76 



bium. The coxa,. Fig. YL, (ox.) is quite distinct and bears upon 

 its surface several small hairs. The trochanter (tr.), when in the 

 bent position as in the figure forms a triangular shaj-e, but when 

 in motion becomes nearly square; this joint is firmly united to the 

 femur, and is movable Avith the coxa. 



The femur (//'.) is stout but not longer than tlic tibia {ti.), both 

 joints are of good size. The tarsus (ts.) is longer than the tibia, 

 the claw at the end of the tarsus is strong and single, the joints 

 are all furnished with hairs, which, although strong, are not as stout 

 as those on tlie antennae. The two posterior pair of legs are simi- 

 lar in jiroportion and size to the one just described, the metathoracic 

 pair having the joints proportionately larger than the two preceding 

 pairs. 



The nine abdominal segments are quite easily traced, the 

 width is greater at the sides than in the middle of the body, and 

 the decline of the first eight is a gradual depression occurring at 

 the intersection of each segment. The ninth and last segment is 

 smaller than the others and ends in a deep half circular fissure, as 

 in Fig. III. One long and strong spinous hair projects from each 

 side of tlie commencement of the' fissure and these are followed 

 by many shorter and less strong ones, which become in the centre 

 thick and cemented together, at times in one body as seen at e 

 in Fig. Vir. and again these hairs are divided into two or more parts. 



HSiblts. When first hatched the young larvae remain upon the 

 leaf and beside the unhatched eggs of the remainder of the egg- 

 mass, and thrusting their slender setae into the leaf, they commence 

 drawing the sap, which sustains their life. There^is no uniformity with 

 reference to the position assumed l)y the newly hatched insect, 

 neither is there a choice shown for any part of the leaf, whether 

 beside a vein or midway, they remain on the lower side of the leaf 

 and do not settle on the upper side even temporarily. When 

 first hatched there is no appreciable difference between the larvae, 

 they are all of the same bright yellow color before described, but 

 soon after a white substance issues from the body and gives the 

 insects a powdered apijearance. Shortly after red and yellow ones 

 are found. The insects Avhich become red are the males, Fig. VIII. 

 and are of the same length and width as the yelloAv, the appendages 

 are similiar, with the exception of the antennae which have seven 

 joints instead of six Fig. IX. The white coating appears upon these as 

 Avell as on the yellow ones or females. Wlicn the number of insects 

 upon a leaf becomes greater than it can furnish food for, tliose first 



