The North American asidines (Tenebrionidae: Pimeliinae: Asidini) are a large diverse group of flightless desert dwelling beetles. With over three hundred species and subspecies in 26 genera they make up approximately 20% of the total North American tenebrionid fauna. Currently generic boundaries within the tribe are poorly defined and a preliminary phylogenetic analysis shows that many of the genera are not monophyletic and may not warrant generic status.