Warmer temperature and aging interactively reduce mosquito blood feeding and reproduction

Mosquitoes must take a bloodmeal in order to reproduce. But like most organisms, mosquitoes undergo senescence, which is a deterioration in body condition and physiological function with aging, increasing their likelihood of dying. Because it takes time to produce eggs, the age when a mosquito ingests a blood meal can determine whether reproduction is feasible. Moreover, mosquitoes cannot regulate their body temperature, so rising global temperatures are increasing their body temperature and altering the rate of their physiological processes. Given that mosquito metabolism is faster when the temperature is warmer, we hypothesized that warmer temperature accelerates senescence, uncoupling physiological age from chronological age. Here, we investigated how warmer temperature and aging, independently and interactively, shape blood feeding, reproduction, and subsequent survival in the African malaria mosquito, Anopheles gambiae. We found that warmer temperature and aging individually reduce the proportion of mosquitoes that take a bloodmeal, decrease bloodmeal size, and decrease oviposition, fecundity, and survival after a bloodmeal. Importantly, at warmer temperatures, we found that blood feeding and reproductive outcomes decline earlier in the mosquito’s life, demonstrating that warmer temperature accelerates senescence in mosquitoes. The interactive effects of warmer temperature and aging may alter mosquito population ecology, parasite-vector dynamics, and disease risk.