Abstract
The fauna and distribution of the blackflies in Fukushima Prefecture were studied based on the collections of larvae and pupae from streams and adults flying around the collectors at 138 sities in summer of 1995. A total of 22,935 blackflies, 20,066 larvae (87.5% in total number), 2,867 pupae (12.5%) and 2 adults (0.01%), were collected at 128 sites. All these blackflies were classified into 18 species of the genus Simulium Latreille and Prosimulium Roubaud. Four species, Simulium (Gomphostilbia) shogakii, S. (Gnus) daisense, S. (Gn.) kisoense and S. (Simulium) nikkoense, were newly recorded from Fukushima Prefecture. The most abundant species was S. (Odagmia) aokii (29.6% in total number), followed by S. (S.) japonicum (23.2%), S. (S.) suzukii (14.1%), S. (Gn.) bidentatum (11.8%) and S. (Nevermannia) uchidai (10.2%). The most widely distributed species was S. (N.) uchidai (88 sites), followed by S. (O.) aokii (83 sites), S. (S.) suzukii (73 sites), S. (S.) japonicum (71 sites) and S. (Gn.) bidentatum (59 sites).
