Occurrence of Chironomid larvae (Insecta: Chironomidae) in sediments of the Isahaya Bay reservoir from 1998 to 2018

Abstract

Eleven genera of chironomid larvae were identified in sediments of the Isahaya Bay reservoir in western Kyushu, Japan from 1998 to 2018. Since 2005, the dominant genera collected at designated sampling sites were Chironomus and Microchironomus. Larval densities of these two genera were highest in 2011 and 2012. Consequently, adult emergence was also highest in these years. Increased reproduction in these two genera is a result of eutrophication, silty sediment deposition, and algal bloom in the reservoir.