D x. 
F-489191-95 
Figure 101.—Life stages of the gypsy moth, Lymantria 
dispar: A, adult male moth; B, adult female moth; C, 
mature larva; D, egg mass; E, female pupa with cast 
larval skin. 
Adults appear in late July and August, and mate. The males fly vigorously in a 
zigzag manner, often within about | m of the ground. The females, being unable to 
fly, crawl a short distance from the empty pupal case and mate. Immediately after 
mating, they lay their eggs in oval masses (fig. 101D), about 100 to 1,000 eggs 
each, then cover them with buff-colored hairs from their abdomens. While the 
majority of the masses are deposited on the trunks and limbs of trees, many are also 
laid in various other places such as under stones, inside hollow stumps and trees, on 
leaves, and even on buildings. Some masses are deposited on vehicles, and this 
accounts for the long-distance dispersion of the gypsy moth. The winter is spent in 
the egg stage, and hatching occurs about the first of May, usually about the time oak 
leaves unfold. 
Young larvae crawl from the egg mass and move toward the tops of trees. During 
this period they often spin down on silken threads, especially when disturbed, and 
some may be transported by the wind (22/, 824). Newly hatched larvae feed first 
on leaf bases, then on the leaf surfaces, chewing small holes in the leaves. Older 
larvae feed almost entirely from the edge of the leaf. During this part of their lives, 
they feed mostly at night and tend to congregate in sheltered places during the day 
(436). Large larvae consume entire leaves except the larger veins and midribs. In 
heavily infested stands the entire crop of foliage may be consumed before the larvae 
230 
