340 FAMILY XI. — LYGJEIDJE. 



dd. Costal margin straight only at base if at all; eyes less prominent; 

 osteolar opening without expansion. IV. Nysius, p. 350. 



cc. Basal segment of antenna? not reaching apex of tylus; beak reach- 

 ing or surpassing third ventral; head very long. 



V. Belonochilus, p. 355. 



I. Oncopeltus Stal, 1868, 70. 



Large or medium sized, elongate-oval, impunctate, black and 

 red species having the head short, broad, inserted to eyes, the 

 latter widely separated ; tylus reaching or slightly surpassing 

 middle of first antennal ; ocelli widely separated ; beak reaching 

 first ventral ; antennae slender, longer than head and pronotum, 

 second and fourth joints subequal, third shorter; pronotum 

 subtrapezoidal, narrowed in front, median carina entire ; scu- 

 tellum triangular, apex acute, transversely impressed at base ; 

 elytra covering the abdomen and surpassing its tip ; osteolar 

 canal narrow, curved, margins thickened, rounded at tip. About 

 20 species are known, six from the United States, two of which 

 occur in our territory. 



KEY TO EASTERN SPECIES OF ONCOPELTUS. 



a. Head and side margins of pronotum not pilose, the latter thickened, 

 reflexed, wholly pale; larger, 13 or more mm. 273. fasciatus. 

 aa. Head and side margins of pronotum pilose, the latter not thickened 

 or reflexed and black behind middle; smaller, not over 12 mm. 



274. SEX-MACULATUS. 



273 (432). Oncopeltus fasciatus (Dallas), 1852, 538. 



Elongate-oval. Color black and red; cheeks, side margins of pro- 

 notum, basal and apical thirds of elytra, apex 

 of scutellum, coxae and abdomen in great part, 

 bright red, fading to dull reddish-yellow; re- 

 mainder of body, legs and antenna? shining 

 black; genital plates, some spots near middle of 

 third and fourth ventrals, and front angles of 

 each ventral at sides also black. Pronotum 

 declivent in front, deeply and narrowly im- 

 pressed each side at apical third, the median 

 carina low but evident throughout. Male with 

 genital plate short, convex scarcely protruding 

 beyond sixth ventral. Length, 13 — 18 mm. 

 Fig. 71, X 2. (After Uhler). (Fig. 71). 



Occurs throughout Indiana, May 25 — Oct. 9 ; frequent locally 

 on foliage and pods of the common milkweed, Asclepias syriaca 

 L., adults in May and June, all stages in September and Octo- 

 ber; also on foliage of willow and flowers of goldenrod and 



