An integrative taxonomy of the genus Stephostethus in Taiwan, with descriptions of four new species (Coleoptera, Latridiidae)

Latridiidae is a small family within Coleoptera, with over 800 species and 31 genera worldwide. The family is mainly fungivorous, and can be found in leaf litter, on living vegetation, dead dry branches, rotten wood and tree bark. Some species can be found in the indoor environment and are associated with stored products. The genus Stephostethus in Taiwan was previously known to contain three species, S. chinensis (Reitter), S. taiwanus Ho, Rücker & Chan and S. yuanfengensis Ho, Rücker & Chan. Stephostethus chinensis (Reitter) is from the Palaearctic, and other species are endemic to Taiwan. In this study, we revise the genus based on comparative anatomy and molecular species delimitation methods. As a result, we describe four new species: S. tricarinatus sp. nov., S. cornutus sp. nov., S. truncatus sp. nov. and S. longidens sp. nov. All the new species can be found in the mid-altitude area in Central Taiwan, and S. longidens sp. nov. can also be found in Southern Taiwan. The descriptions, habitus and male terminalia of the four new species are provided. The COX1 and 28S sequences of S. chinensis (Reitter), S. taiwanus Ho, Rücker & Chan, S. yuanfengensis Ho, Rücker & Chan, S. cornutus sp. nov. and S. truncatus sp. nov. are provided and analysed. We conduct maximum likelihood and Bayesian inference analyses, and all species are recovered as a monophyletic group. The relationships of all species of Stephostethus in Taiwan with adjacent areas based on morphological characters are also discussed. ZooBank: urn:lsid:zoobank.org:pub:970F59EE-42D0-4D86-8523-336F7DD3B3BE.