Ecology of vector mosquitoes of Japanese encephalitis, especially of Culex tritaeniorhynchus. 2. Nocturnal activity and host preference based on all-night-catches by different methods in 1965 and 1966 near Nagasaki City.

All-night-catches of mosquitoes were made four times at human huts, by human-baited-traps, at animal sheds, and by dry-ice-traps, two times in June and once in September, 1965 and once in August, 1966. The hourly distributions of the collected females of Culex tritaeniorhynchus usually had a high post-sunset peak, and occasionally a low peak before or around sunrise. It was also shown that the order of mosquito species in the appearance of the post-sunset peak, early to late, is as follows: Aedes vexans nipponii, and Armigeres subalbatus>Anopheles sinensis, Culex neovishnui, and C. tritaeniorhynchus>C. pipiens pallens. As for the host preference of mosquitoes, it was shown from the percentage compositions of mosquitoes collected by various methods that C. tritaeniorhynchus, An. sinensis, Ae. vexans nipponii, and Ar. subalbatus are zoophilic; C, neovishnui is ornithophilic and zoophilic; and C. pipiens pallens is ornithophilic and anthropophilic.