LAWSON: KANSAS CICADELLID.^. 63 



KEY TO SPECIES.* 



A. Vertex with two round black spots. 



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

 from the eyes. 



C. Without black spots on 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. moniliferss. 



DD. Cross nervure between first and second sectors not 

 broadly white. 



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

 antennae with moderate discs on longer fila- 

 ments, alternatus. 



EE. Species smaller, 4.5 mm. or less, lighter; male 

 antennae with very large discs on very short 

 filaments. verticis. 



A A. Vertex without 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. 'pallidxis. 



DD. Outer anteapical cell absent, male antennal discs 

 very sm.all. duzeei. 



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

 ing dark nervures of the wings. nervatus. 



Idiocei'Ms fitchi Van D. 



Tdiocerus fitchi Van T)., Can. Ent., xli, p. 383, 1909 (n. n. for maciilipeunis Fh. ). 



Jdiocerus macuttpennis Fh., Homop. N. Y. St. Cab., p. 59, 18.51. 



Bythoscopus niaculipfinni-i Walk., List Homop., IV., p. 1161, 1852. 



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



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



Idiocerus maculipennis Osb., 20th Kept. 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 Bali, Proc. Dav. Acad. Sci., VII, p. 125, 1898. 



