Chironomid midges collected in Okayama Prefecture during the summer in 1985 and 1986

Adult chironomid midges were collected using light traps at 9 stations in Okayama Prefecture. The light traps were set for an entire night once a month from May to September in 1985 and 1986. A total of 34,313(1985) and 73,667(1986) chironomid midges were collected. Among them, the dominant species were Chironomus yoshimatsui(7.3%), C. kiiensis(18.3%) and Tanytarsus oyamai(14.1%). They emerged mostly in July and August. Sixty par cent of the weight of all air-dried midges was recorded in July.