1
Common Insect Pests of
Central Virginia
Dan Nortman
Extension Agent, Agriculture and Natural Resources, Horticulture
York/ Poquoson
Two-spotted spider mite
Oak mite damage Aphids
• Piercing mouthparts
• Honeydew
• Reduce vigor
• Many different
species and hosts
• Tended by ants
Aphids
note “tail pipes” life stages
distortion of birch leaf
Aphids
• Monitor for distorted
foliage
• Monitor for
honeydew, sooty
mold
• Monitor for natural
enemies
2
Scale insects Sedentary, Piercing mouthparts, hatchlings are the
only mobile stage (“crawlers”)
• Armored scales
–Small (1/8th
inch)
–Shield
–Crawlers
–Dormant oil
• Soft Scales
–Larger (1/4 inch)
–Hemispherical
–Crawlers
–Dormant oil
Scale Life Stages
Soft scale: Cottony maple scale Cottony maple scale
Soft scale: Wax scale
adult scales infested boxwood
Homoptera, Soft scale:
Oak lecanium scale
scale with crawlers
infested branch
parasitic wasp
3
Homoptera: Armored scales
gloomy scale obscure scale
tea scale
parasitic
wasp
Euonymus
scale
•1/10”
•Oyster-shaped chestnut brown
•Fruit and shade trees
•Ornamental shrubs
•Over 130 host plants
•2 generations
•Treat May 1-20 and July 15-25
Oystershell Scale Lepidosaphes ulmi
•1/16”
•Circular, smoky black with gray ring
•Fruit and shade trees
•Ornamental shrubs
•Over 60 host plants
•3 generations
•Live born
San Jose Quadraspidiotus perniciosus
Spittlebug Brown Marmorated Stinkbug
• Invasive exotic
• Causing major damage on
several types of plants
– Especially vegetables
– Heavy crape myrtle feeders
– Tree Fruit
• House invader
• Lots of stuff to kill
– Plant specific
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Harlequin bug
http://insects.tamu.edu/images/insects/color/harleq2.jpg
Hemiptera:
Harlequin bug • Harlequin bugs are
common on kale,
mustard, and other
crucifers (cole crops)
including weeds.
• Type of stink bug
• yellow spots
Harlequin bug Hemiptera:
Squash bug • Squash bug is common in
spring and late summer
• all cucurbits
• Causes wilted leaves, low
fruit production
http://www.uidaho.edu/so-
id/entomology/Home_&_Garden/squash%20
bug.jpg
Squash bug, Hemiptera
Hemiptera: Azalea lace bug
life stages
5
Azalea Lace Bug
• Monitor
– Overwintering
population
– Adult emergence
• Selective spraying
(sunny areas)
• Follow-up
monitoring
Scarabaeidae
• Scarab beetles
• Lamellate antennae
• Leaf feeders, some decomposers
• Common landscape and garden pests: – Japanese beetle
– Rose chafer
– Lawn grubs
– June beetles
Japanese beetle
• Very wide host range
• Foliar devastation-
Rosaceae
• Lawn trouble
• Lawn insecticides-
targeting grubs
• Milky spore- works
selectively
• Exclusion- Hand
pollination may be
required
• Shake into a soapy
bucket
Japanese Beetle
Japanese Beetle
Other Beetles
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Locust Borer
• Common borer in
black locust
• Generally won’t kill
the tree
Twig Girdler
• Chews a ring on a twig to feed and lay an egg
• Twig dies, larvae develops in dead part
• Twig falls off of tree
• Many hosts – Pecan, hickory, oak
• Collect and burn fallen twigs
Curculionidae
• Two groups
– Weevils
– Bark beetles
• Weevils have snout,
bark beetles don’t
• Weevils feed on plant
material
• Bark beetles are
pests in wood
Weevils
• Wide variety of hosts
• Some common pests – Boll weevil
– Plum curculio
• Common in stored grains
• Botanical insecticides
• Not usually a problem for the home gardener
Bark Beetles
• Small, brownish
beetles
• Some eat wood
• Others eat fungus
that they “farm”
• Systemic
insecticides are
best
Damage comparison
Bark Beetle Buprestid
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Mexican Bean Beetle
• Can be devastating in
large numbers
• Attacks most legumes
• Planting early can
help
Meloidae • Blister beetles
• Spanish Fly
• Leathery elytra
• “Fleshy” bodies
• Occasional pests
Chrysomelidae
• Leaf beetles
• Most common garden
pest
– Colorado potato beetle
– Spotted and striped
cucumber beetle
– Asparagus beetle
Colorado Potato Beetle • Orange and black stripes
on elytra
• Very, very destructive
• Prone to resistance
• The bane and funding
source of many, many
entomologists
Most common Defoliators are
caterpillars: Lepidoptera
• Control when small
• Healthy trees will refoliate again or next season
Yellownecked caterpillar
Image from Barb Leach
Eastern tent caterpillar
larva
eggs
tent
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Eastern tent caterpillar: pest of wild
cherry and some fruit trees • Trees will put out leaves again
• Prune egg masses Nov.-Mar.
• Remove small tents manually
• Apply insecticides to tents
• Migrating last instar larvae cannot be controlled
• Recreational caterpillar burning: DO NOT torch tents
Gypsy moth
mature larva
laying eggs
defoliated forest
Gypsy moth -
treatments
pheromone traps
trapping with burlap bands
Gypsy Moth
• Remove accessible egg cases
• Apply burlap bands to selected trees • Check mid May or June
• Fourth instar or later
• Pupae
• Egg masses
Indicates need to treat next year
• Apply duct tape coated with adhesive
• Avoid Preferred hosts
• Treat – Bt
– Dimilin
Eastern Tent Caterpillar vs. Gypsy
Moth
larva Gypsy Moth Eastern Tent Caterpillar
Fall Webworm
• Highly
Polyphagous
• Loves Pecan
• Damage
unsightly, but
usually negligible
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Lepidoptera: Bagworms Bagworm
Lepidoptera: Orangestriped
oakworm
adults larvae
http://www.hort.uconn.edu/ipm/veg/pics/icw2.jpg
Imported cabbageworm:
Lepidoptera
Tomato
Hornworm
• Tomato hornworms are
late summer defoliators
• hand-pick, keep
parasitized worms
• Tobacco hornworm,
Manduca sexta
• Tomato hornworm,
Manduca
quinquemaculata
Tomato hornworm
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Sesiidae
• Clearwing moths
• Soft bodied vs. beetles
• A native pest that can be a serious tree fruit pest
• Take advantage of graft sites
– Facilitates egg laying • Beetle counterparts, adults
help
Dogwood Borer • Look for sloughing bark
near graft or damaged
sites
• Larve develop in
cambium
– Overwinter under bark
– Will often chew to the
outside for emergence
Peach Tree Borers
•Synanthedon exitiosa
• Peachtree Borer
•Synanthedon pictipes
• Lesser peachtree borer
•Cherries, peaches, plums,
apricots
Peach Tree Borers
• Maintain tree health
• Peachtree borer Isomate mating disruption – Pheromone based
– Females release a plume
– Males track the plume
– MD causes males to follow false plumes, decreasing mating
Sawflies
• Hymenoptera pest
• Pests of evergreens
and other plants
• Caterpillar like larvae
• 6+ pairs of prolegs
– Caterpillars have 2-4
Good Bugs
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Ladybird beetles
• Larvae are voracious
• Adults also feed
• Probably saved
organic soybeans in
MI
Lacewings
• “Little gator” larvae
• Adults feed on nectar
Syrphid Fly
• Larvae are excellent
predators
• Adults are nectar
feeders
Cecidomyiid larvae
• Small larvae, excellent predators
Parasitic Wasps Tachinids
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Minute Pirate Bug
• Great predators on
thrips and spider
mites
• Can bite
Dan Nortman
Virginia Cooperative Extension
Extension, Agriculture and Natural
Resources, Horticulture
100 County Drive, Yorktown, VA
757-898-4940
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