Investigating spatiotemporal population dynamics of West Nile virus mosquito vectors at a broad geographic scale

Multiple mosquito species are competent vectors for West Nile Virus (WNV), with varying distributions across different habitats and regions, adding complexity to understanding the spatiotemporal dynamics of transmission. However, observations of spatially synchronous patterns in WNV spillover from local to broad geographic regions suggests multiscale spatiotemporal factors contribute to local scale transmission outcomes. Here we investigated whether similarity exists in temporal population dynamics (i.e. spatial synchrony) of the primary vector species Culex tarsalis across 14 National Ecological Observatory Network stations in the Continental United States, and we investigated phenological onset of Culex pipiens mosquitoes at a more local scale across landscapes in Chicago between 2000-2020. Mosquitoes were collected using C02 baited CDC light traps and counts were standardized for trapping effort. We used wavelet phasor mean fields to quantify whether significant spatiotemporal phasing occurred at specific time scales for Cx. tarsalis abundances, and we performed wavelet coherence analyses on phenological onset values of Cx. pipiens in Chicago. Preliminary results suggested spatial synchrony at short time scales across all 14 NEON sites in 2018, indicating that Cx. tarsalis populations exhibited similar dynamics across multiple ecoregions. In Chicago, landscape had a significant effect on phenological onset for Cx. pipiens and mosquitoes collected in medium developed landscapes lagged onset in lower developed landscapes, but this lag did not occur every year. Investigating the timing of population dynamics of vector species across multiple scales has the potential to provide a predictive basis for spillover events, which can be used for effective mitigation strategies.