Phylogeny and evolution of large body size in the rove beetle genus Phlaeopterus Motschulsky, 1853 (Coleoptera: Staphylinidae: Omaliinae: Anthophagini)

Abstract The omaliine rove beetle genus Phlaeopterus Motschulsky, 1853 contains 22 species. is distributed across northwestern North America and eastern Asia. These beetles occur primarily along the edges of alpine snowfields streams, habitats that are particularly sensitive to impacts climate change. Two species have not been collected since 1979 1984, one which, bakerensis Mullen Campbell, 2018, a contender for largest-bodied among over 1,600 subfamily Omaliinae. Here, we present first phylogeny genus, using Bayesian maximum likelihood analyses based on DNA sequences from mitochondrial gene COI morphological data. We tested previous taxonomic hypotheses most were rejected by all three analyses. castaneus Casey, 1893 non-monophyletic may hybridized with P. loganensis Hatch, 1957. found support monophyly . Our suggest common ancestor had small-bodied adults (maximum body size under 5 mm) ocelli. Within this radiation species, ocelli lost once there two separate evolutionary transitions large-bodied adults. Although snowfield-associated only 25% are, did find statistical relationship between large use snowfield habitats. findings represent modern phylogenetic reconstruction species-level relationships within Omaliinae both molecular