90 TRUE TUSSOCK-MOTHS. 
A narrow black or brown stripe extends along the back, and 
a wider dusky stripe on each side. The peculiar cup-like, 
coral-red protuberance already mentioned are scent-organs 
used by the caterpillars to drive off enemies; they are used in 
a similar way as the whip-like organs found in the caterpil- 
lars of the swallow-tailed butterflies described before. As 
soon as the caterpillars reach their full size they descend to 
the trunk, or move to tree-boxes or fences, to find shelters in 
which to spin their cocoons, which are loosely made of silk 
and their own hair. It is a strange fact that the female 
caterpillar sheds her skin once more than the male. In 
Minnesota we have but one annual brood, at least in St. 
Paul and Minneapolis; further southtwo broods are the rule. 
The brownish pupz of the two sexes differ very consid- 
erably, the male being much smaller than the female; both 
are covered with short hairs. 
The moths differ still more, the male being winged, 
with very broad and feather-like antenne, while the 
female is wingless, possessing slender antennz. The fe- 
male is simply provided with the merest rudiments of 
wings, which are perfectly useless; her body is of a light- 
gray color, oblong-oval, with long legs, and is greatly 
distended with eggs. After leaving the pupal shell she 
does not leave the outside of the cocoon, but patiently 
awaits the male, when, after pairing, she commences to 
deposit her eggs in the manner already described; during 
this process her body shrinks more and more, and finally 
‘she drops down to the ground and dies as soon as her work 
is finished. The male moth is of an ashen-gray color; the 
fore-wings are crossed by wavy bands of a darker shade. 
There is a small black spot on the outer edge near the tip, 
an oblique blackish stripe beyond it, and a minute very 
characteristic white crescent near the outer hind angle. The 
gray body has a small black tuft near the base of the 
abdomen. The wings, when expanded, measure about an 
inch and a quarter across. 
