DIAPERINI NORTH OF MEXICO — TRIPLEHORN 439 



iridescent reddish, greenish, and golden stripes and blotches on the 

 elytra which appear to be evanescent and should not be relied upon 

 too heavily as an important taxonomic character, as was done by 

 Bates. 



The shape of the pronotum varies from the elongate form with 

 straight sides, prominent apical angles, and deeply emarginate an- 

 terior margin as in A. chrysomelina Lacordaire and A. gibbosa Cham- 

 pion, to the short, more transverse form with rounded sides and 

 apical angles as in A. belti Bates and A. purpureomicans Bates. 



The punctures forming the elytral striae and the relative size and 

 abundance of the punctures of the elytral intervals are constant 

 enough within a species to be taxonomically useful, as are the mi- 

 croreticulations and consequent intensity of the surface lustre of the 

 elytra. 



The form and sculpture of both the prosternal process and the 

 mesosternum likewise may prove constant enough to be of value. 



Unlike most Diaperini, members of this genus apparently are not 

 associated ^\^th fungi. Champion states that the Central American 

 forms are found "upon herbage or by beating the withered, still- 

 attached leaves of fallen trees in new clearings." 



In attempting to establish the identify of the one species of Apsida 

 which has been found north of the Rio Grande, a moderate series of 

 specimens from various sources was accumulated. Through the gener- 

 ous efforts of Mr. J. Balfour-Browne of the British Museum, it was 

 possible to borrow cotypes of all but one of Champion's species and 

 to have specimens compared with those of Bates, 



The most confusing element in understanding the components of 

 this genus is the status of A. purpureomicans, a widely distributed, 

 evidently polymorphic species, which Champion refers to as "one of the 

 most perplexing species of Tenebrionidae I have yet had to deal with." 

 He was able to recognize three distinct varieties, separated entirely 

 on coloration and dorsal surface lustre. To further cloud the issue, 

 there is a smaller species (A. terebrans Champion) which apparently 

 falls well Avithin the range of variation exhibited by A. purpure- 

 omicans and which has been taken in several localities in company 

 with it. The male aedeagus of A. terebrans is deeply cleft apically 

 and quite distinct from any other known species in the genus. In all 

 other species studied, the form of the aedeagus is not at all diagnostic. 

 Until more specimens of this complex can be studied, it seems best 

 to defer any comprehensive review of this genus, since it is impos- 

 sible at this time to add any consequential information beyond what 

 Champion has already contributed. 



