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

4

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

6

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

10

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

11

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

12

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

dnortman@vt.edu