Genetic influences on mosquito feeding behavior and the emergence of zoonotic pathogens

Abstract

The feeding behavior of vectors influences the likelihood of<SUP> </SUP>pathogen invasion and the exposure of humans to vector-borne<SUP> </SUP>zoonotic pathogens. We used multilocus microsatellite genetic<SUP> </SUP>typing of an introduced mosquito vector and DNA sequencing of<SUP> </SUP>mosquito blood meals to determine the impact of hybrid ancestry<SUP> </SUP>on feeding behavior and the emergence of West Nile virus (WNV).<SUP> </SUP>The probability of ancestry of <I>Culex pipiens</I> mosquitoes from<SUP> </SUP>two bionomically divergent forms, form molestus and form pipiens,<SUP> </SUP>influenced the probability that they fed on humans but did not<SUP> </SUP>explain a late summer feeding shift from birds to humans. We<SUP> </SUP>used a simple model to show that the occurrence of pure form<SUP> </SUP>molestus mosquitoes would have decreased the likelihood of WNV<SUP> </SUP>invasion (<I>R</I><SUB>0</SUB> in bird populations) 3- to 8-fold, whereas the<SUP> </SUP>occurrence of pure forms pipiens mosquitoes would have halved<SUP> </SUP>human exposure compared with the hybrids that are present. Data<SUP> </SUP>and modeling suggest that feeding preferences may be influenced<SUP> </SUP>by genetic ancestry and contribute to the emergence of vector-borne<SUP> </SUP>pathogens transmitted by introduced species, including malaria,<SUP> </SUP>and dengue, Chikungunya, yellow fever, and West Nile viruses.<SUP> </SUP>