ANR-191, Reprinted May 1998. Patricia P. Cobb, Extension Entomologist, Professor, Entomology, Auburn University

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Controlling Bagworms on Ornamentals

Bagworms are serious pests of ornamental evergreens in Alabama. Their spindle-shaped bags made of silk and portions of foliage and twigs may go unnoticed until serious damage occurs to the plant.

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Description, Life History, And Distribution

The bagworm adult female really doesn't resemble a moth at all. She has no eyes, is wingless, and never leaves the bag she made as a caterpillar. The adult male is typically mothlike. He is black, with clear wings that have a span of about an inch. He emerges from his bag, flies to a female, mates, and dies in a few days. Mating usually occurs during the fall in Alabama. Females lay a mass of 500 to 1,000 eggs in their bags and then die. These eggs overwinter and hatch in the spring. Larvae begin to feed and make bags soon after hatching. Small larvae feed on upper leaf surfaces. As the larvae grow, they enlarge their bags and move to lower leaf surfaces. Full grown larvae have bags from 1 to 2 inches long. During late summer to early fall, larvae pupate in their bags, and adults emerge in a week or two. There is one generation a year. Bagworms are commonly found from the Atlantic states westward into Texas, Oklahoma, and Kansas and north into Illinois and Ohio.

Bagworms (Order Lepidoptera, Family Psychidae, Tryridopteryx ephemarae- formis Haworth). A, male moth, 1-inch wing span; B, female remains in bag; C, larva feeds in spindle-shaped bag on deciduous and evergreen foliage. Host Plants Narrow-leafed evergreens such as junipers, Arizona cypress, cedars, and arborvitae are favorite foods of bagworms. Occasionally, bagworms are found on hardwoods.

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Damage

Bagworm caterpillars damage plants by eating the foliage. Some evergreens do not fill in the defoliated area with new growth, so often the desirable appearance of the plant is altered. Severe defoliation may result in plant death.

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Control

Homeowners can effectively control bagworms by hand-picking the bags from infested plants during the winter or before the eggs hatch in the spring.

Chemicals can be used to control bagworms if applied early in the spring (May) or summer (June) while the caterpillars are small. Large bagworm caterpillars are difficult to kill. The following insecticides can be used by homeowners for bagworm control.

Insecticide	Amount To Use/Gallon
acephate Orthene Turf, Tree, and Ornamental Spray	3 teaspoons
Bacillus thuringiensis, such as Dipel WP	See label
chlorpyrifos (Dursban)	See label
diazinon 25 EC	2 teaspoons
malathion 57% EC	2 teaspoons

Note: EC=emulsifiable concentrate; WP=wettable powder

Use pesticides only according to the directions on the label. Follow all directions, precautions, and restrictions that are listed. Do not use pesticides on plants that are not listed on the label.

The pesticide rates in this publication are recommended only if they are registered with the Environmental Protection Agency and the Alabama Department of Agriculture and Industries. If a registration is changed or cancelled, the rate listed here is no longer recommended. Before you apply any pesticide, check with your county Extension agent for the latest information.

Trade names are used only to give specific information. The Alabama Cooperative Extension System does not endorse or guarantee any product and does not recommend one product instead of another that might be similar.