Adults are present from early July to early August in the Lake States. Eggs are 
usually deposited in small, irregular clusters on or near the female pupal case, 
mostly on the needles near midcrown but also on the trunk, dead twigs, and similar 
vegetation. Young larvae feed on the flat surfaces of needles. During August, the 
second or third instars spin a few silken threads about themselves and go into 
hibernation. They may be found beneath rough bark on large trees or between the 
bases of needles on young, smooth-bark trees. Feeding is resumed in the spring on 
staminate flowers and young needles. Later, old needles are also attacked, with 
everything being consumed down to the needle sheath. In heavy infestations, the 
entire tree may be completely defoliated. Full-grown larvae spin silken cocoons on 
twigs or among needles. There is one generation per year (/237). 
Several extensive outbreaks have occurred in the Lake States since the turn of the 
century, and losses, especially of jack pine, have been serious. During 1961-62, 
outbreaks covering several hundred square kilometers of jack and red pines and 
white spruce were recorded in the region. 
Other eastern species of Dasychira and their hosts are as follows: D. plagiata 
(Walker)—on conifers at high elevations in the Appalachians, northern Mas- 
sachusetts into Canada and west to the Rocky Mountains (//43); D. obliquata 
(Grote & Robinson) and D. vagans (Barnes & McDunnough)—a willow and poplar 
defoliator; D. meridionalis (Barnes & McDunnough)—on oak in the Southeast; D. 
cinnamomea (Grote & Robinson)—on elm from New England to the Lake States; 
D. tephra Hubner—on oak in the Southeastern States; D. dorsipennata (Barnes & 
McDunnough)—on oak in Maine and southern Canada. 
The gypsy moth, Lymantria dispar (L.), was introduced into the United States in 
1869 when a French scientist brought a number of egg clusters from France for the 
purpose of crossing the species with the silkworm. During the course of his work, 
larvae escaped, and the species became established. About 20 years later, cater- 
pillars had spread over an area of about 900 square kilometers around Boston, and 
shade and fruit trees were being completely defoliated. The gypsy moth has 
continued to spread and now occurs throughout the New England States, except 
northern New Hampshire and Maine, and northeastern Vermont. It also occurs in 
New Jersey, New York, Pennsylvania, Delaware, Maryland, Michigan, Virginia, 
and southern parts of Ontario and Quebec. Relatively small, isolated infestations 
have occurred in Arkansas, California, Illinois, Nebraska, North Carolina, Oregon, 
and Wisconsin. Adult males have been trapped in numerous other States. [ts hosts 
include most species of hardwoods, the oaks, apple, basswood, willows, birches 
(except yellow and sweet), and poplars being most highly favored. Several conifers 
are also attacked, usually when growing in mixture with the more highly favored 
hardwoods (42). A list of food plants, divided into groups by host preference, has 
been published (593). 
The general biology of the gypsy moth has been reported by several authors (/6, 
727, 928). The male of the gypsy moth (fig. 101A) is dark brown, with blackish 
bands across the forewings, and has a wingspread of about 37 mm. Females (fig. 
101B) are almost white and have wingspreads of about 50 mm. The abdomen of the 
female is clothed in yellowish hairs and is so large and heavy that she is unable to 
fly. Full-grown larvae (fig. 101C) 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 
five pairs of blue spots followed by a double row of six pairs of red spots on the 
dorsum. The pupa (fig. 1O1E) is reddish brown with a sprinkling of reddish hairs. 
229 
