Studies on Adelestini (Hymenoptera, Tenthredinidae), particularly the long-tongued Nipponorhynchus Takeuchi of Japan

Nipponorhynchus brevis Smith & Naito, sp. n., is described from Hokkaido, Japan. It is characterized by shorter mouthparts than those of the other two species of the genus, N. bimaculatus Naito and N. mirabilis Takeuchi. The previously unknown female of N. bimaculatus is described. Larvae of N. bimaculatus and N. mirabilis feed on Chrysosplenium macrostemon var. shiobarense (Saxifragaceae), and notes on the life history are given. Nipponorhynchus is compared with the Nearctic Adelesta Ross, the only other genus of Adelestini. A key to the genera and species of Adelestini is provided.