8 



four or five weeks. The number of eggs laid by a single hiber- 

 nated female has not been determined ; but, from specimens kept 

 in confinement in the fall, an average of between fift}- and sixty 

 was obtained, the highest number recorded being seventy-two. 



The length of the egg stage varies much, according to atmos- 

 pheric conditions. The eggs laid by the hibernated females hatched 

 in from ten to fifteen days, but this period is shortened in the sum- 

 mer generations to from four to seven days. 



Larva. (Plate /., Fig. 1.) 



As the young larva emerges from the leaf, it works its way up 

 until about four-fifths of its body projects above the surface. 



The body is very soft, shiny and nearly white. The eyes are 

 purplish red in color, and the ocelli are wanting in all the larval 

 stages. The antennae and legs are folded closely against the ven- 

 tral side of the body, and their outlines and segmentations are very 

 indistinct. The larva remains supported in an upright position by 

 the tip of its abdomen while the body is drying and the legs and 

 antennffi are being separated from the body. After waviug these 

 in the air for a short time, the tiny larva falls forward upon its 

 feet and pulls itself entirely free from the tissue of the leaf. It is 

 able to travel immediately, and usually moves a little way from 

 the egg before stopping for a short rest, after which it begins 

 feeding. 



The length of the larva very soon after its emergence is about 

 .3 mm., and its width about .1 mm. The body is cylindrical, 

 tapering posteriorly from the eighth abdominal segment. The 

 head is nearly as wide as the thorax. The antennae are compara- 

 tively large, approximate at their base, and composed of seven 

 segments, of which the last four are closely joined and appear 

 almost like a single conical segment. The fourth segment is 

 larger than any other, and is distinctly ringed with whorls of mi- 

 nute setae, while the second and third are indistinctly ringed. The 

 basal segment bears one small spine on the inner side, the second 

 segment four short spines which are directed forward and one very 

 long spine directed backward toward the head. The third segment 

 bears five short spines, and the terminal part of the fourth and 

 each of the following segments a number of spines which are quite 

 long and stout. The legs are stout, the tarsi one-segmented and 

 terminated by two claws, and the bladder-like expansion of the 

 adult is present. The abdomen is composed of ten segments 

 which are much compressed longitudinally, and, except the tenth 

 segment, are marked with six longitudinal rows of setae, three 

 pairs to each segment. The four dorsal rows also extend forward 



