ncts

Abstract: Wolbachia is a naturally occurring bacterium that can infect Aedes mosquitoes and reduce their ability to transmit mosquito-borne diseases, including dengue fever, Zika, and chikungunya. Field release programs have been conducted worldwide for population modification as well as population suppression, yet predicting whether a release will achieve effective disease control remains a central challenge. We begin with an ODE model tracking the full mosquito life cycle and Wolbachia vertical transmission. We derive an explicit threshold condition for successful population replacement and characterize the backward bifurcation structure, which leads to the release threshold condition. We then extend this framework to a reaction-diffusion PDE model incorporating spatial heterogeneity from mosquito dispersal in a two-dimensional domain. We quantify how the spatial invasion threshold and wave velocity depend on diffusion and life-history parameters, compare spatially homogeneous and heterogeneous settings, and examine release scenarios to inform efficient field interventions. Time permitting, we briefly discuss ongoing work on Wolbachia-based population suppression strategies, where density-dependent regulation of the population can impact the success of Wolbachia control, including unintended increases in mosquito population size.