LAWSON: KANSAS CICADELLID^. 115 



KEY TO SPECIES. 



A. Head broadly foliaceous, elytia more than half the length of the 

 abdomen in both sexes. platyrhynchiis. - 



AA. Head narrowly foliaceous, elytra less than half the length of the 

 abdomen in both sexes. vandiizei. 



Dorycephalus vlatyrJujnchus Osb. 



Dori/cci'linliix s/j.. Osb., Proc. la. Acad. Sci., i, pt. 2, p. 127, 1892. 

 Dorj/rephalii.i plntj/rliiiucliii.s Osb., Can. Ent., xxvi, p. 216, 1894. 



Dorycephalus platyrhynelms O. & B., Pror. la. Acad. Sci., p. 185, pi. 20, fig. 1, 1897. 

 Dorycephalus platyrhynchiis Ball, la. Acad. Sci., for 1899, p. 68, 1900. 

 Dorycephalus platirrhynchiis Osb., U. S. Dept. Agr., Div. Ent., Bui. 108, p. 65, fig. 7, 

 1912. 



Dorycephalus plafinhynrlius Van D., Cat. Hemip. N. A., p. 623, 1917. 



Form: Long forms, characterized by the very broad, flat head. Length, 

 female, 14.5 mm.; male, 9 mm. Female, vertex about twice as long as 

 width across eyes, very flat and with a longitudinal median carina. Pro 

 thorax more than twice as broad as long, with five elevated longitudinal 

 ridges, anterior margin sinuate, lateral margins long and parallel, po& 

 terior margin emarginate medially. Elytra strongly veined, extending' 

 to fourth abdominal segment, or longer, extending to last segment, leav- 

 ing only a part of the pygofers and ovipositor exposed. Abdomen long 

 and tapering, ending in a long ovipositor. Male, vertex shorter, elytra 

 long, equalling the tip of the pygofers. 



Color: Female, pale yellow, with carina on vertex darker, the dark 

 stripe sometimes extending on to the middle of the pronotum and the 

 scutellum. Lateral portions of vertex and pronotum often mottled with 

 brown. Visible abdominal segments with a pair of usually basal brown 

 spots dorsally. Males darker, grayish-brown, vertex and pronotum 

 mottled with brown in addition to the median dark line. 



External genitalia: Female, last ventral segment longer than preced- 

 ing, posterior margin truncate, somewhat sinuate, with a small, but dis- 

 tinct, rounded median tooth; pygofers very long, tapering from broad 

 base to acute apex, much exceeded by the very long and stout ovipositor. 

 Male, valve small, just visible from under the large last ventral segTnent; 

 plates at base about half the width of the last ventral segment, tapering 

 rapidly to the long and slender apices; pygofers broad at base but taper- 

 ing regularly to acute apex, the two together forming a triangle about 

 twice as long as the plates, bearing a scant covering of short hairs. 



Distribution: Taken only in Gove and Sumner counties but 

 should occur throughout the state. 



Hosts: Osborn and Ball give Ehpnus canadensis and virgini- 

 cus as the chief grass hosts. It also occurs on Aristida. 



