TitleThe impacts of urban wetlands on mosquito population dynamics and disease risk at the local scale
NameJohnson, Brian J. (author), Sukhdeo, Michael VK (chair), Robson, Mark G (internal member), Kjer, Karl M (internal member), Winfree, Rachael (internal member), Rutgers University, Graduate School - New Brunswick,
SubjectEcology and Evolution,
West Nile virus—Transmission--New Jersey,
Urban ecology (Sociology),
Mosquitoes as carriers of disease--New Jersey
DescriptionUnderstanding how different urban environments influence the transmission of West Nile virus (WNV) within urban landscapes has been poorly studied. Urban wetlands, which are often the most abundant and beneficial open-space remaining in developed areas, are one such understudied urban environment. Despite the beneficial nature of urban wetlands they have been linked to increases in the occurrence of clinical WNV cases in the northeastern United States. However, the mechanisms behind this association have never been thoroughly investigated. Given this discrepancy, we set out to determine the true impacts urban wetlands have on the transmission of WNV within urban landscapes. Our primary hypothesis is that urban wetlands actually decrease the prevalence of WNV by decreasing the ability of local vector communities to maintain and transmit WNV. To address our hypothesis we surveyed the composition of local vector communities and disease prevalence moving from urban wetlands into adjacent residential/urban environments over a fine spatial scale (<1km). We surveyed a total of six urban wetland sites consisting of three size classes within the state of New Jersey (USA) during the 2009 and 2010 transmission seasons. We found that urban wetlands produced significantly richer (t34=4.77, P<0.001) and more abundant mosquito populations (t34=3.82, P=0.001) compared to urban residential areas. Residential communities also contained higher proportions of container-breeding species (e.g. Culex pipiens and Aedes albopictus). This led to a larger percentage of residential mosquito populations being made up of competent WNV vectors (31.25±5.3%) compared to wetland areas (13.5±2.1%). These increases correlated to higher WNV infection rates in Culex spp. populations residing within residential areas (28.53/1000) compared to wetland areas (16.77/1000). In relation to wetland size, small wetlands produced significantly higher weekly infection rates (24.52/1000) than medium (8.50/1000) or large (6.67/1000) sized wetlands. Additionally, we found that sustained increases in seasonal temperatures increased the community presence of competent vector species (e.g. Culex spp. and Aedes albopictus) and caused dramatic increases in WNV infection rates. Overall, these results confirm our hypothesis that WNV, and its prominent enzootic and bridge vector species, are more strongly associated with urban residential areas than they are with urban wetland areas.
NoteIncludes bibliographical references
Noteby Brian J. Johnson
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.