Impact of Environmental Factors on Mosquito Population Abundance and Distribution in King County, Washington

Abstract

Background: Climate, land cover, and other environmental factors have been shown to have a direct impact on the epidemiology of vector-borne diseases. Warming temperatures combined with other effects of climate change and changes in land use have the potential to amplify vector mosquito populations and transmission of arboviruses in King County, Washington. This research aims to provide insight into vector populations that may govern vector-borne disease transmission in King County. Methods: Mosquitoes were trapped at selected areas in King County in summer 2014. Additional mosquito data for King County were gathered and assessed for quality and completeness. Identical sites sampled in 2003 and 2014 were directly compared to determine any changes in mosquito abundance and diversity over an 11-year period. Temperature, precipitation, and land cover data were obtained and investigated for their influence on mosquito abundance using correlative and regression analyses. Results: The correlative analysis found mosquito abundance was significantly positively associated with percent med-high developed land cover, maximum temperature, and minimum temperature variables. Mosquito abundance metrics were found to be negatively correlated with percent forested land cover and average weekly precipitation. Mosquito abundance was significantly higher in 2003 than in 2014, but was unexplained by changes in land cover or climate. Conclusions: Mosquito populations appear to be impacted by the climate and land cover variables studied, but other factors not examined in this study may have greater impacts.