wingspreads of about 50 mm. The female abdomen is clothed in 
yellowish hairs and is too large and heavy for her to fly. Full- 
grown larvae (fig. 123 D) are about 37 to 60 mm. long. The head 
has yellow markings; the body is dusky or sooty-colored and 
hairy; and there is a double row of 5 pairs of blue spots, followed 
by a double row of 6 pairs of red spots, on the dorsum. The pupa 
(fig. 123 C) is reddish brown with a sprinkling of reddish hairs. 
Adults appear and mate in late July and August. The males fly 
vigorously in a zig-zag manner, often within a few feet of the 
ground on warm days. 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. 123 E) 
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. 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 towards the 
tops of trees in search of foliage. During this period they often 
spin down on silken threads, especially when disturbed, and some 
may be transported considerable distances by the wind (147). 
Newly-hatched larvae feed first on leaf bases, then on the leaf sur- 
faces, chewing small holes in the leaves. Older larvae feed al- 
most 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 (259). Large larvae consume 
entire leaves, except the larger veins and midribs. In heavily 
infested stands the entire crop of foliage may be consumed be- 
fore the larvae reach maturity. When this happens, tne larvae 
usually vacate the trees and often migrate considerable distances 
in search of food. In heavily defoliated stands when the food 
supply is depleted but not completely consumed before the larvae 
reach maturity, many succeed in pupating although they are 
smaller than normal in size. This results in smaller than normal 
adults, and the number of eggs deposited per female is greatly 
reduced. Larvae seek sheltered places in which to pupate. Pupae 
may be found attached by silken threads to limbs and trunks of 
trees, stones, forest debris, and the like. In neavy infestations, 
they are often found massed together in large numbers. The 
pupal stage lasts about 10 days or 2 weeks. 
The gypsy moth has long been considered one of the most im- 
portant forest insects in the United States. Enormous sums of 
money, probably in excess of 100 million dollars, have been ex- 
pended since the turn of the century by the Federal Government 
and the States involved to suppress it and to prevent its further 
spread. In 1923, a “barrier zone” from 25 to 30 miles wide and 
about 250 miles long, was established from Long Island to the 
Canadian border to prevent further western spread of the spe- 
cies by intensive eradication efforts (121). Despite these efforts, 
outbreaks have continued to occur in the older infested portions 
of New England, some of which covered tremendous areas, and 
extensive infested areas occur west of the barrier zone. In 1945, 
322 
