A review of the microbiome's role in resistance evolution and life-history trait variation in mosquitoes.

Vector control programs have historically relied on chemical insecticides including organochlorines, organophosphates, carbamates, and pyrethroids but the rapid escalation of insecticide resistance in mosquito populations now threatens the sustainability of these interventions. While genetic and biochemical resistance mechanisms are well characterized, emerging evidence implicates the mosquito microbiome as an additional, underexplored factor influencing resistance. Several microbial taxa (Bacillus cereus, Enterobacter cloacae, Pseudomonas spp., Wolbachia) have been associated with detoxification pathways, yet causal links between these microbiota and specific resistance phenotypes remain weakly defined. Furthermore, the extent to which microbiome shifts modulate mosquito life-history traits such as survival, fecundity, and development time under sustained insecticide selection remains largely unknown. These traits are key determinants of vectorial capacity, and microbiome-mediated changes could alter disease transmission dynamics in ways not currently accounted for in control strategies. This review critically synthesizes evidence from 2005-2024, drawing on peer-reviewed studies, systematic reviews, and experimental work from NCBI, PubMed, ScienceDirect, and Google Scholar. We evaluate the interplay between insecticide-driven selection, microbiome composition, and mosquito biology, highlighting mechanistic uncertainties, methodological limitations, and gaps in longitudinal validation. The analysis underscores the urgent need for integrative research combining microbiome manipulation, functional genomics, and ecological monitoring to move from correlation to causation. By clarifying the microbiome-resistance nexus, this work aims to inform more sustainable, evidence-based strategies for long-term vector control.