Modelling population dynamics based on experimental trials with genetically modified (RIDL) mosquitoes

Abstract

Recently, the RIDL-SIT technology has been field-tested for control of Aedes aegypti. The technique consists of releasing genetically modified mosquitoes carrying a “lethal gene”. In 2016 the World Health Organization (WHO) and the Pan-American Health Organization (PAHO) recommended to their constituent countries to test the new technologies proposed to control Aedes aegypti populations. However, issues concerning effectiveness and ecological impact have not been thoroughly studied so far. In order to study these issues, we develop an ecological model. It presents interdependent dynamics of mosquito populations and food in a homogeneous setting. Mosquito populations are described in a stochastic compartmental setup, in terms of reaction norms depending on the available food in the environment. The development of the model allows us to indicate some critical biological knowledge that is missing and could (should) be produced. Hybridisation levels, release numbers during and after intervention and population recovery time after the intervention as a function of intervention duration and target are calculated under different hypotheses with regard to the fitness of hybrids and compared with two field studies of actual interventions. This minimal model should serve as a basis for detailed models when the necessary information to construct them is produced. For the time being, the model shows that nature will not clean non-lethal introgressed genes.