Distributions of larval mosquitoes among bamboo-stump pools which vary in persistence and resource input.

摘要

The authors studied the seasonal occurrence and the distribution patterns of larval mosquitoes in a bamboo (Phyllostachys heterocycla f. pubescens) grove in northern Kyushu, Japan, between April 1995 and April 1996. The number of pools was large from June to August and was small in winter. Deep stumps and semi-closed-type stumps held water more persistently than shallow and open-type stumps, respectively. Open-type stumps trapped more leaves than semi-closed-type stumps and the number of leaves trapped in the open-type stump was positively correlated with the area of the pool. The incidences of Tripteroides bambusa and Aedes albopictus were low early in their breeding season and gradually increased thereafter. In August, the density of T. bambusalarvae per pool was higher in the old (>2 months) pools than in the new pools and was positively correlated with the depth of the stumps. In contrast, the density of A. albopictus did not differ significantly between the new- and old pools and was not significantly correlated with the depth of the stump. The density of A. albopictus was positively correlated with the number of leaves that had been trapped in the stump, whereas the density of T. bambusa was not. In addition to the seasonal fluctuation inhabitat-patch availability, the variations in habitat persistence and resource input among bamboo stumps may facilitate the coexistence of the 2 mosquitoes that were differentially limited by these factors. (The other mosquitoes observed in this study were A. japonicus, Culex kyotoensis, Uranotaenia novobscura and Topomyia yanbarensis).