SUBFAMILY III. — ORTHOTYLIN^. 859 



Group B. — Orthotylus. 



Usually elongate, slender, subparallel species having the 

 base of vertex sharply carinate and with a bi-impressed con- 

 cavity between the base of eyes ; pronotum about as long as 

 broad; legs long and slender. Color usually pale brownish- 

 yellow or reddish-yellow, with more or less fuscous or blackish, 

 the elytra typically having the clavus and apical half of corium 

 in part fuscous or black. To this group belong 13 of our east- 

 ern species of the genus. 



KEY TO EASTERN SPECIES OF GROUP B, ORTHOTYLUS. 



a. Form oblong-ovate; color a nearly uniform whitish- or pale brown- 

 ish-yellow; elytra translucent; head and calli yellowish; host plant, 

 marsh cudweed, Gnaphalium uliginosum L. 937. catulus. 



aa. Form more elongate, sides subparallel; elytra with fuscous areas, or 

 at times nearly black. 

 6. Color pale testaceous, elytra translucent with dark markings faint, 

 almost wanting in female; median line of head and scutellum, 

 side margins of pronotum and sides of under surface black; host 

 plant American aspen, Populus tremuloides Michx. 



938. CANDIDATUS. 



66. Ground color sometimes pale greenish- or yellowish, but dark 

 markings of elytra always distinct. 

 c. Upper surface brownish-black, the elytra with only the embolium, 

 narrow base of corium and nerves of commissure pale; median 

 line or spot of pronotum and sometimes of scutellum pale; 

 length, 6.8 — 7 mm.; host plant, yellow birch, Betula lutea 

 Michx. 939. necopinus. 



cc. Elytra in female with more than embolium and slender base of 

 corium pale; in male sometimes nearly wholly black; length 

 usually less than 6 mm. 

 d. Pronotum with side margins black, disk broadly pale or reddish- 

 yellow, sometimes with only the median line pale. 

 e. Disk of pronotum and sometimes the elytra in part, fulvous or 

 reddish-yellow. 

 /. Elytra black, the female with a broad pale stripe extending the 

 full length of corium and connecting with the pale cuneus ; 

 legs fulvous, apical half of hind femora blackish; length, 5.4 

 mm.; host plant, balm of gilead, Populus candicans Ait. 



940. KNIGHTI. 



//. Elytra chiefly fulvous or salmon colored, blackish each side of 



commissure and on embolium; length, 4.7 mm.; host plant, 



black locust, Robinia pseudacacia L. 941. submarginatus, 



ee. Disk of pronotum with pale or greenish. 



g. Pronotal disk broadly pale; scutellum black; membrane and 

 apical half of cuneus dark fuscous; clavus and a broad trans- 

 verse band across apex of corium, fuscous-black; length, 

 5.5 — 6 mm. 942. cruciatus. 



