1934] A Psychid New to North America 21 
turn, near Germantown, Pennsylvania; females from this 
colony readily mated with Massachusetts males; many of 
the older plantings in the Morris Arboretum are said to 
have originated in the Arnold Arboretum, which may ex- 
plain the mode of introduction. A third colony is indicated 
by empty cases, apparently identical with those of Fumea, 
found by Dr. W. T. M. Forbes in Bancroft Woods, in Wor- 
cester, Massachusetts. Other colonies are to be anticipated. 
Larva and Case . The larvae hatch during June and early 
July, and at once each individual constructs a small silken 
case, or “bag,” in which, enlarged from time to time, it 
spends its entire larval and pupal period. This elongate bag 
is adorned on the outside with bits of grass and other 
ground debris, longer pieces being attached lengthwise and 
often projecting slightly beyond the posterior end of the 
bag. Through an anterior opening, the larva is able to thrust 
out its head and thorax for purposes of feeding, moving, or 
working on the case; the posterior end of the case has a 
smaller opening, usually collapsed but readily opened from 
within for the expulsion of excrement. During resting and 
molting periods the anterior edge of the bag is firmly at- 
tached by silken threads to some object of support. 
Food is taken only during the larval period, and consists 
chiefly of grasses, mosses, lichens, and other low plants, al- 
though the insect may occasionally exhibit carnivorous 
tendencies, as evidenced by feeding on scale insects and, in 
the laboratory when very hungry, on the living larvae and 
helpless adult females of its own species. 
As in many other members of this family, the larval pe- 
riod is very protracted (Fig. 2 )— occupying approximately 
eleven months— and growth is correspondingly slow. From 
the time of hatching in June or July until the onset of win- 
ter, the larval case attains a length of but three millime- 
ters. Hibernation takes place in crevices in the bark of 
tree trunks, or beneath stones, branches of trees, and other 
objects resting on the ground. In the spring, feeding is re- 
sumed, and growth is more rapid. When the larvae are ma- 
ture, in late May and early June, the cases of the females 
are generally larger than those of the males. Measurements 
of fifty female cases at this time, inclusive of the loose ma- 
