A Pocket GuideCommon Natural Enemiesof Crop and Garden Pests

in the Pacific Northwest

Determine the relative populations of pests andnatural enemies with preliminary monitoring. Thenuse the following tactics to enhance biologicalcontrol as part of an IPM program.

Protect natural enemies from disturbancessuch as pesticides, other managementpractices, their own natural enemies(e.g., ants), or adverse environmentalconditions.

Provide supplementary nectar or pollensources, alternate hosts, or shelter.

Manipulate the behaviors of natural enemieswith attractants or with plant structure andarrangement.

Augment natural enemy populations with massreleases of lab-reared individuals.

Introduce natural enemies that areabsent from the area.

Biological Control Lady Beetles(Coleoptera: Coccinellidae)

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Observation tipsAll stages found on plants.

Predacious activityAdults and larvae prey onaphids, scale insects, mites,and other small insects.

Similar beetles

Adalia bipunctata

IdentificationAdults orange to redwith black spots, ormostly black; larvaelonger; eggs inclusters.

larva

pupa

eggs

Coccinellanovemnotata

Hippodamiaconvergens

Olla abdominalis

Chrysomelid beetles

Using this Guide

The cards in this guide are designed to helpyou quickly learn the main groups of naturalenemies of crop and garden pests, theirpredacious activity, and tips for observing them.Photographs are of the most common species inthe Pacific Northwest.

Use this guide as a field supplement to otherpublications that provide more detail on how toscout for and manage specific pests and naturalenemies.

Print each sheet on regular paper or cardstock.Then fold on the central horizontal line and cuton the dotted orange lines to create three 2-sidedcards. (Laminate if needed.)

Most of the photographs in this pocket guide arefrom the Ken Gray collection.

All other photographs are from the author.

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When doing visual counts, also inspect theundersides of leaves.

Approach fast-moving insects slowly, oruse nets, beating trays, and traps to get acloser look.

General Observation Tips

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Green and Brown Lacewings

(Neuroptera: Chrysopidae and Hemerobiidae)

Green lacewings, e.g., Chrysopa californica

IdentificationLight green orbrown, largewings, longantennae; larvaeflat with longmouthparts;eggs on stalks.

eggslarva

ObservationtipsAdults often seenflying or on plants;eggs and larvae onplants. Brown lacewings, e.g., Hemerobius spp.

Predacious activityLarvae and adults mostly prey on aphids,mealybugs, and other small insects.

1⁄8 –1⁄3"

1⁄2 –3⁄4"

Distinguishing Natural Enemiesfrom Plant Pests in General

Observe the specimen to see whether itfeeds on animals or plants.

To see whether a particular natural enemyattacks a target pest species, placeindividuals of both species together in anenclosed environment that allows themroom to move.

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punchhole

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EC 1613-EDecember 2007

Archival copy. For current version, see: https://catalog.extension.oregonstate.edu/ec1613

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PredaciousHoverflies(Diptera: Syrphidae)

Observation tipsEggs, larvae, and tarlikeexcrement are found ataphid colonies; adultsmostly on or hovering atflowers.

Predacious activityLarvae prey mostly on aphids and scaleinsects; adults are flower feeders;some species not predacious.

IdentificationAdults mimic wasps andbees, but fly more quickly orhover, often have yellowmarkings; larvaemaggotlike; eggs small,whitish, and oblong.

1⁄2 –3⁄4"

Other insects confused with hoverflies

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larva egg

eggEupeodes fumipennis

puparium

Bee flies Bees Wasps

Scaeva pyrastri

aphids

Sphaerophoriasulphuripes

Parasitoid Tachinid Flies(Diptera: Tachinidae)

IdentificationAdults similar tohouseflies, but with verylong bristles on tail end;puparia red to brown andoblong; larvae inside host;eggs white and oblong onhost.

1⁄3 –2⁄3"

Flies commonly confused with tachinids

Flesh flies

Platyprepiaguttata

Observation tipsAdults seen on flowers; look foreggs on host, puparia near host

Eggs on host

Puparia next to hostsParasitic activityImportant endoparasitoids ofmany worm, beetle, sawfly, andbug pests; populations canincrease rapidly.

Blow fliesHouse flies

Ground or “Carabid” Beetles(Coleoptera: Carabidae)

Other beetles confused with carabids

Predacious activityPrey mostly on soil organisms,some feed on seeds.

IdentificationAdults are dark or metallicwith ridged wing covers;larvae grublike with largemandibles.

Observation tipsAdults mostly active at night;look for fast-running adultsunder objects on soil surfaceor in soil samples, larvae insoil samples.

Scaphinotusmarginatus

1⁄3 –2"

Pterostichus scitulus

Tenebrionidbeetles

Rove Beetles(Coleoptera:Staphylinidae)

Insects confusedwith rove beetles

Carrion beetles

Earwigs (adults > 1⁄3”)

IdentificationAdults small with short wingcovers not covering abdomen.

1⁄8 –1⁄3"

Philonthus sordidus

Leptacinus batychrus

Predacious activityPrey mostly on small soilorganisms.

Observation tipsAdults mostly active at night; look for fast-runningadults under objects on soil surface or in soil samples.

Damsel or“Nabid” Bugs(Hemiptera: Nabidae)

Other bugs confused with nabid bugs

Some of the thinnermirid bugs

Assassin bugs

Nabis spp. feeding on Lygus bugs

nymph

IdentificationAdults and nymphs longand thin with front legsslighty enlarged forgrabbing prey.

Observation tipsMost commonly foundrunning on low, densevegetation.

Predacious activityAdults and nymphs prey on otherinsects in same habitat.

1⁄3 –1⁄2"

Stilt bugs

PredaciousStink Bugs(Hemiptera:Pentatomidae) Perillus

bioculatus

Brochymena sp.

IdentificationAdults and nymphs have a broadpentagon or shield shape, usuallybrown or grey rather than green.

1⁄3 –2⁄3"

Predacious activityAdults and nymphs prey onother insects in same habitat.

Observation tipsFound on vegetation; may haveto observe activity to determinewhether the species ispredacious or herbivorous.

Similar-looking herbivorous stink bugs

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larva

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Archival copy. For current version, see: https://catalog.extension.oregonstate.edu/ec1613

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Minute PirateBug(Hemiptera:Anthocoridae)

Orius tristicolor

IdentificationAdults with a black and whitecross pattern; nymphs orangeto dark red.

< 1⁄8"

Predacious activityAdults and nymphs prey onother small insects in samehabitat.

Observation tipsFound on vegetation and flowers;more easily monitored with nets orbeating trays due to small size.

Other similar-looking small bugs

nymph

Chinch bugsBig-eyed bugnymphs

Some plantbug nymphs

Big-eyed Bugs(Hemiptera: Lygaeidae)

IdentificationAdults and nymphs with bigeyes; fast-moving and slightlylarger than minute pirate bugs.

< 3⁄16"

Predacious activityAdults and nymphs prey on othersmall insects in same habitat.

Observation tipsFound on vegetation orthe ground; more easilymonitored with nets orbeating trays due tospeedy flight and smallsize.

Other similar-looking small bugs

Chinch bugsMinute pirate bugs

Geocorispallens

nymph

nymph

Some plant bugnymphs

AssassinBugs(Hemiptera:Reduviidae)

IdentificationAdults and nymphsresemble damsel bugs,but larger, with a widerabdomen, thinner neck,and often with spines.

1⁄3 –1"

PredaciousactivityAdults and nymphs preyon many types of insectsin same habitat.

Observation tipsFound on vegetation and flowers.

Damsel bugs

Other bugs confused with assassin bugs

Ambush bugs Stilt bugs

nymph

nymph

Ambush Bugs(Hemiptera: Phymatidae)

IdentificationAdults and nymphs are oftencamouflaged like leaves andflowers to ambush prey.

Predacious activityAdults and nymphs prey on otherinsects in same habitat.

Observation tipsFound on flowers andvegetation.

Similar-looking bugs

1⁄3 –2⁄3"

Phymatametcalfi

nymph

Leaf-footed bugsAssassin bugs Alydid bugs

(Coleoptera:Cicindellidae)

Observation tipsAdults usually seen flyingover and running on lightand sandy soils.

Predacious activityAdults and larvae prey onmany types of insects in thesame habitat.

Cicindela longilabris columbiana

IdentificationAdults shiny with large eyesand mandibles; very fastrunners and flyers.

1⁄3 –2⁄3"

Cicindela oregona

Similar beetles

Soft-winged flower beetles Ground beetles

Soldier Beetles(Coleoptera:Cantharidae)

IdentificationAdults are long and thin withlong antennae, often with redor orange markings.

PredaciousactivityAdults prey on otherinsects in same habitat.

Observation tipsFound on leaves andflowers.

Similar types of beetles

1⁄2 –1"

“Fireflies”

Cantharis sp.

Podabrus sp.

Podabrus cavicollis

Soft-winged flower beetles

Tiger Beetles

nymph

Podabrus pruinosus

Archival copy. For current version, see: https://catalog.extension.oregonstate.edu/ec1613

Larger Parasitoid Wasps(Hymenoptera: e.g., Ichneumonidae,Braconidae)

© 2007 Oregon State University. This publication may be photocopied or reprintedin its entirety for noncommercial purposes. This publication was produced anddistributed in furtherance of the Acts of Congress of May 8 and June 30, 1914.Extension work is a cooperative program of Oregon State University, the U.S.Department of Agriculture, and Oregon counties. Oregon State University ExtensionService offers educational programs, activities, and materials without discriminationbased on age, color, disability, gender identity or expression, marital status, nationalorigin, race, religion, sex, sexual orientation, or veteran’s status. Oregon StateUniversity Extension Service is an Equal Opportunity Employer.Published December 2007.

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Support for this project provided by:

Any comments or questions regarding thecontent of this pocket guide are welcomed andcan be directed to:

Mario AmbrosinoIntegrated Plant Protection Center2040 Cordley HallCorvallis, OR 97331(541) 737-2638ambrosim@science.oregonstate.edu

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Vespid Wasps (Yellowjackets,Hornets) (Hymenoptera: Vespidae)

Thread-waisted Wasps(Hymenoptera: Sphecidae)

Parasitized and DiseasedInsect Pests

Smaller Parasitoid Wasps(Hymenoptera: e.g., Chalcididae,Eulophidae, Encyrtidae, Trichogrammatidae,Aphelinidae, Pteromalidae)

IdentificationBraconids are < ½",Ichneumonids areusually larger with alonger abdomen.

Parasitic activityKill hosts by parasitism orby piercing and feeding;hosts include insect larvae,pupae, and aphids.

Observation tipsAdults found at flowersor looking for hosts;monitor by looking forparasitized hosts (p. 23).

Predacious activityMany species specialize onvarious insect prey species.Females capture prey andbring back to larvae in nests.

1⁄4 –2"

IdentificationStout-bodied to slender, oftenwith a very narrow waist andwide head.

Observation tipsActive near open sandyareas and flowers.

Trypoxylon sp.

Other insectsconfusedwith thread-waistedwasps Hoverflies Vespid wasps

Sceliphron caementarium

Predacious activityAdults bring masticated insects,meat, and nectar of many typesback to larvae in large nests.

IdentificationMedium to large, black withyellow or white markings;wings smoky and foldedlongitudinally.

Dolichovespula maculata

Bald-facedHornet

1⁄2 –11⁄2"

Western yellowjacket

Vespula pensylvanica

Other insects confused with vespid wasps

Thread-waisted waspsHoverfly

Ichneumonidwasps

Braconidwasps

Ischnus inquisitorius

Macrocentrus iridescens

Apantelesaristoteliae

IdentificationMostly <1/ 8"

Observation tipsMonitor by looking forparasitized hosts (p. 23).

Parasitic activityKill hosts by parasitism;hosts include insecteggs, larvae, and pupae.

Chalcid wasp

Aphelinus perpallidus

Encrytid wasp

Chrysocharis sp.

Eulophid wasp

Microgaster sp.

Pteromalid wasp

Identification andobservation tipsParasitoid larvae and pupae aredifficult to identify. One of thebest identification methods is tocollect hosts that look unusualand hold in a container until theparasitoid develops into anadult.

Individuals with a viral or bacterialinfection often are darkened orwatery. Individuals with a fungalinfection often look fuzzy.

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Aphid “mummies”

parasitoidlarvae on hosts

pupae

Archival copy. For current version, see: https://catalog.extension.oregonstate.edu/ec1613