Molecular phylogeny of Trictenotomidae (Coleoptera: Tenebrionoidea): insights into species validation and biogeography of genus Autocrates

Trictenotomidae, one of the most charismatic and enigmatic groups of beetles, known for their large size and distinctive mandibles, is widely distributed throughout tropical and subtropical Asia. New species are continually being discovered, and the known range of the group has been expanded considerably by the discovery of Autocrates maqueti Drumont in the Korean Peninsula, similar to 2,000 km from its previously known distribution in the Chinese mainland highlands. A comprehensively sampled multigene phylogenetic tree of Trictenotomidae, including all six species of Autocrates and five species of Trictenotoma, was reconstructed using multigene data. Using the resulting phylogeny, we performed divergence time estimation, biogeographical assessments, and molecular species delimitation. All six known species of the genus Autocrates were found to be valid in all four molecular species delimitation scenarios, indicating the need for further taxonomic research on these poorly understood taxa. The A. maqueti population in South Korea forms a genetically distinct clade in all genetic analyses, suggesting that it is a natural distribution rather than a result of anthropogenically driven spread. The Korean A. maqueti population is likely to have been isolated since similar to 1.8 Mya, when the Yellow Sea was still a landmass, highlighting the need for targeted conservation measures in South Korea.