In numerous organisms, mating causes changes in females that are required for females to successfully generate offspring. These changes are typically both behavioral and physiological. Although non-sperm components of the male ejaculate cause the post-mating changes, they can often be altered by other factors, such as the age of the mating individuals. In insects, females often do not mate for 1-2 days after their emergence from pupae and suffer declines in fertility with increased age. Here, we determined how long after emergence from pupae female Ae. aegypti first mate and take a blood meal, as blood feeding not only provides nutrients for egg development, but also allows this species to transmit viruses. We found that females require ∼24 hours to mate, but blood-feed as shortly as 14 hours after emergence. We next examined the fertility of recently emerged females (30-41 hours-old) and of “old” females (2- and 3-week-old), finding that females are fully fertile once they become receptive to mating, but suffer declines in fertility with increased age, like in other insects. Our results suggest that females can blood-feed shortly after becoming adults, enabling females to potentially consume a virus infected blood-meal shortly after their emergence.

Mating induces behavioral and physiological changes in female insects—collectively referred to as the female post-mating response (PMR)—that facilitate the production of progeny. PMRs are elicited by transfer of male-derived seminal components during mating, but are altered by other factors, including adult age. Increased female age is often accompanied by declines in fertility. However, mating shortly after emergence also impacts fertility in the insect model Drosophila melanogaster. Here, we determined the age post-emergence when females of the vector mosquito Aedes aegypti can be inseminated and blood-feed. We next examined fecundity, fertility, and the storage of sperm in the female reproductive tract in “young” (10-41 hours-old) and “old” (2- and 3-week-old) females, finding that blood-feeding began at 14 hours, and mating at ∼24 hours post-emergence. Although young females consumed smaller blood quantities and stored fewer sperm, they were similarly fertile to 4-day-old controls. Old females, however, suffered significant declines in fecundity by 2 weeks of age. Our results show that female Ae. aegypti start to become sexually receptive 1 day after their emergence, but can ingest blood much sooner, suggesting that mating is not a prerequisite to blood-feeding, and that females can ingest an arbovirus infected blood-meal shortly after emergence.