Description of larvae of Japanese Macronychini (Coleoptera: Elmidae: Elminae).

Larvae of 15 species of Macronychini, subfamily Elminae, belonging to the genera Sinonychus Jäch Boukal, Paramacronychus Nomura, Zaitzeviaria Nomura, Zaitzevia Champion, and Urumaelmis Satô were described based on scanning electron microscope (SEM) observation. Larvae of eleven of these species, S. tsujunensis Yoshitomi Nakajima, Zaitzeviaria gotoi (Nomura), Zaitzeviaria brevis (Nomura), Zaitzeviaria kuriharai Kamite, Ogata Satô, Zaitzevia elongata Nomura, Zaitzevia aritai Satô, Zaitzevia yaeyamana Satô, Zaitzevia awana (Kôno), Zaitzevia nitida Nomura, Zaitzevia tsushimana Nomura, and U. uenoi (Nomura) are described for the first time.