Comparative studies of the microbial composition and diversity of container-dwelling mosquitoes

Abstract

The growing problem of mosquito resistance to chemical insecticides has reinforced the urgent need to develop alternative vector control strategies that exploits current advances in mosquito biology including mosquito-microbe interactions. The goal of this research was to develop a better understanding of mosquito microbiota and how their composition and diversity is influenced by host species, life stage, larval habitat type, and larval exposure to commonly used pesticides. Analysis of the microbial communities of larval stages of Aedes japonicus and Aedes triseriatus collected from tree hole and waste tire habitats revealed the bacterial richness to be highest in Aedes japonicus, intermediate in Aedes triseriatus, and in water samples from their larval environment. The microbial communities also clustered by mosquito species, habitat type (used tires vs. tree holes) and study sites. Experimental microcosms were also used to evaluate how exposure of mosquito larvae to sublethal concentrations of atrazine, permethrin, and malathion affects the composition and diversity of mosquito gut microbiota. Bacterial community composition differed according to sample type (larval stage vs. adult stage vs. water sample), but not by pesticide treatment. Bacterial OTU richness was highest in larval samples receiving malathion and permethrin treatments, intermediate in the water and larval samples from the atrazine treatment, and lowest in adult samples irrespective of the treatment. Finally, the microbiota associated with egg rafts and midguts of Cx. pipiens L. and Culex restuans were characterized to gain insights into their community composition and diversity. For each mosquito species, bacterial richness was significantly higher in mosquito egg rafts compared to the midguts. The bacterial community composition differed significantly between egg raft and midgut samples for Cx. restuans, but not for Cx. pipiens L. samples. Overall, these studies have shown that mosquitoes harbor variable microbial communities that are also influenced by the host species, life stage, and the larval habitat. These results provide a basis for future studies aiming to leverage the understanding of mosquito host- microbial symbiont relationships for mosquito vector management.U of I OnlyAuthor requested U of Illinois access only (OA after 2yrs) in Vireo ETD syste