A REVISION OF ROTHIUM MOORE AND LEGNER (COLEOPTERA, STAPHYLINIDAE, ALEOCHARINAE) WITH A DISCUSSION OF ITS PHYLOGENETIC-RELATIONSHIPS

A systematic revision of the aleocharine genus Rothium is presented. R othium is redescribed, and five species are recognized, three of which are described as new (R. pallidus Ahn and Ashe, Type locality-Acapulc o, Mexico, R. ashlocki Ahn and Ashe, Type locality-Academy Bay, Santa Cruz Is., Galapagos, Ecuador and R. evansi Ahn and Ashe, Type locality -Punta Galera, Ecuador). Types and paratypes of the three new species are designated. The late-instar larva of R. sonorensis is redescribed and compared with that of R. giulianii. A key is provided fur separati on of known species of Rothium and illustrations of diagnostic feature s are provided. Rothium is hypothesized to be related tu the tribes My llaenini and Pronomacini rather than the tribe Homalotini based on the very small gland opening on the anterior margin of tergite VII; anter o-lateral angles of mentum prolonged into spinose processes; lacinia o f maxilla elongate, slender, with distinctive distribution of spines i nterdigitating with spinose scales; galea shorter and much more slende r than lacinia, with distinctive small patch of setal on apex, and wit hout setae on mesal edge; base of galea flexible, allowing galeal base to bend at a right angle; cardo of maxilla very elongate; ligula shor t and entire; medial pseudopore field narrow, with few or no pseudopor es; lateral pseudopore fields of prementum without pseudopores; and, l abial palpi elongate. A cladistic analysis of the species of Rothium i s presented.