Abstract
The investigation on the mosquito populations collected with the pig baited trap and the dry ice baited trap was carried out on the paddy field area of Natori City, Miyagi Prefecture during the three years, 1965-1967. The results obtained are summarized as follows : 1. Of all the trapped specimens, more than 99 percent belonged to the unengorged females of the following five species-Culex tritaenior-hynchus summorosus, Anopheles sinensis, Culex pipiens pallens, Aedes vexans nipponii and Armigeres subalbatus. 2. The species compositions show remarkable difference between the pig baited trap and the dry ice baited trap in relative abundance of Culex tritaeniorhynchus summorosus, Anopheles sinensis and Culex pipiens pallens. 3. After the peak of seasonal abundance the numbers of mosquitoes decrease abruptly in all the mosquito populations when sampled by the dry ice baited trap. This might be caused by the difference of the age structure of the mosquito population attracted by different kinds of baits. 4. The seasonal succession of the mosquito population structure is almost identical between both traps. However, Anopheles sinensis as dominant species in the population appears in the pig baited trap later than in the other. 5. Moreover, annually the seasonal prevalence of each species and the seasonal succession of the mosquito population structure changed considerably in the both traps.
