Abstract
Larval conditions of holometabolous insects can have a substantial impact on adult life history traits including mortality, fecundity, and pathogen infection. For example, in Anopheles stephensi, overcrowded larval environments has been shown to reduce adult size, decrease fecundity, and increase Plasmodium berghei development. Presently, we are interested in the carryover effects of larval exposure to abscisic acid (ABA) on A. stephensi. ABA was first described as a plant hormone, but is now known for its effects as a stress hormone across animal taxa. We have previously shown ABA transiently alters adult mosquito metabolism through phosphorylation of metabolic mediators in the midgut following a supplemented blood meal. In this study, A. stephensi larvae were exposed to ABA for the entirety of their development and adult females derived from treated or control larvae were evaluated for fecundity, nutrient stores, and life span. Treatment of ABA in larval water significantly increased their development speed, while increasing pupal mortality. We also found that ABA supplementation during larval development has significant carryover effects on adult females, reducing their reproductive output and shortening their lifespan through reduced nutrient acquisition of larvae. Adult mosquitoes exposed to ABA during larval development also have reduced expression of insulin-like peptides (ilps), thus supporting our findings of reduced fecundity and nutrient storage. These findings suggest larval exposure to ABA has the capacity to affect numerous adult life history traits related to vector biology, which could benefit areas with endemic mosquito-borne diseases.