STUDIES OF THE SPECIES IN THE GENUS CICADELLA 



LATREILLE (HOMOPTERA) OF NORTH 



AMERICA, NORTH OF MEXICO. 



Chris E. Olsen, 



West Nyack, N. Y. 



In working over the species in the genus Cicadella, which 

 from time to time had gathered in the writer's collection and in 

 collections loaned for study, it was found impossible, from the 

 present literature, to determine and properly place all the 

 forms at hand. Some of these closely related and undescribed 

 forms obviously caused considerable confusion at times and it 

 became evident that a review with further study was quite 

 necessary. 



In reviewing this genus the author was confronted by sev- 

 eral intricate questions. These questions were communicated 

 to and discussed with other scientists interested in this partic- 

 ular genus. In some of these communications the main points of 

 the author were sustained and a good deal of encouragement 

 was given, while in one or two cases it was pointed out that his 

 views were probably misguided. In such cases of doubt these 

 views were dropped for possible further consideration and study. 



Liberal use has been made of "sub-species" in place of 

 "variety"; all forms which show a more or less constant dis- 

 tinction from the typical species, and which it would not, by 

 structural characters, be safe to call species, although in some 

 cases they may be such, are placed as sub-species. All others, 

 more or less varying in color combinations and designs from the 

 typical form, have been given a varietal name where such was 

 deemed advisable for the purpose of identification. In this 

 paper little use is being made of external genital characters for 

 the reason that where the differential characters were mostly 

 wanted the genital differences were too small or too variable to 

 depend on, and preference was given to other structural char- 

 acters, color designs, and patterns. 



^The "Reivew of the Tettigonidce'' by Ball, 1901, has been 

 taken as basis for this study. This valuable work, which was 

 published twenty years ago, is today still indispensable for the 



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