New Targets for Reproductive Control of Mosquito Vectors Project summary/abstract In this project, we will investigate the actions of specific male seminal fluid molecules in promoting fertility and fitness of the major disease vector of dengue, Zika yellow fever and chikungunya viruses, Aedes aegypti. We will also define and analyze Aedes male and female molecules that associate with and support sperm. Despite the crippling impact of arbovirus infections, conventional mosquito control using insecticides can be operationally difficult and is often ineffective. Strategies to replace or reduce populations through modified male-releases show promise, but their success requires a deep understanding of mosquito reproductive biology. Ae. aegypti males transfer molecules in their seminal fluid to females during mating that induce female behavioral and physiological changes, including stimulation of egg development and oviposition, increased survival, and reluctance to re-mate with subsequent males. Despite the potential of these molecules as vector-control targets, the molecular identity and actions of these molecules are as yet unknown. During the current funding period, we utilized the latest tools to gain novel insights into key aspects of male mating success, sperm biology and female reproductive fitness, including identifying a limited subset of seminal fluid proteins (Sfps) that induce post-mating changes in females, and small-molecules such as juvenile hormone (JHIII) in seminal fluid. We propose two specific aims to (1) identify the role of individual male seminal molecules on female remating, fecundity, fertility, oviposition, lifetime reproductive success and survival and (2) to evaluate the role of male- and female-derived molecules on sperm storage, function, and survival. Our long-term goal is to design and deploy vector control strategies that target these key components of mosquito life history to reduce the tremendous global burden of mosquito-borne diseases.