The effect of dispersal and preferential mating on the genetic control of mosquitoes

Abstract

Mosquito-borne diseases cause significant social and economic damage across much of the globe. New biotechnologies that utilise manipulations of the mosquito genome have been developed to combat disease. The successful implementation of genetic mosquito control technologies may depend upon ecological, evolutionary and environmental factors, as well as the specifications of the chosen technology. Understanding the influence of these external factors will help inform how best to deploy a chosen technology to control vectors of infectious diseases. We use a continuous-time stochastic spatial network model of a mosquito life-cycle coupled to population genetics models to investigate the impact of releasing seven types of genetic control technology: a self-limiting lethal gene, two underdominance threshold gene drives, two homing gene drives and two Wolbachia systems. We apply the mathematical framework to understand control interventions of two archetypes of mosquito species: a short-range dispersing Aedes aegypti and comparatively longer-range dispersing Anopheles gambiae. We show that mosquito dispersal behaviour is an extremely important factor in determining the outcome of a release programme. Assortative mating - where the mating success of genetically modified males is lower than their wild counterparts - can facilitate the spatial containment of gene drives. The rapid evolution of strong mating preference can damage the efficacy of control efforts for all control technologies. We suggest that there cannot be a one-size-fits-all approach to regulation and implementation of vector control; there must be application-specific control plans that take account of understudied ecological, evolutionary and environmental factors.