A mathematical model of Culex population abundance and the impact of vector control interventions in a patchy environment

Recent mosquito-borne disease outbreaks have highlighted vulnerabilities in our mosquito abatement programmes. The possibility of future outbreaks motivates mosquito abatement districts to optimise their control strategies. Spatial dissemination of vector borne disease is caused by the movements of hosts and mosquitoes. It should be noted that the vector activity and the spread of mosquito-borne pathogens are entirely intertwined and there is much of overlap between it. In our current study, we have developed a mathematical model for the dynamics of Culex mosquito populations in a patchy environment, incorporating entomological data, weather-driven factors, and vector control interventions practiced by the Northwest Mosquito Abatement District (NWMAD), Cook County, Illinois, USA. By coupling a temperature-driven multi-patch Ordinary Differential Equation (ODE) model with mosquito abatement strategies utilised by the NWMAD, we have explored how spatial heterogeneity and different mosquito control strategies can potentially affect mosquito abundance. The present study has focused on two mosquito species within the genus Culex : Culex restuans and Culex pipiens. These species were selected because they are among the most abundant Culex mosquitoes in the study region and are recognised as important vectors. We also assess the effectiveness of various vector control strategies, including adulticide and larvicide interventions, under different temporal, spatial configurations. We further have evaluated how mosquito dispersal influences the effectiveness of various control strategies by comparing single and two-patch model outcomes. Our simulations demonstrate that models ignoring spatial connectivity via mosquito dispersal can substantially overestimate the efficacy of different intervention strategies or inaccurately represent the threshold levels required for vector persistence. Through numerical simulations, we have analysed the impact of continuous-pulsatile control measures on population dynamics, providing insight into optimal control strategies for managing Culex populations and mitigating the spread of mosquito-borne diseases while considering of mosquito movements in a weather-driven settings in the Cook County, Chicago, Illinois, USA.