Author: Eric R. Day, Insect Identification Laboratory, Department
of Entomology, Virginia Tech
Insect:Host(s) Description Treatment timing*
FIELD AND VEGETABLE CROPS
Aphids: Look for small soft- Cut out and destroy small
Any crop but in bodied insects causing localized areas on plants or
particular cru- the leaves to be stunted, treat with an insecticide
cifer crops yellowed, and/or curled. labeled for aphids and that
particular crop.
Black Cutworm Medium to large cater- If more than 5% of the plants
and other pillars cut off plants at are cut then control with an
Cutworms: the base. Inspect newly insecticide or bait is
Many crops but planted seed beds and newly warranted.
in particular set plants.
corn
Colorado Potato Adults are yellow with For small gardens, beetles
Beetle: brown stripes, they are can be removed by hand-
Potato, tomato, oval-convex in shape. The picking, larger areas or
eggplant,pepper, larva is yellowish red or heavy infestations will
tobacco, and orange and has a row of require the use of insect-
other solan- black spots along each side icides.
aceous plants of its body.
Cucumber Beetle: Two beetles feed on cucur- Foliar sprays may
Cucumber, can- bits in Virginia, the spot- be necessary in some
taloupes, gourd, ted cuc. beetle is pale cases. To prevent bac-
squash, and green with black spots on terial wilt treat when 1
watermelon are its wing covers, the striped beetle per 100 row feet
preferred hosts. cuc. beetle is pale green is found.
They are found with black stripes on its
on other crops wing covers. Both transmit
but are not as bacterial wilt of cucurbits.
important.
European Corn On corn look for shot-hole Treatment on field corn is
Borer: Many damage in the whorl late- warranted if more than 50%
crops but in June and early-July. In of the plants have an egg
particular corn addition, look for the flat- mass. Count 50 random plants
tened egg masses with eggs and if the average
overlapping like fish scales on number of egg mass
on the undersides of the exceeds 0.5 then treatment
leaves, look from the first may be necessary. Treatment
of July to mid July for the must be made just after egg
egg masses. Be sure to scout hatch. Growers in Virginia
the inner parts of the field usually treat between the
because the border rows first and fifteenth of July
tend to have higher pop- when necessary.
ulations of ECB.
Insect:Host(s) Description Treatment timing*
Flea beetle: Small black beetles jump- Spray with Sevin when damage
Corn, eggplant, ing like fleas when dis- becomes severe.
and many other turbed from the leaves of
crops a plant. They scrape the
upper epidermis layer off
the leaf and sometimes
fruit leaving a brown scar.
Imported Velvet green caterpillars Treat when caterpillar
Cabbageworm: with a faint yellow stripe populations reach a
Cabbage, broc- down the back and a row of threshold of one worm
coli, cauli- yellow spots on each side. per plant, repeat every
flower, and Medium sized. 5 to 7 days as needed.
other crucifers
True Armyworm: Medium to large cater- When defoliation reaches
Corn and other pillars, brown with 20%, insecticide control
grass plants, yellow markings, usually is warranted.
but on many veg- feeding on the upper parts
etable crops as of the plant at night.
well
Stink Bug: Barrel shaped eggs are Removing weedy growth that
Many crops but laid on the undersides of harbors stink bugs will cut
in particular leaves, nymphs are black down on native breeding
pepper and and white or red or green. sites. Spot treatments of
tomato Adults are green or tan. insecticides when stink
All stages have piercing- bugs are seen is recom-
sucking mouth parts. mended.
Damage to pepper and
tomato appears as white
halos and deformations
on the fruits.
Squash Bug: Nymphs are grayish white Handpicking works well
All cucurbits; with dark heads and appen- in small gardens. Chem-
squash bugs pre- dages. Adults are oval ical control might be
fer squash, elongate, light gray, and needed in larger
pumpkin, cucum- mottled yellow on the operations.
ber, and melon underside. Nymphs tend
in that order to be found on the basal
portions of the vine.
FRUIT INSECTS
Codling Moth: Pinkish-white caterpillars If using pheromone traps,
Apple and pear enter fruit at calyx end treat if you exceed 5/trap/
primarily, but and tunnel all the way week.
cherries,peaches, to the core. Adult moths
plums, apricots, are grayish-brown with
and similar irregular golden brown
fruits are lines on the fore wings.
attacked. 1/2-3/4" wingspan.
Insect:Host(s) Description Treatment timing*
European Red Mites are very small and This mite is resistant to
Mite: Apple range from red to green. many miticides, so make sure
pear, plum, Foliage turns a sickly that the chemical you will
prune, and bronze color as if covered use is effective. A dormant
many other with dust. oil applied at the 1/2"
trees and shrubs green leaf stage or earlier
in the spring is important
also.
Green Apple Pale green nymphs on the Treat when 50% or more of
Aphid: underside of leaves and the shoots are infested.
Apple, pear new shoots, often a
problem on trees with
excessive shoot growth
due to overfertilization.
Peach Tree Look for a mass of gum Adults emerge July-
Borer: Peach, and frass at the base of September; treat during
plum, cherry, the trunk, white larvae the first week of July.
nectarine, will be found under the
apricot bark from 3" below the
soil level to 10" above.
San Jose Scale: Scales are dirty gray Treat June 10-15,
Apple, pear, with a dark concentric late-July.
cherry, and many ring on the center.
other fruit trees Scales infest the bran-
ches, twigs, and fruit.
Variegated Leaf- Eggs are laid on leaves Treat when egg masses are
roller and in masses in which the about to hatch (dark head
Tufted Apple eggs overlap much like stage).
Budworm: fish scales.
Both are general
feeders but are
pests on apple
and peach
ORNAMENTAL INSECTS
Azalea Bark Look for white cottony Treat June 10 and 20.
Scale: Azalea, sacs covering dark red
blueberry, females and eggs on the
rhododendron forks of branches and twigs.
Azalea Stem Look for tips dying back Treat mid-May and mid-
Borer: Azalea, and yellow legless grubs June with an insect-
rhododendron, up to 1/2" long boring icide or cut out and
mountain-laurel, in twigs and trunk. destroy dead and dying
blueberry tips as noticed. Borer
paste in the holes
will give some control
also.
Insect:Host(s) Description Treatment timing*
Bagworm: Caterpillars form "bags" Pick off and destroy all
Conifers, maples around their bodies made of bagworms now and/or treat
sycamores, box- silk and plant debris. with an insecticide in mid-
elder, and many They overwinter as eggs June. Next spring, early,
others in the bags; the eggs pick off all bags you can
hatch in late May and find.
early June.
Black Vine Adults notch leaves inward Treat with an insecticide
Weevil: Nearly from the outer margin. in the second or third week
80 hosts inclu- Larvae feed on the roots of June. Spray the leaves
ding most broad- and weaken the plant, branches, trunk, and soil
leaved evergreens often causing it to wilt. under the plant.
Bronze Birch Look for the top of the Treat mid-May, and
Borer: Birch, tree dying back and up to early-, mid-, and
cottonwood, 1" long flat-headed borers late-June; spray trunk
poplar, aspen under the bark. and branches heavily
and leaves lightly.
Boxwood Leaf- Look for yellowed Treat early June; the
miner: Boxwood leaves and leaves with addition of a wetting agent
small brown spots. This may be helpful.
time of year the adult
yellow flies may still
be found on the foliage.
Cottony Maple Look for cottony masses Treat June 10 and 20.
Scale: on the undersides of twigs
All maples, and branches. Foliage on
locust, white affected branches may turn
ash, red mul- yellow and the branch may
berry, linden die.
boxwood and
many others
Cottony Camellia Look for a long fluted Treat June 10-20.
Scale: yew (taxus), cottony egg mass on the
camellia, holly undersides of leaves and
branches.
Eastern Pine Look for yellow loopers Treat if damaging numbers
Looper: pitch with black markings are found.
red, shortleaf, feeding on the foliage.
and loblolly Usually a minor pest, but
pine because large numbers of
the adult moths were seen
this spring it may present
a problem on some plantings.
Elm Leaf Newly hatched larvae are Control newly hatched
Beetles: Elm yellowish with black larvae in late-May
markings; adults are olive and early-June.
green with two black lines.
Insect:Host(s) Description Treatment timing*
European Fruit Large hemispherical to Treat June 10-15.
Lecanium Scale: oval scale, shiny brown or
Most fruit trees reddish-brown but some-
and many orna- time covered with a white
mental plants. powder. On the bark and
twigs in the winter and
on the leaves near the mid-
rib during the summer.
Fall Webworm: Eggs are laid in a mass Nests can be pruned out in
Most fruit and of 200 to 500 often cover- early summer or if a large
nut trees as ed with a woolly layer of number of nests exists,
well as some scales. Large groups of treat mid- to late-June
hardwoods and larvae form a nest at the or when new larvae appear.
shrubs. tip of a branch.
Florinia Hemlock Cast skins give trees a Treat May 20-25 and
Scale: Hemlock white-washed appearance June 5-10
fir, spruce, yew with many scales on the
undersides of needles.
Scales under close exam-
ination are yellow in
color. Crawler stage
peaks May 15-June 20.
Gloomy Scale: Dark gray and circular Treat June 20-30.
Mostly soft scales, blending in Note this scale is
maples closely with the color often controlled by
of the bark. its natural enemies.
Hickory Leaf Galls shaped like No control is needed on
Stem Gall: bullets develop on the large trees as these galls
Hickory petioles and shoots. do not harm them. On small
Leaves with galls fall trees or nursery stock
off the tree prematurely control may be warranted
causing concern by the
tree's owner. Galls are
formed by aphids.
Holly Leafminer: Look for long serpentine Treat mid-June with a
Native and or blotch mines in the systemic insecticide.
English holly leaves. Heavily infested Small numbers of infested
leaves turn yellow-brown. leaves can be picked off
Inside the leaves will and destroyed.
be small pale larvae.
Juniper Scale: Crawler stage is from Treat April 10-15
Juniper April 5-22 and June and/or June 10-15.
5-20. Scales have an
elongate white covering
with a yellow cap at one end.
Japanese Scale: Long and narrow scale, Treat at 2-week intervals
Maple, privet dull white in color, from June 1-Sept. 1.
often found on the
trunks and branches.
Insect:Host(s) Description Treatment timing*
Japanese Weevil: Cuts broad notches on the Treat the second and
Many ornamental outer margins of leaves. third weeks of June.
plantings as
well as garden
plants
Lace Bugs: New damage will not be Lace bugs overwinter as
andromeda, oak apparent yet this year, adults on deciduous plants.
azalea, walnut but last season's damage Treat in late May and repeat
rhododendron, appears as stippling in June and July. On ever-
sycamore and brown droppings on greens lace bugs overwinter
the leaves. in the egg stage.
Lecanium Scale: Scales are dark to light Treat June 15-20.
Oak brown and elliptical in shape,
often tapering at both ends.
Mimosa Webworm: Larvae feed gregariously Treat when trees show
Mimosa and in a web spun over the first signs of feeding in
honeylocust flowers and leaves and June. May need to repeat in
later feed individually mid-July and mid-August.
on leaves and pods.
Pine Bark Aphid: Look for cottony masses Treat late-June and
Principally on on the bark and branches mid-August. Make sure the
white pine but covering small, aphid-like, insecticide is applied with
on other pines pale-green insects. strong stream that
as well penetrates the "cotton".
Small populations can be
dislodged with a strong
stream of water alone.
Rhododendron Larvae bore in the sap- Treat June 10-15, and
Borer: Rhodo- wood just under the bark, July 5-10. Prune out any
dendron, some- causing the branches to infested branches.
times azalea and wilt and die. Adults are
mountain-laurel clear-winged moths.
San Jose Scale: Scales are dirty gray Treat June 10-15, July
Many trees and with a dark concentric 10-15, and September 10-15.
and shrubs ring on the center.
Scales infest the bran-
ches, twigs, and fruit.
Wax Scale: A globular off-white Treat June 10-30.
Holly, euonymus, scale found on the twigs
pyracantha, box- and leaves. So named
wood, hemlock, because of its waxy cover.
and others
White Pine The larvae is a yellowish, Prune and destroy
Weevil: Pines legless, grub that feeds infested shoots in
and spruces under the bark on the May and June.
terminal leader. The leader wilts and droops
in the spring, indicating
the presence of the grub.
* See Virginia Pest Management Guides for recommendations on insecticides and rates. Use insecticide applications only when high population levels demand control action. Most plants can support small populations of pest insects.