An ecological study was made on the larval and imaginal population of Aedes albopictus (Skuse) in a cemetery of Nagoya City, central Japan, from April to November 1968. The present paper reports the larval and imaginal population dynamics from the view point of seasonal change of larval population size, larval age structure, imaginal population size and parous rate. 1) The number of mosquito larvae and pupae sampled from 3 stone basins by a bottom-screened dipper totalled, 2,182,of which 93.6% were Aedes albopictus (Skuse), 5.9% Culex pipiens pallens Coquillett and 0.5% Culex vorax Edwards. The number of adult mosquitoes captured with an aspirator was 532,of which 99.4% were A. albopictus and 0.6% Armigeres subalbatus (Coquillett). 2) Total number of A. albopictus larvae (pupae) in each stone basin was estimated by the application of the removal method (Fig. 1). To make a nearer approach to an understanding of population dynamics in the cemetery as a whole, the data of mosquito counts (x) were treated after being transformed into log (x+1), and the Williams' means were used for interpreting the seasonal changes of larval and imaginal population size. 3) The larval population occurred continuously from middle April to early November, and the population size reached its peaks three times (late April, middle July-early August, late August-middle September), of which the second peak was the largest. The imaginal population occurred from middle May to early November, and the population peaks were observed twice (late June-middle July, early to late September), the first peak being larger (Table 1 and Fig. 2). 4) It was indicated from the consecutive analysis of larval age structure that burst of adult emergence at population level seemed to occur five times (middle April-late May, middle June-early July, early July-late July, late July-late August, early Septmber-middle October) (Fig. 2). This estimation was certified by the mark-release-recapture method using Giemsa or carmine 1/1,000 solutions as marking dye (Fig. 4). 5) Each of imaginal population peaks were accompanied by the prominent increase of parous rate in early July to middle August and late September to middle October. Younger larvae appeared continuously and larval population size increased markedly around the first increase period of parous rate, but neither of such changes was observed in the second increase period (Fig. 2). This seems to indicate that eggs deposited in the second increase period of parous rate go through the winter and that the first larval generation of next year is derived from these overwintered eggs. 6) Discussion was given of the number of eggs hatching during a year in stone basins, remarkable effect given by grave-visitors on the mosquito population, and habitat segregation between A. albopictus and the allied species A. flavopictus.
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Kiyoshi MAKIYA (1974) studied this question.