Geospatial analysis of invasion of the Asian tiger mosquito Aedes albopictus: competition with Aedes japonicus japonicus in its northern limit area in Japan

• Main Authors: Naoko Nihei, Osamu Komagata, Kan-ichiro Mochizuki, Mutsuo Kobayashi
• Format: Article
• Language: English
• Published: PAGEPress Publications 2014-05-01
• Series: Geospatial Health
• Subjects: Aedes albopictus, Aedes japonicus japonicus, competition, normalized difference vegetation index, geographical information system, Japan.
• Online Access: http://www.geospatialhealth.net/index.php/gh/article/view/30

The mosquito <em>Aedes albopictus</em>, indigenous to Southeast Asia and nearby islands, has spread almost worldwide during recent decades. We confirm the invasion of this mosquito, first reported in Yamagata city in northeast Honshu, Japan in 2000. Previously, only <em>Ae. japonicus japonicus</em> had been collected in this place, but 2 years later, the population of <em>Ae. albopictus</em> had increased, so more than 80% of the total number of larval colonies there consisted of this species. In contrast to Yamagata’s new residential area, now infested by <em>Ae. albopictus</em>, the original mosquito remains in the city but its habitats are generally closer to the surrounding mountains, where the normalized difference vegetation index is higher. The factors affecting the distribution of both species in Yamagata city were studied using geographical information systems (GIS) based on data derived from field surveys, aerial photographs, satellite images and digital maps. The range of <em>Aedes</em> mosquito habitats was estimated and visualised on polygon maps and no significant differences were noted when the polygon area was calculated by GIS software in comparison with the satellite images. Although <em>Ae. j. japonicus</em> was expected to be rapidly overrun by <em>Ae. albopictus</em>, this did not happen. Currently, both species coexist; not only in separate sites, but also simultaneously in various water bodies, where larvae from both species have frequently been seen. However, the competitive relationship between these two <em>Aedes</em> species within a warming environment is an issue that should be closely monitored.