Female resistance and harmonic convergence influence male mating success in Aedes aegypti

Andrew Aldersley,Lauren J Cator

doi:10.1038/s41598-019-38599-3

Abstract

Despite the importance of mosquito mating biology to reproductive control strategies, a mechanistic understanding of individual mating interactions is currently lacking. Using synchronised high-speed video and audio recordings, we quantified behavioural and acoustic features of mating attempts between tethered female and free-flying male Aedes aegypti. In most couplings, males were actively displaced by female kicks in the early phases of the interaction, while flight cessation prior to adoption of the pre-copulatory mating pose also inhibited copulation. Successful males were kicked at a reduced rate and sustained paired contact-flight for longer than those that were rejected. We identified two distinct phases of acoustic interaction. Rapid frequency modulation of flight tones was observed in all interactions up to acceptance of the male. Harmonic convergence (wingbeat frequency matching) was detected more often in successful attempts, coinciding with the transition to stabilised paired flight and subsequent genital contact. Our findings provide a clearer understanding of the relationship between acoustic interactions and mating performance in mosquitoes, offering insights which may be used to target improvements in laboratory reared lines.

Highlights

Mass release of sterile and transgenic males to manage wild mosquito populations is currently being integrated into vector control programmes[1,2,3,4]
Through analysis of the structure of behavioural and acoustic interactions during mating attempts, we explored how different aspects of this process relate to the likelihood of female rejection and male mating success
Copula formation in Ae. aegypti is a complex, dynamic process involving the integration of multiple behaviours mediated by rapidly fluctuating acoustic interactions

Summary

Introduction

Mass release of sterile and transgenic males to manage wild mosquito populations is currently being integrated into vector control programmes[1,2,3,4]. Acoustic signalling—and harmonic convergence—has been proposed as a mechanism by which females may assess and determine whether to mate with a particular male It is unclear if and how harmonic convergence and RFM relate to one another[49], or how they integrate into the behavioural mating sequence. In order to build a complete picture of what drives differential mating success in mosquitoes, a more detailed knowledge of the entire mating process—including the pre-copulatory phases that lead to the formation of a mating pair and the effect of female choice activities—is needed This information is currently lacking, at least in part, due to the limitations of observing these rapid mid-air mating interactions. The steps required for a male to form a copula with the female have been largely overlooked as an important component of the mating sequence, despite being recognised as vital for achieving genital contact[21]

Methods

Results

Conclusion