1913] Wing Veins of Me?nbracidcB 77 



MATERIAL 



Nymphs 

 About twenty species of the Membracidee, representing 

 eight genera of fairly wide distribution as regards relationship 

 are common to the local fauna of Ithaca, New York, the nymphs 

 of most of which are easily obtainable. These have been used 

 for the determination of the nymphal tracheation. The choice 

 of the various species studied has depended largely upon the 

 characters of the adult wings. In cases of closely related forms 

 where the venation was practically identical and no special 

 problems were involved, the nymphs of a representative species 

 only have been thoroughly worked not, except for the solution 

 of certain questionable points. Some nymphs, also, owing to 

 the form of the wing yield much better preparations than others, 

 and these have been more elaborately figured where general 

 characteristics only were being considered. Some have been 

 discarded because of lack of positive identification and others 

 because of the fact that they were less abundant and illustrated 

 no features not found in forms more easily procured. The 

 bulk of the work has been done from nymphs of the following 

 genera: Ceresa (bubalus, diceros and constans), Thelia {bimacii- 

 lata), Telemona {ampelopsidis), Vanduzea (arquata), Campylen- 

 chia (ciirvata) and Enchenopa {binotata). Altogether several 

 thousand dissections have been made and each point in trachea- 

 tion has been as carefully verified as possible. No attempt has 

 been made to breed the insects since extensive field notes on 

 the habitat, hosts, life-history and general biology of the local 

 forms has made it possible to procure the nymphs at various 

 stages without particular difficulty. 



Adults 

 Besides the forms represented in the local fauna, the wings 

 of all other species procurable have been studied with the view 

 of obtaining a large number of types of venation. The writer 

 is greatly indebted to the Entomological Department of Cornell 

 for the privilege of examining the wings of all the species in the 

 excellent collection of the University, which includes many 

 forms that could not otherwise have been obtained. Thanks 

 also are due to Dr. J. C. Bradley and to Mr. C. R. Plunket for 

 the use of specimens from their collections. 



