Anisota virginiensis (Drury) (Saturniidae)
L.L Hyche, Associate Professor
Department of Entomology & Plant Pathology
This species occurs throughout the eastern half of the United States into adjacent southern Canada. The caterpillar (Photo 1) feeds primarily on foliage of oaks but has been reported to feed on maple, birch and hazel. In Alabama it is found on various oaks.
Life Cycle, Description, and Habits
The oakworm overwinters as a pupa (Photo 2) in the soil. Adults emerge in June. The moth (Photo 3) is brownish red with a purplish tint, especially on the front wings. Each front wing has a small but conspicuous white dot and a median transparent area.
Eggs are laid in clusters on the undersurface of leaves. Newly hatched to mid-stage larvae feed in groups (Photo 4); late-stage and full-grown larvae tend to separate. The full-grown caterpillar (Photo 1) is brownish to grayish green, and about 50 mm long. The head is olive green (early stage larvae have black heads, Photo 4) and the body is speckled with numerous white granules. There are two prominent long black spines on the second segment behind the head, and rows of short spines down the back and along the sides of the body. There are two pink lines down the back and one on each side below the spiracles. The spiracles are black.
Occurrence, Damage, Importance
The pinkstriped oakworm is fairly common but not often abundant. Caterpillars have been found in Alabama from mid-June through September; two broods occur, June-July and August-September. Infestations most often encountered are small and seem to amount to brood from one or two egg masses. Most infestations are found on open-growing shade, street, and ornamental oaks. On large full-crowned trees, defoliation is usually limited to one or two branches; however, the caterpillars are aggressive feeders and brood from a single egg mass can completely strip small trees. Complete loss of foliage may result in loss of growth and dieback in crowns. For the most part, damage is aesthetic, and the oakworm is primarily a pest in the urban forest.