Abstract
A fauna and distribution of blackflies (Simuliidae : Diptera) in Chiba Prefecture were investigated by collection of larvae and pupae. A total of 2,855 larvae and 652 pupae was collected from 54 sites. One genus, including eleven species were found, of which Shimulium subcostatum, S. mie, S. konoi, S. takahasii, S. japonicum and S. suzukii were newly recorded. The predominant species was S. bidentatum, followed by S. japonicum, S. uchidai, S. aokii, S. takahasii and S. nikkoense.
