Role of the repartition of wetland breeding sites on the spatial distribution of <it>Anopheles </it>and <it>Culex</it>, human disease vectors in Southern France

• Main Authors: Fontenille Didier, Ezanno Pauline, Balenghien Thomas, Cailly Priscilla, Toty Céline, Tran Annelise
• Format: Article
• Language: English
• Published: BMC 2011-05-01
• Series: Parasites & Vectors
• Online Access: http://www.parasitesandvectors.com/content/4/1/65

<p>Abstract</p> <p>Background</p> <p>In this study, carried out in the Camargue region (France), we combined entomological data with geomatic and modelling tools to assess whether the location of breeding sites may explain the spatial distribution of adult mosquitoes. The species studied are important and competent disease vectors in Europe: <it>Culex modestus </it>Ficalbi and <it>Cx. pipiens </it>Linnaeus (West Nile virus), <it>Anopheles atroparvus </it>Van Thiel, a former <it>Plasmodium </it>vector, and <it>An. melanoon </it>Hackett, competent to transmit <it>Plasmodium</it>.</p> <p>Using a logistic regression model, we first evaluated which land cover variables determined the presence of <it>Culex </it>and <it>Anopheles </it>larva. The resulting probability map of larval presence then was used to project the average probability of finding adults in a buffer area. This was compared to the actual number of adults collected, providing a quantitative assessment of adult dispersal ability for each species.</p> <p>Results</p> <p>The distribution of <it>Cx. modestus </it>and <it>An. melanoon </it>is mainly driven by the repartition of irrigated farm fields and reed beds, their specific breeding habitats. The presence of breeding sites explained the distribution of adults of both species. The buffer size, reflecting the adult dispersal ability, was 700 m for <it>Cx. modestus </it>and 1000 m for <it>An. melanoon</it>. The comparatively stronger correlation observed for <it>Cx. modestus </it>suggested that other factors may affect the distribution of adult <it>An. melanoon</it>. We did not find any association between <it>Cx. pipiens </it>larval presence and the biotope due to the species' ubiquist character.</p> <p>Conclusion</p> <p>By applying the same method to different species, we highlighted different strengths of association between land cover (irrigated farm fields and reed beds), larval presence and adult population distribution.</p> <p>This paper demonstrates the power of geomatic tools to quantify the spatial organization of mosquito populations, and allows a better understanding of links between landcover, breeding habitats, presence of immature mosquito populations and adult distributions for different species.</p>