A review of the species groups of the Western Hemisphere Onthophagus Latreille (Coleoptera: Scarabaeidae: Scarabaeinae) using COI barcoding and gene trees

Species groups of Western Hemispheric Onthophagus Latreille (Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini) are suggested using COI barcoding and gene trees and supported by congruence with external morphology, behavior, ecology, and biogeographic evidence. New species groups, complexes, and taxonomic statuses are offered, and other preexisting proposals are confirmed. No barcoding gap w as found between the intragroup and intergroup genetic distance blocks, but the average intragroup (8.38%) and intergroup (13.88%) Kimura-two-parameter distances are statistically different.

The following seven preexisting species groups were supported by the congruence between the mtDNA barcode analysis and other independent evidence: O. chevrolati, O. clypeatus, O. dicranius, O. gazellinus, O. hircus, O. landolti, and O. mexicanus. Eight new species groups are suggested: O. crinitus, O. curvicornis, O. eulophus, O. hecate, O. hoepfneri, O. marginatus, O. nasutus, and O. velutinus. Possible behavioral/ecological adaptations of morphological characters are also discussed.

New biogeographic and evolutionary hypotheses are also advanced. An identification key for species groups is presented.