Effects of environmental changes on vector mosquitoes

点击翻译按钮获取中文摘要

Effects of environmental changes on vector mosquitoes. This project focused on variations in vector mosquitoes possibly affected by environmental changes. Based on field studies conducted in southeast Asia, the project revealed as follows. Among Anopheles minimus group, one of main malaria vectors, we found new sibling species from Ishigaki Island, Japan. A species occupied the similar habitat in lombok island, Indonesia was distinguished as An. flaviorstris. our statistical analysis in 30 years record of malaria vector density and environment in northern Thailand revealed that 3 main malaria vectors, An. minimus group, An. maculatus group and An. dirus group, had not reduced in density in transmission areas (TA). While the densities had clearly reduced in non-transmission areas (NTA). In addition to migration of people, vector density in an area also was indicated as another determinant. Less decrease of the forest in the TA than in the NTA also was confirmed by landuse classification between two periods of 1980s and 1990s using satellite images and aerographs. Effect of deforestation on malaria vectors was suggested. Concerning to dengue vectors, various collections were examined for Aedes aegypti and Ae. albopictus. The attractiveness to human presence was strong in Ae. aegypti. On the other hand Ae. albopictus was rather strongly attracted to vegetation. To totally evaluate an environment to which An. minimus group favors a new approach was challenged. Landscape composition of An. minimus habitats was analyzed using digital photographs taken under fixed protocol. The importance of vegetation cover was confirmed for infestation of the species. This easy method was considered worth while to apply to rough evaluation of vector mosquito habitat.