Modeling the Impact of Migration on Mosquito Population Suppression

Abstract

The field trial of mosquito population suppression in Guangzhou showed that the migration of wild mosquitoes to the target area were resistant to elimination. In this work, we formulate a delay differential equation model to assess the impact of migration on the suppression efficiency, and identify that the migration of wild mosquitoes from surrounding area excludes the possibility of a complete population suppression. Our analysis identifies a lower bound of the suppressed population size, and a lower bound of the suppression rate γ * , which reveals the possible maximum reduction of field mosquitoes in the peak season. For a given suppression rate target γ 0 > γ * , we identify the permitted maximum migration number D(γ 0 ), above which is impossible to reduce the field mosquito density up to (1 − γ 0 ) × 100% in peak season. To reduce more than 95% of Aedes albopictus population during its peak season in Guangzhou within six weeks, the required minimum release number climbs steeply as the migration number increasing near to D(0.05).