Description of Aleochara (Xenochara) ichikawai sp. nov., the first confirmed myrmecophilous species of Aleochara Gravenhorst, 1802 from the East Palearctic Region (Coleoptera: Staphylinidae: Aleocharinae)

A new species of the genus Aleochara Gravenhorst, 1802, Aleochara (Xenochara) ichikawai Maruyama, Nozaki & Kamezawa, sp. nov., is described based on specimens collected from nests of the Lasius fuliginosus species group in Japan and the Russian Far East. This species represents the first confirmed case of a myrmecophilous Aleochara in the East Palearctic Region. Although initially misidentified as the European species A. fumata Gravenhorst, 1802, morphological comparison revealed consistent differences that justify its recognition as a distinct, undescribed species.

The new species exhibits a close ecological association with ants but lacks distinct morphological adaptations to myrmecophily. Its discovery contributes to our understanding of the multiple independent origins of ant-association within Aleocharinae. It highlights the Lasius fuliginosus species group as a potential driver of such evolutionary transitions.