One year's observation on the ecology of Aedes albopictus Skuse in Foochow.

Aedes albopictus is one of the mosquitoes most often seen in Foochow, but itsecology is not entirely known. Therefore, I have spent a whole year in observing itsecology. The results of my observations are as follows: 1. Aedes albopictus is active in the day time. It is not easy to collect, but theyoften appear in the mosquito net, kitchen, pig sty, drawing-room and among weeds inthe fields. The seasonal distribution of Aedes albopictus covers a period from Marchto December with the highest peak in July, August and September. 2. The daily activity of adult Aedes albopictus show two peaks outdoors, one inthe morning at 5--6 o'clock, and one in the late afternoon at 4--5 o'clock. Indoors,only a single peak, at about 1--5 p.m. 3. The breeding places of the larvae are widely distributed, consisting of small re-ceptacles like vats, cans, urns, etc., with water which is always of a light brownish col-our and with rotten leaves and silt at the bottom. The pH values of the water oftypical breeding places is 6.5--7.6, and the total organic nitrogen is 6--20 p.p.m. 4. The larvae of Aedes albopictus are found in most cases to breed alone, and arerarely found together with those of other insects. 5. The egg of Aedes albopictus hibernate for two months and a half in wintertrom middle of December to end of February. 6. The importance of Aedes albopictus in the transmission of Japanese B encephalitis virus is discussed.