Horizontal and elevational distribution of Culex pipiens complex mosquitoes compared with Aedes albopictus in an inland mountain area, Nagano Prefecture, Japan

Nagano Prefecture, an inland mountain area of Japan, extends widely north and south, with elevation that varies greatly by location. Mosquitoes transmitting infectious disease have a diversity of habitats in Nagano, and many species can be expected there. However, there have been few reports about mosquito fauna in this region; in particular, little information is available on mosquitoes such as Culex (Culex) pipiens complex and Aedes (Stegomyia) albopictus. In this study, we investigated the mosquito fauna in 17 areas to clarify their horizontal and elevational distribution patterns between July and September from 2012 to 2014. We focused especially on Cx. pipiens complex compared with Ae. albopictus. A total of 1,117 mosquitoes were collected, and identi ed as belonging to 17 species. e most abundant species was Cx. pipiens complex, followed by Ae. albopictus. Both species were mainly collected in the southern and eastern parts of Nagano Prefecture, excluding highland areas. Ae. albopictus was collected at a maximum elevation of 789 m while Cx. pipiens complex was collected at a maximum elevation of 996 m. at means the habitat of Cx. pipiens complex was more widely distributed than that of Ae. albopictus. e annual mean air temperature of the site at 789 m was estimated to be 10.2°C and that of the site at 996 m was estimated to be 8.5°C. ere was a di erence of 207 m in elevational distribution between the two species, with a di erence in annual mean air temperature of 1.7°C.