364 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 117 



Key to North American Genera of Diaperini 



1. Genae entering anterior margins of eyes (only slightly in Scaphidema) ; eyes 



moderate to large in size and reniform in shape; elytra almost always 



punctate striate 2 



Genae extending to anterior margins of eyes but not entering them; eyes 

 very small and rounded; elytra confusedly punctured. 



Pentaphyllus Dejean (p. 445) 



2. Mesosternum anteriorly notched between middle coxae for reception of 



posternal process in repose 3 



Mesosternum prolonged cephalad as a rounded lobe which overlaps and 

 conceals prosternal process in repose (pi. 3, fig. 14). 



Liodema Horn (p. 435) 



3. Anterior projection of basal abdominal sternite broadly truncate between 



hindcoxae; all coxae widely separated. 



Scaphidema Redtenbacher (p. 432) 



Anterior projection of basal abdominal sternite acute between hindcoxae; 



all coxae narrowly separated 4 



4. Basal segment of hindtarsus short, subequal in length to second segment. 5 

 Basal segment of hindtarsus longer, subequal to or longer than second and 



third segments combined 6 



5. Body broadly oval, strongly convex dorsally, almost hemispherical; elytra 



boldly patterned with red or orange and black (except coccinea Laporte, 

 from South America), shining; never with frontal horns in either sex. 



Diaperis Mtiller (p. 365) 



Body elongate, cylindrical; elytra always unicoloi-ous; males (at least in 



North American species) with conspicuous frontal horns between eyes; 



females with tubercles instead of horns or entirely lacking cephalic 



armature Neomida Latreille (in part) (p. 374) 



6. Epipleura abruptly abbreviated at or near last visible abdominal suture . 7 

 Epipleura attaining or almost attaining elytral apices, always distinct well 



beyond last visible abdominal suture 8 



7. Antenna with terminal 5 segments abruptly expanded to form a loose club; 



body broadly oval, strongly convex dorsally, nearly hemispherical; neither 



sex with frontal horns Apsida Lacordaire (p. 438) 



Antenna with at least 7 segments expanded to form club; body elongate, 

 cylindrical; males (at least in North American species) with conspicuous 

 frontal horns, females with tubercles instead of horns or entirely lacking 

 cephalic armature Neomida Latreille (in part) (p. 374) 



8. Entire dorsal surface with conspicuous vestiture of light colored, short, 



recumbent setae arising from punctures 9 



Dorsal surface without vestiture 10 



9. Elytra bicolored; head of male with clypeus grotesquely swollen and with 



2 longitudinal, parallel, carinate ridges on frons near epistomal margin 

 (pi. 6, fig. 57) ; head of female simple . Alphitophagus Stephens (p. 441) 

 Elytra unicolorous; head of male with conspicuous frontal horns; head of 

 female horned, tuberculate or unarmed. 



Neomida Latreille (in part) (p. 374) 



10. Anterior margin of pronotum truncate or slightly rounded; antenna short, 



not attaining base of pronotum, outer 7 segments strongly transverse 



forming a compact club Palembus Casey (p. 387) 



