Collection Manager Purdue University West Lafayette, Indiana
The epitragine darkling beetles are an endemic New World pimeliine lineage with ~243 described species/subspecies in 37 genera found throughout the Americas, occupying a broad range of habitats, with both widespread and localized taxa. Members of the group are morphologically diverse, with a significant range of body sizes; multiple losses of flight wings; variable cuticular microstructure; production of colorful, waxy cuticular pruinescence; and presence of sexually dimorphic characters. In contrast with the majority of pimeliine tenerionids, which are nocturnal, flightless detritivores, many epitragines are primarily diurnal, flighted beetles, often associated with living plants. The last taxonomic revision of the Epitragini was performed over 50 years ago; however, no attempt was made to reconstruct evolutionary relationships for the tribe or among any component taxa. Further, this revision employed variable external morphological characters, with minimal, fragmentary line drawings of taxa and characters, rendering the descriptions and keys virtually unusable, even by tenebrionid specialists. Subsequent studies have been limited by taxon sampling or geography and no modern revision of the tribe exists. This has resulted in widespread confusion over epitragine taxonomic identities–leading to description of epitragine taxa in related tribes–and, compounded by the absence of evolutionary context, effectively rendered the group inaccessible to both entomologists and other researchers. Using targeted enrichment sequencing and morphological character matrices we analyzed representatives from a majority of epitragine genera and from all related tribes. We present the first phylogeny of the Epitragini and discuss the implications for epitragine taxonomy, tribal composition, and biogeography.