The genera Mouffetina Frey and Trichosia Winnertz (Diptera, Sciaridae) in Japan with a key for the Japanese species and an updated world checklist

Taxonomy of the genera Mouffetina Frey and Trichosia Winnertz of black fungus gnats in Japan is studied. Seven new species, M. duopalpus sp. nov. , T. stylofornix sp. nov. , T. fumoranea sp. nov. , T. basiconstricta sp. nov. , T. paraborealis sp. nov. , T. comprimera sp. nov. , and T. montaclaria sp. nov. are described, and six species T. scotica , T. conglobata , T. acrotricha , T. hypertricha , T. lengersdorfi and T. edwardsi are newly recorded from Japan. This study records the species of Mouffetina from Japan for the first time, and increases the number of known Japanese Trichosia from only one species to thirteen species. Intraspecific morphological variability of the widely distributed species is discussed. The larva of T. conglobata is described in detail, and its morphology compared with larvae of other genera of black fungus gnats. Updated world checklist is attached to overview the diversity of the members of these genera.