16 U.S. NATIONAL MUSEUM BULLETIN 261 



family which includes the smallest of the leafhoppers. It is proposed 

 here to include only the tribes Proconiini and Cicadellini in the sub- 

 family. The higher category based on Makilingia is considered to be 

 of subfamily status and will be so treated by me in another paper. The 

 tribe Mileewanini is more closely related to the subfamily Typhlocy- 

 binae than to the Cicadellinae and has been removed from the Cic- 

 adellinae to the Typhlocybinae by me (1965a). Oman's (1949a) place- 

 ment of the Evacanthini in the Cicadellinae is not followed here; 

 this group is considered at this time to be of subfamily status. The higher 

 category based on Errhomenellus Puton is also here regarded as of sub- 

 family status. 



After the above changes have been taken into account, the subfamily 

 Cicadellinae may be characterized as follows: Leafhoppers with the 

 ocelli located on crown, nearly always closer to the posterior margin 

 than to apex or to anterolateral margin (exception: some species of 

 Mesogonia); species usually not flattened dorsoventrally; forewing with 

 outer margin of inner apical cell parallel to long axis of wing; posterior 

 tibiae with macrosetae in four regular rows; proepisternum exposed; 

 lateral clypeal sutures extending onto crown and almost always ex- 

 tending to or near ocelli. This subfamily includes taxa from all of the 

 zoogeographical regions of the world. It is especially rich in species 

 from the Neotropical region, relatively poor in species from North 

 America and from Africa; in Europe it is represented by only one genus 

 with a single species. 



The key to tribes (p. 1 7) , although it is the best I have been able to 

 devise, will not work for all specimens. Difficulties arise chiefly as a re- 

 sult of intraspccific variation; for example, in the genera Keonolla, 

 Neokolla, and Manzutus in the Cicadellini, where a single species may 

 include specimens which violate the hind knee-proepimeron character 

 and also have antennal ledges which are not protuberant. 



The genera included by Mctcalf (1965a)j but not treated here, are 

 excluded from the Proconiini; they will be dealt with later. Certain 

 species included by Metcalf in the genera treated in this part of this 

 study are not here included ; these will be treated later, either in new 

 combinations or as species of uncertain position. Only 16 species 

 presendy remain completely unknown to me. 



Certain species have been incriminated as plant virus vectors, the 

 greatest number from North America, where Oman (1949a:ll) re- 

 ported 15 species of the subfamily, as restricted here, to be vectors of 

 three plant diseases. It should be kept in mind, howe\er, that relatively 

 few species occur in America north of Mexico, and that much more is 

 known about these than of the great majority of cicadelline leafhoppers. 

 Turner and Pollard have published (1959a) the results of years of study 



