Biology of the Membracidae of the Cayuga Lake Basin 343 



occurs in the Membracidae it appears in the hind leg rather than in either 

 of the others. 



The tarsi are much given to pubescence and hairiness. In some species 

 this development is so remarkable as to be used in diagnosis, and unusual 

 development of spines has been used as a generic character for the genus 

 Antianthe (Fowler, 1894-97:137). In the subfamily Centrotinae the 

 bristles, spines, or hairs are so numerous in many species as to completely 

 hide the other structural characters of the tarsus. 



Aside from its use as the distinguishing character of the subfamily 

 Hoplophorinae, the tarsus has been little used for systematic purposes 

 in the study of the Membracidae. There is little doubt but that enough 

 variation exists to warrant more careful consideration of this part of the 

 leg, and a further study of the hind tarsus may yield good taxonomic data. 



the abdomen 



The abdomen consists normally of eleven segments, of which the first 

 is only partially developed and the last two are more or less modified. 

 The arrangement and number of segments is perhaps best shown in the 

 nymph, in which the anal region is represented by a series of telescoping 

 tubes (Plate xxxvii, 5). In this stage the first segment is hidden under 

 the metathorax and the last is poorly developed, but the others are evident. 

 In the adult the abdomen of the insect is so modified in the separate 

 sexes as to require separate descriptions. The following general facts, 

 however, may be noted. 



Each segment from the second to the seventh, inclusive, is ring-like 

 in form and consists of a distinct tergum, pleuron, and sternum. The 

 first segment consists of a tergum only (Plate xxxvii, 4), and this sclerite 

 is only partially developed, the lateral extremities being shortened. The 

 abdominal terga are long, horseshoe-shaped sclerites covering not only 

 the dorsum but most of the lateral areas. They end in rather a sharp 

 angle at the junction of the pleura. The pleura are short and sub- 

 rectangular (Plate XXXVII, 1), and are located on the ventral rather than 

 the lateral part of the abdomen. The first eight abdominal pleura bear 

 spiracles in the extreme cephalic mesal angle of the sclerite. The spiracle 

 for the first segment is, indeed, not in the chitinized part of the sclerite 

 at all, but is located in the membrane between this sclerite and the meta- 

 thorax in such a position that it appears as a part of the latter segment.,. 



