Contrasted impacts of commercial diets and rearing water on Aedes aegypti fitness and microbiota

Mosquito rearing optimization in laboratory conditions is crucial for both vector research and control. Although the addition of nutrients is important for Aedes aegypti development from immature stages to adult mosquitoes, little is known about the nutrient composition of commercial diets used for mosquito rearing and their influence on Ae. aegypti life traits. Here, we evaluated the influence of four commercial diets commonly used to rear Ae. aegypti in the laboratory on its fitness, lifespan and microbiota. We also compared the effect of these diets on this mosquito when combined with two different rearing waters (laboratory versus field-collected waters). Our investigations demonstrated that higher levels of protein and lipid in commercial diets promote better Ae. aegypti development, lifespan and size in both water. Metagenomic analysis revealed specific modulations of adult microbiota composition according to both diet and rearing water. Chryseobacterium dominated the microbiota of female mosquitoes reared in laboratory water, except for yeast condition, where a more diverse microbiota was observed. When reared in larval site waters, the microbiota diversity was overall higher despite diet addition, except for fish food, which promoted Sphingobacterium dominance. Given the pivotal influence of diet addition during the larval stage on Ae. aegypti microbiota and life traits, rearing conditions should be carefully chosen according to the goals of the research (i.e. vectorial capacity estimations) or vector control intervention.