Polyandry Depends on Postmating Time Interval in the Dengue Vector Aedes aegypti

Abstract

Aedes aegypti is the primary vector of the dengue and chikungunya viruses. After mating, male seminal fluid molecules cause females to become unreceptive to a subsequent mating. This response is often assumed to be immediate and complete, but a growing body of evidence suggests that some females do mate more than once. It is unknown how quickly a female becomes unreceptive to a second mating. Furthermore, the degree to which she remains monandrous after laying several batches of eggs has not been rigorously tested. Therefore, we assessed the rates of polyandry in two sets of experiments using wild-type males and those with fluorescent sperm. The first experiment tested the likelihood of polyandry after postmating intervals of various durations. Most females became refractory to a second mating within 2 hours after mating, and rates of polyandry ranged from 24% immediately after mating to 3% at 20 hours after mating. The second experiment tested whether females were polyandrous after cycles of blood meals and oviposition. No re-insemination was found after one, three, or five such cycles. This study is the first to demonstrate that polyandrous behavior depends on the postmating interval. Our results will inform future applications that depend on an accurate knowledge of Ae. aegypti mating behavior, including models of gene flow, investigations of molecules that drive female mating behavior, and control strategies that deploy genetically modified mosquitoes into the field.

A Peptide Signaling System that Rapidly Enforces Paternity in the Aedes aegypti Mosquito

“…aegypti are generally monandrous [1, 3], which poses the question of how remating is rapidly suppressed, and how the paternity of the first male is enforced (Figure 2B). We used remating assays in which groups of females were sequentially exposed to males of two different genotypes, and the paternity of the offspring determined.…”

“… SUMMARY Female Aedes aegypti mosquitoes typically mate only once with one male in their lifetime, a behavior known as “monandry” [1]. This single mating event provisions the female with sufficient sperm to fertilize the >500 eggs she will produce during her ~4–6-week lifespan in the laboratory [2].…”

“…Ae. aegypti mate in flight near human hosts [6], and females become refractory to remating within seconds [1, 3, 4], suggesting the existence of a rapid mechanism to prevent female remating. In this study we implicate HP-I, an Aedes - and male-specific peptide transferred to females [7], and its cognate receptor in the female, NPYLR1 [8], in rapid enforcement of paternity.…”

Using spatial genetics to quantify mosquito dispersal for control programs

“…half-sisters share a father, not a mother) given that Ae. aegypti females rarely mate more than once [34,35]. We assume that 3 rd degree relatives are first cousins, given that a category like great-grandparent/great-grandoffspring is very unlikely in our sampling scheme.…”

A mosquito sperm's journey from male ejaculate to egg: Mechanisms, molecules, and methods for exploration

“…While mosquito sperm do not form conjugated groups like other taxa (Hayashi, 1998;Higginson et al, 2012), it is possible that mosquito sperm reduce drag by swimming in parallel, allowing for their faster storage in the spermathecae. Females of some mosquitoes may occasionally mate more than once (Boyer et al, 2012;Richardson et al, 2015), especially soon after their first mating (Degner and Harrington, 2016). Therefore, males whose sperm fill the spermathecae quickly may reduce their risk of sharing paternity with a second male.…”