Description of the instar III larva of Agabus (Acatodes) browni Kamiya, 1934 (Coleoptera: Dytiscidae, Agabinae)

The instar III larva of Agabus (Acatodes) browni Kamiya, 1934 (Coleoptera: Dytiscidae: Agabinae) is described for the first time with emphasis on chaetotaxy. The larva is characterized by a yellow-brown frontoclypeus with a central anterior diamond-shaped dark brown macula, the serrated inner ventral margin of the distal half of the mandible, and the abdominal segment VIII with both short and three pairs of long hair-like setae. The larva is compared to those of A. conspicuus Sharp, 1873, and A. japonicus Sharp, 1873 from Honshu and western Japan. A key to identify the instar III larvae of these species is provided.