters. Rates given pertain to applications using sufficient water to thoroughly wet trees (150–250 gallons/acre) without run-off. The optimum spray volume depends on tree size, planting density, row spacing, and stage of growth. Field experience with low-volume applications is lacking, and they are not recommend-ed. Reports from other areas indicate that low-volume applications yield less consistent results than dilute applications. To help prevent over-thinning in the lower portion of tree canopies, adjust the spray pattern to reduce the volume of solution applied to this area.


Apple Thinning Sprays (8/06) 71 Illustrated version at http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

SPECIAL PRECAUTIONS 1) In mixed variety blocks, take precautions to minimize drift of applied chemical thinners to non-target varieties. Spray drift from applications made to hard-to-thin varieties such as Fuji may over-thin Gala and Granny Smith. 2) When used at the rates suggested, carbaryl is toxic to honeybees if applied to bees during daytime while they are active in the orchard. Remove colonies from the orchard before spraying, and/or spray at night to prevent direct application to foraging bees. Remove flowering weeds or cover crop in the orchard before spraying. Granny Smith The best and most consistent results to date have been achieved using a single application of Sevin XLR Plus (carbaryl) at 1.5 to 4 pints (0.75–2 lb a.i.) per acre, applied when the largest fruit are 3/8 to 9/16 inch (10 –15 mm) in diameter. Gala The best thinning of the Gala variety has been achieved with a single petal fall application of Sevin XLR Plus at 3 to 4 pints (1.5–2 lb a.i) per acre plus the growth regulator Amid-Thin W (1-napthaleneacetamide) at 25 ppm. Follow-up hand-thinning is usually required following this treatment. Fuji Of the varieties discussed here, Fuji is the most difficult to thin with chemicals. The best and most consistent experimental results have been obtained with the following combination treatment: Sevin XLR Plus at 6 pints (3 lb a.i.) per acre plus the growth regulator Amid-Thin W at 50 ppm at petal fall, followed by another application of Sevin XLR Plus alone at 6 pints (3 lb a.i.) per acre when largest fruit are 3/8 to 9/16 inch (10–15 mm) in diameter. This combination has not provided complete thinning of Fuji, and follow-up hand-thinning is usually necessary. Pink Lady Experience with chemical thinning of this variety (in controlled experiments and commercial practice) is very limited, so the following treatment is suggested as a tentative guideline only. Pink Lady appears to be relatively easy to thin, increasing the risk of over-thinning under conditions favorable to thinning. The best and most consistent experimental results to date have been obtained with an early petal fall application of Sevin XLR Plus at 2 to 4 pints (1–2 lb a.i.) per acre. Golden Delicious There are several alternative treatments that alone or in combination are effective for thinning Golden Delicious. Tank mix combinations of Fruitone N (sodium salt of 1-naphthalenaecitic acid) at 5 to 10 ppm and Sevin XLR Plus at 4 to 6 pints (2-3 lb a.i.) per acre applied when the largest fruit are 3/8 inch (10mm) in diame-ter have provided more effective and consistent thinning of Golden Delicious than applications of either material alone.


Precautions for Using Pesticides (3/09) 72

This material is partially based upon work supported by the Extension Service, U.S. Department of Agriculture, under special project Section 3(d), Integrated Pest Management.

PRECAUTIONS FOR USING PESTICIDES Pesticides are poisonous and must be used with caution. READ THE LABEL BEFORE OPENING A PESTICIDE CONTAINER. Follow all label precautions and directions, including requirements for protective equipment. Apply pesticides only on the crops or in the situations listed on the label. Apply pesticides at the rates specified on the label or at lower rates if suggested in this publication. In California, all agricultural uses of pesticides must be reported. Contact your county agricultural commissioner for further details. Laws, regulations, and information concerning pesticides change frequently. This publication reflects legal restrictions current on the date next to each pest's name.

Legal Responsibility. The user is legally responsible for any damage due to misuse of pesticides. Responsibility extends to effects caused by drift, runoff, or residues.

Transportation. Do not ship or carry pesticides together with food or feed in a way that allows contamination of the edible items. Never transport pesticides in a closed passenger vehicle or in a closed cab.

Storage. Keep pesticides in original containers until used. Store them in a locked cabinet, building, or fenced area where they are not accessible to children, unauthorized persons, pets, or livestock. DO NOT store pesticides with foods, feed, fertilizers, or other materials that may become contaminated by the pesticides.

Container Disposal. Dispose of empty containers carefully. Never reuse them. Make sure empty containers are not accessible to children or animals. Never dispose of containers where they may contaminate water supplies or natural waterways. Consult your county agricultural commissioner for correct procedures for handling and disposal of large quantities of empty containers.

Protection of Nonpest Animals and Plants. Many pesticides are toxic to useful or desirable animals, including honey bees, natural enemies, fish, domestic animals, and birds. Crops and other plants may also be damaged by misapplied pesticides. Take precau-tions to protect nonpest species from direct exposure to pesticides and from contamination due to drift, runoff, or residues. Certain rodenticides may pose a special hazard to animals that eat poisoned rodents.

Posting Treated Fields. For some materials, restricted entry intervals are established to protect field workers. Keep workers out of the field for the required time after application and, when required by regulations, post the treated areas with signs indicating the safe re-entry date. Check with your county agricultural commissioner for latest restricted entry interval.

Preharvest Intervals. Some materials or rates cannot be used in certain crops within a specified time before harvest. Follow pesticide label instructions and allow the required time between application and harvest.

Permit Requirements. Many pesticides require a permit from the county agricultural commissioner before possession or use. When such materials are recommended, they are marked with an asterisk (*) in the treatment tables or chemical sections of this publica-tion.

Processed Crops. Some processors will not accept a crop treated with certain chemicals. If your crop is going to a processor, be sure to check with the processor before applying a pesticide.

Crop Injury. Certain chemicals may cause injury to crops (phytotoxicity) under certain conditions. Always consult the label for limitations. Before applying any pesticide, take into account the stage of plant development, the soil type and condition, the temperature, moisture, and wind. Injury may also result from the use of incompatible materials.

Personal Safety. Follow label directions carefully. Avoid splashing, spilling, leaks, spray drift, and contamination of clothing. NEVER eat, smoke, drink, or chew while using pesticides. Provide for emergency medical care IN ADVANCE as required by regulation.

ANR NONDISCRIMINATION AND AFFIRMATIVE ACTION POLICY STATEMENT FOR UNIVERSITY OF CALIFORNIA

PUBLICATIONS REGARDING PROGRAM PRACTICES The University of California prohibits discrimination or harassment of any person on the basis of race, color, national origin, religion, sex, gender identity, pregnancy (including childbirth, and medical conditions related to pregnancy or childbirth), physical or mental disability, medical condition (cancer-related or genetic characteristics), ancestry, marital status, age, sexual orientation, citizenship, or service in the uniformed services (as defined by the Uniformed Services Employment and Reemployment Rights Act of 1994: service in the uniformed services includes membership, application for membership, performance of service, application for service, or obligation for service in the uniformed services) in any of its programs or activities. University policy also prohibits reprisal or retaliation against any person in any of its programs or activities for making a complaint of discrimination or sexual harassment or for using or participating in the investigation or resolution process of any such complaint. University policy is intended to be consistent with the provisions of applicable State and Federal laws. Inquiries regarding the University's nondiscrimination policies may be directed to the Affirmative Action/Equal Opportunity Director, University of California, Agriculture and Natural Resources, 1111 Franklin Street, 6th Floor, Oakland, CA 94607, (510) 987-0096.

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