Mosquito microbiota influences mosquito physiology and pathogen development, finally affecting their vectorial capacity. Identifying the factors that affect the composition of mosquito microbial communities in nature is essential for designing effective strategies to control vector-borne pathogens. Here, we used a 16 S rRNA metabarcoding approach to analyse the microbiome of 196 mosquito pools (four females per pool) of three common species: Culex pipiens, Aedes albopictus, and Culiseta longiareolata. Mosquitoes were collected from spring to autumn 2022 in five sampling localities of southern Spain. Mosquito bacterial alpha diversity was higher in Cs. longiareolata compared to Cx. pipiens and Ae. albopictus. In addition, beta diversity and the relative abundance of different bacterial taxa differed among mosquito species. Wolbachia dominated the bacterial community of Cx. pipiens and Ae. albopictus, but were virtually absent in Cs. longiareolata. Furthermore, using Cx. pipiens -the most extensively sampled species here- we further investigated differences in the microbiome composition according to sampling localities, seasons, and avian Plasmodium infection status. Locality and season affected the bacterial alpha and beta diversity, with mosquitoes collected in autumn from the Fuengirola locality showing a higher observed richness. Differences in beta diversity among localities and seasons could be, at least in part, influenced by differences in beta dispersion. The relative abundance of different taxa in Cx. pipiens varied by locality, season, and avian Plasmodium infection status. In sum, both intrinsic and environmental factors influence mosquito microbiome, yet the potential consequences for pathogen transmission should be further addressed. This study provides a comprehensive framework to understand the ecological drivers of wild mosquito microbiome, a key step for predicting vector-pathogen interactions and improving strategies for vector-borne disease control.
Garrigós et al. (Mon,) studied this question.