A new record of Potamia littoralis Robineau-Desvoidy (Diptera : Muscidae) bred from birds' nests in Japan

Abstract

The flies of the genus Potamia Robineau-Desvoidy are distributed in the Holarctic Region. Two species, P. littoralis (R.-D.) and P. setifemur (Stein), are known to occur in the Palaearctic Region (Soos, 1986). In Japan, however, there has been no record of this genus until now. During a survey on dipterous flies inhabiting birds' nests, we collected a muscid species bred from some nests. This species was identified to be Potamia littoralis Robineau-Desvoidy, 1830. In the present paper, we newly record this species from Japan and redescribe it on the basis of Japanese specimens.