The Puss Caterpillar. 3 



THE LAKVA. 



Tlie first instar is about 1.5 millimeters long. The color is usually yelloTvish with a 

 slight reddish tinge. Each of the body segments is pro\T.ded with protuberances on 

 each side crowned with hairs, some of which are one-half to two-thirds the length of 

 the body, and among these hairs occur rather strong spines. These spines are only 

 slightly developed on the posterior segments. In the second instar the length of the 

 larva is about 2.3 millimeters, the color usually rather uniformly reddish yellow, the 

 greatest width at the anterior thoracic segment and tapering toward the posterior end. 

 The body is fairly well covered with tufts of rather long hairs intermixed with other 

 hairs somewhat wavy and often equal in length to the body. In the third instar the 

 larv'ae measure 3.1 millimeters in length. The hau-s appear longer, more numerous, 

 and rather lighter in color than in the previous instar. In the fourth instar the larvae 



Fig. 2.— Female moth of the puss caterpillar. 



measure about 3.6 millimeters in length. The hairs are more thickly set than in 

 earlier stages and are inclined to recur^•e, especially in the middle of the body, gi^^ng 

 a matted or bunched appearance. There is apparently an increase in the number of 

 urticating spines with each molt. 



It is believed that there are five or six instars, but owing to high mortality and over- 

 lapping the later stages have not been definitely se]5arated. In the last stages the 

 larvae are well covered with hair, which lies rather flat, extending downward to the 

 surface upon which the insect rests. The larvae are considerably deeper in the thoracic 

 region and taper toward the posterior end, the hair at that end being tufted to form a 

 sort of tail. (See Fig. 4.) The hairs all arise fi'om rather definite circlets, three rows 

 of which are present on each side, the dorso-lateral ones being the largest. Among the 

 hairs on each of these convex areas are numerous smooth yellowish spines with almost 

 black tips. (See Fig. 5.) The dorso-lateral rows contain from 100 to 125 each, the 

 lateral from 50 to 60, and the ventro-lateral rows 20 to 30 each. Close to the base of 

 the legs and the pseudopods is a row of small folds bearing some hair on their apexes, 

 but apparently not pro^dded with spines. The length of the mature larva is about 1 

 inch. 



