115 - Infection by wMel Wolbachia alters female post-mating behaviors and physiology in the dengue vector mosquito Aedes aegypti

The globally invasive mosquito Aedes aegypti disseminates numerous arboviruses that impact human health. A promising method to control Ae. aegypti is transinfection with the intracellular bacterium Wolbachia, a symbiont that naturally infects ~60% of insects but is normally absent from Ae. aegypti. Transinfection with wMel Wolbachia induces cytoplasmic incompatibility, allowing infected individuals to rapidly invade native populations. Further, Wolbachia infected females are suppressed for their ability to transmit arboviruses. Thus, wMel infected Ae. aegypti are being released in several areas to replace native populations to suppress diseases spread by this species. Wolbachia is reported to have minimal effects on Ae. aegypti fertility, but its influence on other processes related to reproduction is unknown. Female insects undergo several physiological and behavioral changes in response to mating that are required for optimal fertility referred to as female post-mating responses. Female post-mating responses can be modified by environmental factors, such as nutritional status and microbiome composition. To assess how Wolbachia infection influences female Ae. aegypti post-mating responses, we collected Wolbachia-infected Ae. aegypti in Medellín, Colombia, and backcrossed this strain for 7 generations to our laboratory strain. We found that Wolbachia influences female fecundity, fertility, longevity, and re-mating incidence, with some effects observed in a sex-specific manner. Changes in female post-mating responses are not due to defects in sperm transfer by infected males, or sperm storage by infected females. Thus, artificial infection by wMel Wolbachia influence post-mating processes in Ae. aegypti, potentially influencing control programs that utilize Wolbachia-infected individuals.