Histeridae of Socotra (Coleoptera: Histeroidea)

The histerid beetles (Coleoptera: Histeridae) of Socotra Island (Yemen) are reviewed based on the material collected during the Czech expeditions undertaken between 2000 and 2012. A total of 20 species are recorded, three of which are described herein: Pachycraerus socotrensis sp. nov., Liopygus occidentalis sp. nov., and Teretrius (Neoteretrius) dispar sp. nov. Hypocaccus virescens Therond, 1963 is transferred from the subgenus Baeckmanniolus Reichardt, 1926 to Hypocaccus s. str. Thomson, 1867 based on external morphology. Most taxa, albeit determined only up to their (sub)generic rank, are recorded from Socotra for the first time. Due to poor understanding of their taxonomy, or lack of determination keys to the following (sub)genera: Tribalus Erichson, 1834, Plegaderus (Plegaderus) Erichson, 1834, Acritus (Acritus) LeConte, 1853, and Teretrius (Teretrius) Erichson, 1834, their representatives from Socotra are left without identification pending revisions. The Socotran histerid fauna has been found to consist mainly of widely distributed African, Arabian/Near Eastern taxa, as well as local endemics. The occurrence of the (predominantly Holarctic) genus Plegaderus and the exclusively southeast Asian genus Liopygus Lewis, 1891 in Socotra is highly interesting.