Polyandry in the dengue vector Aedes aegypti

Females of the dengue and chikungunya vector Aedes aegypti receive male-derived proteins during insemination that induce monogamy. While their refractoriness to a subsequent mating is often assumed to be instantaneous, complete, and permanent, several authors have shown that a second insemination can occur, both in laboratory and field settings. Despite evidence that females can mate more than once, the specific circumstances which lead to polyandry have seldom been examined, despite their importance for genetic mosquito control strategies. We tested the hypothesis that receptivity to a second mating depends on the duration of time after a female’s first mating and the oviposition history of the female. We found that females were most likely to accept a second insemination shortly after their first. However, their propensity to mate again decreased precipitously over 6 h, and then gradually gave way to full refractoriness. We also examined whether females may be re-inseminated after laying several batches of eggs and found rare re-insemination events after multiple gonotrophic cycles. This study provides a novel explanation for polyandrous behavior in Ae. aegypti. We discuss our results in the context of vector control strategies which rely on a thorough knowledge of the re-mating frequency of this important disease vector.