SUBGENUS TRICHAPION — ^KISSINGER 249 



The mucronate tibiae of the male are the chief diagnostic character 

 of the subgenus Trichapion. The middle and hind tibiae of the males 

 of most species are mucronate; a few have all of the tibiae mucronate, 

 while othei-s have only the middle tibia mucronate. In the type 

 species, A. aurichalceum Wagner, and closely allied species the front 

 tibiae bear a flat, polished, striate area on the inner anterior surface. 

 Other male secondary sexual modifications of the legs are swollen 

 femora, spined tarsi, or enlarged tarsal segments. 



The males of a few other species groups of Apion not belonging to 

 the subgenus Trichapion have mucronate tibiae but lack one or more 

 of the other characters that will be listed in the definition. The 

 A. coxale group difl'ers in that the front coxae of the male are tuber- 

 culate. The species of Fall's Group I differ, in addition to many other 

 characters, by the smooth, polished area limited by a raised ridge on 

 the apical ventral surface of the front femur of the male, the nearly 

 simple claws, and the metasternal spicules. Apion redusum Fall 

 and A. acrophilum Fall also differ by their simple claws. The male 

 of A. opacicolle Smith differs by having metasternal spicules similar 

 to Fall's Group I. A. tenuirostnim Smith, A. smithi Wagner, A. 

 impexum Fall, A. metallicum Gerstaecker, and A. troglodytes Manner- 

 heim differ in that the prothorax is widest before the base, the sides 

 not expanded laterally at the base. 



The definition of the subgenus Trichapion Wagner is as follows: 



Legs, coxae, and beak black (evustum, rufipenne, subrufum, 

 ■subtinctum, and vinosum with rufescent legs); body not gibbose in 

 outline, without transverse pattern of scales, not clothed with fine, 

 suberect pubescence; beak curved, apex more slender than base, at 

 most expanded laterally at tip, apical region more finely sculptured 

 than basal region ; anterior portion of the dorsal margin of the antennal 

 scrobe may or may not be oblique; frous generally wider than dorsal 

 top of beak (a few species with frons equal to or narrower than dorsal 

 tip of beak especially of male), not depressed adjacent to eye, with a 

 rather broad median area v/hich may be flat, concave, or with an 

 obvious, deep, longitudinal sulcus; prothorax expanded laterally at 

 base, constricted apicall}^ (perforicolle not constricted), apex obviously 

 narrower than base; middle coxae separated by a complete lamina; 

 first segment of fore tarsus generally longer than wide (with exception 

 of rostrum); third tarsal segment strongly bilobed; claws toothed. 



Although some intermediate forms occur it is convenient to consider 

 the species of Trichapion as falling into two sections, one related to 

 the holarctic Apion simile Kirby and the other to such species as 

 Apion patruele Smith, A. reconditum Gyllenhal, and A. rostrum Say. 

 The first section related to A. simile is chai-acterized by having two 



