The subgenus Pentapedilum Kieffer (Diptera: Chironomidae) in the Yaeyama Islands, the Ryukyus, Japan

As a result of a multi-year survey, we recognize three Pentapedilum species, including a new species, from Iriomote Is-land, Japan. Polypedilum (Pentapedilum) acristylum sp. nov. is described as adult male, and compared with the closest P. (Pe.) nodosum Johannsen, 1932. Pentapedilum iriodeeum Sasa et Suzuki, 2000 is treated as a junior synonym of P. (Tripodura) tananense Sasa et Hasegawa, 1988. Since the subgenus Pentapedilum Kieffer, 1913 defined solely by the presence of macrotrichia on the wing membrane may not be enough to support monophyly, we suggest the possibility that species with wing macrotrichia restricted to the extreme tips of the membrane, like Polypedilum (Pentapedilum) tigrinum (Hashimoto, 1983), may be placed in the subgenus Polypedilum Kieffer, 1912.