LAWSON: KANSAS CICADELLIDJE. 



67 



Idiocerus verticis (Say). 



(PI. 4, figs. 4-6.) 



Jaxsus verticis Say, Jl. Acad. Nat. Sci. Phila., VI, p. 308, 1831; Compl. Writ., ii, 

 383. 



Bytltoscop * verticis Uhl., Bui. U S. Geol. Geog. Surv., iii, p. 465, 1877. 

 ertiria Van D., Psyche, v, p. 389, 1890. 

 erticis 0. & B., Hemip. Colo., p. 80, 1895. 

 erticis O. & B., Proc. Dav. Acad. Sci., vii, p. 132, 1898. 

 erticis Osb., 20th Kept. N. Y. St. Ent., p. 507, 1905. 

 rus vertices DeL., Tenn. St. Bd. Ent., Bui. 17, p. 11, 1916. 



Idioc 

 Idioc 

 Idioc 

 Idioc 

 Idioc 

 Idioc 



rvs verticis Van D., Cat. Hemip. N. A., p. 577, 1917. 



Form: The smallest member of the genus in Kansas. Length, 4.25 to 

 4.5 mm. 



Color: Pale brownish to nearly white. Pair of small, black spots on 

 vertex. Pronotum with light-brown markings on disc. Scutellum with 

 basal angles black or brown. Brown nervures of elytra usually inter- 

 rupted with white, dark specimens showing light spot across middle of 

 clavus. 



External genitalia: Female, last ventral segment much as in alter- 

 natus, short, posterior margin usually slightly sinuate on either side of 

 the slightly produced and faintly notched median portion, lateral margins 

 strongly narrowed posteriorly; pygofers exceeded by the ovipositor by 

 about one-third their length. Male, last ventral segment as in altematus, 

 with long lateral lobes, large median incision with small median lobe, 

 median incision sometimes not as deep as in alternatus; plates, long and 

 slender, equalling the long pygofers; antenna? very short and with very 

 large discs. 



Male internal genitalia: Styles smaller than in snowi, basal part more 

 slender; connective with three basal processes, as in snowi, but upper 

 portion narrow, only half as wide; oedagus Y-shaped, with distinct base 

 and slender upper arm, lower arm simple, without the arrowhead ap- 

 pearance as in snowi; collar around base of anal tube slender and open 

 slightly at tip, forming almost a complete circle. 



Distribution: A species seemingly occurring over the state, 

 as shown by the following map : 



Hosts: Willows. 



