130 FIFTH ANNUAL REPORT 



the base of the h^ttel■. The other spines are somewhat stouter, with the blunt tips from 

 which the bristles spring, more or less white. Characters of mature larva more patent. 

 In the fiftJi stage, the granulations assume the form of whitish transverse-oval papilla;, 

 each emitting from the center a minute dark bristle. These papillas are mostly conflu- 

 ent around the stigmata, and, together with some irregular, pale yellow markings, pro- 

 duce a broad and pale stigmatal stripe. They are most sparse along the subdoi'sal 

 region, just above stigmata, where, in consequence, the body appears darkest. In the 

 sixth stage, at maturitj^ it may be thus described : 



Average length, nearly 2 inches. Color, brown-black. Head, cervical shield, anal 

 plate and legs polished chestnut-brown, the prolegs lighter, and inclining to venetiau- 

 red, with hooks more dusky and the true legs darker, inclining to black at tips. The 

 dorsal fascicled spines, with the exception of a few short, black ones in the center of 

 each bunch, are pale, rust-j^ellow, translucent, the tips mucronate and black ; the other 

 compound spines are black, with the blunt ends more or less distinctly white and ti-ans- 

 lucent (but frequentlj^ crowned with minute black points, as in the tirst stage), and the 

 sharp-pointed spinules arising from them dusky. They are generally enlarged and 

 reddish at base, and an approach to the dorsal fascicles is made in the increased number 

 and yellow color of the basal branches, especially in the subdorsal rows. Stigmata 

 sunken, pale, elongate-oval; venter yellowish along the middle, the legs connected 

 with red, and a reddish spot on the legless joints. 



The above is the normal appearance of the larva in Illinois and 

 Missouri ; but it is quite variable. In some specimens the black pre- 

 dominates to such an extent, even in the sixth stage, that the papillge 

 are not very noticeable, and the lateral yellow band is obsolete;* 

 while in others the yellow papillas predominate over the black, and 

 the lateral band is broad and continuous. The amount of light color 

 in the spines is also very variable. It should also be stated that when 

 just hatched, and after each subsequent molt, the color is at first uni- 

 formly brown ; and that the spines for each coming stage are formed 

 under the skin, and not within the old ones. 



The young hatch with us about the middle of April, and are out 

 sometimes before the leaves are ready for them; in which event, they 

 survive many days without food. At this season they spin a mode- 

 rate amount of web, by which they hold tenaciously to the twigs. 

 They are gregarious, and in traveling have a fashion of following one 

 another closely, and mostly in single file. As soon as the leader finds 

 a suitable leaf, he crawls up the midrib to the tip, and the others follow 

 and crowd each side along the edge. Should the leaf be too small to 

 hold them ail, the last remain on the twig; and— after the more fortu- 

 nate ones have eaten and crowded back upon them — in their turn take 

 the lead. The gregarious habit remains until after the last molt, though 

 the original batch may divide into two or more. In the last stage 

 they separate and scatter. 



This is one of the few larvse which pass through five molts, and 

 it usually comes lo its growth about the end of June, or in about two 

 months from the time of hatching.' 



♦All which Mr. Lintner reared seem to have been dark and without the lateral pale stripe; a fact 

 which led him to question the accuracy of a brief description in the American Entomologist, ("Vol. 1, 

 p. 186;, written by myself. 



