Bondo, K.J., D. Montecino-Latorre, L. Williams, M. Helwig, K. Duren, M. Hutchinson, W.D. Walter. 2023. Spatial modeling of two mosquito vectors of West Nile virus using integrated nested Laplace approximations. Ecosphere 14(1): e4346. https://doi.org/10.1002/ecs2.4346
The abundance of Culex restuans and Culex pipiens in relation to ecological predictors is poorly understood in regions of the United States where their ranges overlap. It is suspected that these species play different roles in spreading West Nile virus in this region, but few studies have used Bayesian hierarchical spatial models to examine the abundance and predict the distribution of these species. Using mosquito surveillance data collected by the Pennsylvania Department of Environmental Protection from 2002–2016, we used Bayesian hierarchical spatial models to predict mosquito abundance and make predictive risk maps of each of these mosquito vectors throughout Pennsylvania in relation to several ecological and land-use variables that have been found to be important predictors of the abundance of these mosquito species. Developed habitat, temperature, and precipitation were important predictor variables for the abundance of Culex restuans, whereas forested habitat, snow water equivalent and normalized water difference index were important predictor variables for the abundance of Culex pipiens. The spatial distribution of each of these species differed from one another, including a negative relationship between the abundance of Culex restuans and developed habitat, and a negative relationship between the abundance of Culex pipiens and forested habitat. Julian date was modelled as a temporal trend for both species and showed Culex restuans to be more abundant from late April through late June and Culex pipiens to be more abundant from July through September. A seasonal cross-over was observed between these two species, and it occurred in late June. Our results suggest that modelling the spatial abundance of each of these species separately can help gain further insight into understanding the epidemiology of WNV in human and susceptible animal populations in regions where these two mosquito vectors co-exist.