Observations on the seasonal prevalence of chironomid midges and mosquitoes by light traps set in a rice paddy area in Tokushima

Abstract

Collections of chironomid midges and mosquitoes with light traps were carried out in a rice paddy area in the suburbs of Tokushima City, western Japan, in order to elucidate the species and their seasonal prevalence. Five light traps were operated once every week as a rule from April to the end of October 1984. As the results, a total of 32,823 males and 41,691 females of the chironomids as well as 1,822 males and 2,380 females of hte mosquitoes were collected by two light traps. The chironomids were classified into some 40 species, among which the more abundant were Tanytarsus oyamai (34,294 in total), Cricotopus trifasciatus (12,482), Polypedilum kyotoense (11,256), Chironomus circumdatus (5,115), Chironomus kiiensis (4,953), Polypedilum nubifer (2,481) and Chironomus yoshimatsui (2,255). In general, the midges were most abundant from middle of June to the beginning of July, but differences were seen in the seasonal distribution among the species groups. The mosquitoes collected were Culex tritaeniorhynchus (2,274), Culex pipiens (1,501) and Anopheles sinensis (457). The first and the third species were found during the shorter period in midsummer than the second species, which appeared earlier in May and were found to the end of October.