日本脳炎伝搬蚊,特にコガタアカイエカの生態5.コガタアカイエカとシナハマダラカの越冬

The time of awakening from winter diapause in Culex tritaeniorhynchus summorosus and Anopheles sinensis was examined from the data of mosquito catches in winter and early spring from 1965 to 1971 in the Nagasaki area. The results indicated that at least until the end of February most females of G. t. summorosus are still in a diapausing state, i. e., they do not feed on animals even on a warm day, while many of An. sinensis females are in such a physiological state already in January that they can feed on animals if the temperature is high enough for their flight activity. From the observations in the field and the experiments in the laboratory, it was implied that the main overwintering place of C. t. summorosus, and probably An. sinensis too, is the underground small space of stone walls, banks and the likes which are common in the terraced rice field area.コガタアカイエカとシナハマダラカの雌成虫が冬期の休眠から覚醒する時期を,長崎地方で1965-1971年の冬及び早春に採集した蚊の資料を用いて吟味して,次の結果を得た.コガタアカイエカの大多数の雌成虫は少なくとも2月の末までは休眠状態にあり,暖い日であっても吸血に来ることは殆んどない.これに反してシナハマダラカの雌成虫の多くは1月には既に休眠から覚醒していて,気温が飛翔活動に充分なほど高くさえあれば,多数の吸血蚊が観察される.野外及び実験室での観察から,コガタアカイエカが(そしておそらくシナハマダラカも)越冬するのは,階段状の水田が多くある地方の石垣や土手などの中の小さなすき間であるように思われる