Studies on Life-history of Bombycine 3Ioths. 8T 



described, having an entirely black head and measuring 15 mm. in 

 length, molted September 29th, and assumed a red head; and hence, 

 as I am sure my first three stages are as above described, I feel 

 quite confident that there must be five stages before the last, and 

 that the fifth stage, next to be described, is the one in which the 

 insect hibernates. The following description is taken from several 

 specimens observed June 22d and later in the summer of 1890; my 

 living one, just molted, being somewhat dwarfed. At first the 

 head is entirely light chestnut-red, and the abdominal legs are of 

 the same color. 



Stage V. — Length 18 mm. The head light chestnut-red, becom- 

 ing blackish in front. Body densely hairy, the head and body when 

 not moving completely concealed by the dense stiff" hairs, which are 

 of even length. Those overarching the head and those on the sides 

 of the body are coal-black. The verticils on the prothoracic seg- 

 ment and 9th abdominal segments are snow-white, and white hair? 

 are mixed with the black ones on the sides. The dorsal hairs bright 

 sulphur-yellow. There is a series of nine dorsal double median black 

 tufts, the first pair of which are slightly larger and higher than the 

 others, and directed a little forwards, while the last pair are directed 

 obliquely backwards. 



A broad, irregular brown, somewhat scalloped white subdorsal 

 line, while the infraspiracular line is decidedly narrower ; it is scal- 

 loped or wavy and is bright snow-white, besides being much more 

 distinctly seen than the subdorsal one. 



In this stage it continues to feed conspicuously on grass, both in 

 June, and the second brood in September, hibernating in this stage. 

 It transforms into the last larval stage as early as June 24th, and 

 in the summer of 1890, which was very favorable to caterpillar life, 

 the full-grown larvae were observed as late as July 21th. 



Summary of Length of the different stages. — Egg stage 11 to 13 

 days; larva, 1st stage 10 days; 2d stage 10 to 12 days; 3d stage 

 5 to 6 days; 4th stage? 23 days; 5th stage from late in September 

 to late in June; prepupal stage 3-4 days; pupal stage 28-30 days, 

 imago stage probably about two or three weeks. 



Recapitulation of the more salient larval features. 



1. As in Arctians and Lithosians no glandular hairs in stage I. 

 Body and hairs as in Arctians. A well-developed prothoracic chiti- 

 nous shield and suranal plate in stage I. 



