A year-round survey of chironomid midges by light trap collections at Lake Kojima in Okayama Prefecture

Abstract

A year-round survey of chironomid midges was carried out using light traps at Lake Kojima in Okayama Prefecture from July 1985 to December 1986. The final collection site was selected from preliminary collections at 5 spots from July 8 to 9,1985. The annual total of the monthly mean numbers of the collected midges was 41,669 (male 15,795; female 25,874). Twenty-one species of 15 genera were collected, and the major species were Polypedilum arundinetum (14,254), Parachironomus arcuatus (5,234), Microchironomus ishii (4,622), Tanytarsus oyamai (4,057), Chironomus kiiensis (3,004), Tanypus punctipennis (2,490), Pentapedilum tigrinum (2,349), Polypedilum masudai (1,577), Polypedilum nubifer (980), Dicrotendipes niveicaudus (962), Cricotopus sylvestris (936), and Tokunaga-yusurika akamusi (526). Many species of adult midges emerged from June to September. Some species were abundant in the winter, and one species (Limnophyes hudsoni) showed two peaks in its prevalence, in spring and autumn.