THE LEPIDOPTERA 



261 



mixed with hairs from the body of the caterpillar and are gray in color. 

 The female on emerging from the pupa stage crawls to the surface of 

 the cocoon and later lays there from 300 to 500 eggs (Fig. 265) which she 

 then covers with a white froth which soon hardens and forms a crust 

 covering and hiding the eggs. This white crust on the gray background 

 of the cocoon and the generally dark bark of the tree makes the eggs very 

 conspicuous objects. 



The eggs soon hatch and the caterpillars thus produced feed on the 

 leaves until full-grown (Fig. 266) then pupate as in the preceding genera- 

 tion and the moths appearing later, also lay their eggs on their cocoons 

 and cover them with white froth. It is probable that throughout the 



Fig. 265. 



Fig. 266. 



Fig. 265. — Adult female of the White-marked Tussock Moth with an egg mass covered 

 by a white crust, resting on her cocoon. About natural size. {Modified from N. Y. Agr. 

 Exp. Sta. Bull. 312.) 



Fig. 266. — Caterpillar of White-marked Tussock Moth. Note the four "tussocks" of 

 hairs. Slightly reduced. (Modified from N. Y. Agr. Exp. Sta. Bull. 312.) 



northern part of the territory inhabited by this insect, these eggs will be 

 laid so late in the season that they will not hatch until the following 

 spring and the white crusts covering them will therefore be prominent 

 objects during the winter. We accordingly find two generations of this 

 insect in the Middle States; one in the North, and there are probably 

 three in the South, corresponding to some extent at least, with the 

 length of time during which food is available. 



The moths are seldom seen, though the males fly somewhat during 

 the day. The egg clusters, however, are objects which attract attention 

 and the caterpillars are highly colored and so peculiar in appearance as 

 to be very noticeable. A full-grown caterpillar is nearly an inch and a 

 half long, with a bright red head and also two red humps above, near the 

 hinder end. Between the head and the middle of the body is a row of 

 four large cream-colored tufts or "tussocks" of hairs standing up some 

 distance above the surface of the body. The side is grayish with a yellow 

 band above and below. Projecting upward, forward and outward from 

 just behind the head are two slender clusters of black hairs or "pencils" 



