LAWSON: KANSAS CICADELLID^. 63 



KEY TO SPECIES.* 



A. Vertex ^\'ith two round black spots. 



B. Spots on vertex large, scarcely more than their own diameter 

 from the eyes. 



C. Without black spots en pronotum and scutellum. 



D. Clavus unicolorous. fitchi. 



DD. Basal half of clavus bright yellow. 



provancheri. 

 CC. With black spots on pronotum and scutellum. 



cratsegi. 

 BB. Spots on vertex small, two or more times their own diameter 

 from the eyes. 



C. Nervures of elytra not distinctly alternating in color; 

 outer anteapical cell, if present, triangular. 

 D. Green forms, dark line along sutural margin of 

 elytra. snowi. 



DD. Brown forms, without dark lines on sutural margin 

 of elytra. ramentosus. 



CC. Nervures of elytra usually alternately light and dark, 

 outer anteapical cell long and narrow. 

 D. Cross nervure between first and second sectors 

 broadly white. moniliferx. 



DD. Cress nervure between first and second sectors not 

 broadly white. 

 E. Species larger, 5 mm. or over, darker; male 

 ante'nn* with moderate discs on longer fila- 

 ments, altemiatus. 

 EE. Species smaller, 4. .5 mm. or less, lighter; male 

 antennae with very large discs on very short 

 filaments. verticis. 

 AA. Vertex ^vithout round black spots. 



B. With dark band on sutural margin of elytra. suturalis. 

 BB. Without dark band on sutural margin of elytra. 

 C. Size large, over 5 mm. long. 



D. Outer anteapical cell present, male antennal discs 

 large. palUdus. 



DD. Outer anteapical cell absent, male antennal discs 

 very small. duzeei. 



CC. Size smaller, less than 5 mm. long, elytra hyaline, show- 

 ing dark nervures of the wings. tiet'vatus. 



Idiocerus fitchi Van D. 



Idiocerug fitchi Van D., Can. Ent., .\li, p. 383, 1909 (n. n. for maculipeimis Ph.). 



Idiocerus maculipennis Fh., Homop. N. Y. St. Cab., p. 59, 1851. 



Bythoscopus maciilipi'nni-'i W'alk.. List Homop., TV., p. 1161, 1852. 



Idiocerus macuHpennis Van D., Psyche, V, p. 388, 1890. 



Idiocerus maculipennis O. & B., Proc. Dav. Acad. Sci., VII, pp. 73, 127, 1898. 



Idiocerus maculipennis Osb., 20th Rept. N. Y. St. Ent., p. 507, 1905. 



Idiocerus fitchi Britt. & Saund., Can. Ent., xlix, p. 149, pi. IX, 1917. 



Idiocerus maculipennis Van D., Cat. Hemip. N. A., p. 580, 1917. 



Idiocerus maculipennis Nic, Ent. News, XXX, p. 277, 1919. 



* Adapted from Osborn and Ball, Proc. Dav. Acad. Sci., VII, p. 125, 1898. 



