八丈島で観察されたオオクロバエの生活史

抄録

Field study in Hachijo Island, Tokyo, showed Calliphora nigribarbis Vollenhoven was short-day univoltine insect whose development continued for 6 months (December to May). Adults appeared from November to June in towns (alt. 50m) and from October to July in the montane moss forests of Mt. Hachijo-Fuji (alt. 850m). The number of flies at the upland gradually increased during February to April and then decreased. After the rainy season in June, no adults were trapped throughout summer in both lowlands and uplands. No developing stages were also observed from June to November in both habitats. The first appearance of aged males and females in moss forests in October, suggests that adults aestivate there. After aestivation some females migrate from uplands to lowlands for spawning eggs. The lowland population emerged in spring migrates to uplands for aestivation. This up- and down seasonal migration was confirmed by the release and recapture of marked flies in the field experiment made during the same period. Adults seem to escape from lowlands in order to maintain diapause.