Book Description

West Nile virus (WNV) causes the most reported mosquito-borne disease in the U.S. Vector control is the only realistic option for preventing and mitigating outbreaks of WNV. An integrated mosquito management (IMM) approach to vector control is the best practice for mosquito control organizations (MCOs). For this dissertation, I interrogated IMM practices for WNV mosquito vectors in the suburbs of Chicago, Illinois, USA, an epidemiological 'hotspot' for the disease despite the activity of MCOs. Adulticide application is used to stop outbreaks of WNV, but it remains unclear if adulticide application is effective for population and disease control. To begin to answer outstanding questions about the effects of ultra-low volume (ULV) adulticide applications, I conducted research in collaboration with the Northwest Mosquito Abatement District (NWMAD) in northern Cook County, IL. I evaluated the impacts of weekly truck-mounted ULV adulticide applications for five sequential weeks on Culex pipiens and Cx. restuans population abundance, age structure, WNV infection rates, and insecticide resistance (IR) status. Impacts of Zenivex® E20 application were first evaluated in a non-residential setting in the NWMAD. We observed significant changes in the age structure of the Culex spp. population, but reductions in population abundance and WNV infection were mixed. We then conducted ULV adulticide evaluations with Zenivex® E20 (etofenprox) and Anvil® 10+10 (Sumithrin® + pipronyl butoxide) in large, residential study sites. Study design was improved, revealing significant decreases in both host-seeking and gravid mosquito abundance. A significant reduction in parous females was observed but impacts on WNV infection rate were only detected in one year. Enhanced impacts were observed in Cx. restuans populations compared to Cx. pipiens, potentially due to profound IR in Cx. pipiens populations. I utilized CDC bottle bioassays, caged field trials, and topical applications to assess IR to etofenprox, Sumithrin®, and Anvil ® 10+10, and quantified IR to unsynergized and synergized etofenprox, Sumithrin®, and deltamethrin. I compared each assay, examining the data produced and ease of integration, and provided a decision-making tool for MCOs. Overall, these studies provide the first comprehensive assessment of truck-mounted adulticiding for WNV vector control with direct implications for better protecting public health.