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September Scouting Tips

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Insects to be on the Lookout for in August

Field and Vegetable Crops

Insect:Host(s)DescriptionTreatment timing*
Diamondback Moth: Most crucifers, but in particular cabbageAdults are small moths  that have a diamond pattern on their backs when they hold their wings at rest. The small pale larvae at first skeletonize the leaves and later may eat holes. The pupae form a net of silk over themselves when they pupate on the leaves.This was a big problem in 1988. So far the IIL has not received reports of damage but growers should be on the lookout. Ambush, Pounce or Monitor are recommended. Orthene (labeled crops), Pydrin and Phosdrin will also  give good control.
Mexican Bean Beetle: Bean cropsAdults are hemispherical in shape and yellowish brown in color. They have black spots on the wing covers. The larvae are less than 1/2" long and have many spines.Insecticide applications are recommended if more than 30% defoliation takes place.
Stink Bug: Many crops but in particular pepper and  tomatoBarrel shaped eggs are laid on the undersides of leaves, nymphs are black and white or red or green. Adults are green or tan. All stages have piercing sucking mouth parts. Damage to pepper and tomato appears as white haloes and deformations on the fruits.Removing weedy growth that harbors stink bugs will cut down on native breeding sites. Spot treatments of insecticides when stink bugs are seen is recommended.

Fruit Insects

Insect:Host(s)DescriptionTreatment timing*
Variegated leaf roller and Tufted Apple Budworm: Both are general feeders but are pests on apple and peachEggs are laid in masses in which the eggs overlap much like fish scales.  The egg masses are found on the leaves.Treat when egg masses are about to hatch (dark head stage).
White Apple Leafhopper:  AppleLook for small, pale, leafhoppers on the under sides of the leaves. This will be the second generation.Check several trees and treat if a high density is found on all trees. This pest may be bad in regions with dry weather.

Ornamental Insects

Insect:Host(s)DescriptionTreatment timing*
Bagworm: Conifers, maples sycamores, box elder, and many othersCaterpillars form "bags" around their bodies made of silk and plant debris.  They overwinter as eggs in the bags; the eggs hatch in late May and early June.Pick off and destroy all bagworms now and/or treat with an insecticide in mid June. Next spring, early, pick off all bags you can find.
Spruce Mite: Arborvitae, spruce, juniper, hemlockSmall mites, 1/50" long, cause a yellow stippling on the needles and die back of lower branches.Spray with a miticide early fall.
White Peach Scale: Most fruit trees and many ornamentalsThe female scale is white with a yellow mark on the center and has a rounded shape. The male is solid white and elongated in  shape. Crawler stage is April 25-May 15, and July 1-15, and August 20-September 15.Treat July 5-15, and September 1-10. Next year treat also May 1 and May 10.

Lawn and Turf

Insect:Host(s)DescriptionTreatment timing*
Scoliid Wasps: Any grassy areasBlack hairy wasps about 1 inch long with a red tip on the abdomen and two distinctive yellow spots on the middle part of the abdomen. Often seen flying low over the ground.No need for control, these wasps are parasites of white grubs.

* 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.