Chironomid (Diptera, Chironomidae) Fauna in a Filtration Plant in Japan

Abstract:
Flights of chironomid midges have caused some problems for residents around water treatment works. The development of physical and biological control strategies against chironomid midges is needed because chemical control is not feasible in slow sand filter beds. In this study seasonal changes in the abundance and species composition of chironomid larvae were investigated in slow sand filter beds in a subtropical region. Through the year, Chironominae was the dominant subfamily (45.3-93.7%), followed by Tanypodinae (6.3-54.7%). No Orthocladiinae were collected. Hanochironomus and Polypedilum were the dominant genera, whereas Tanypodinae, Ablabesmyia was the dominant genus. Polypedilum has been the major pest genus in Japan. The overall factor influencing the abundance of chironomids is water temperature in slow sand filter beds.