Size, sounds and sex: interactions between body size and harmonic convergence signals determine mating success in Aedes aegypti

Abstract

BackgroundSeveral new mosquito control strategies will involve the release of laboratory reared males which will be required to compete with wild males for mates. Currently, the determinants of male mating success remain unclear. The presence of convergence between male and female harmonic flight tone frequencies during a mating attempt have been found to increase male mating success in the yellow fever mosquito, Aedes aegypti. Size has also been implicated as a factor in male mating success. Here, we investigated the relationships among body size, harmonic convergence signalling, and mating success. We predicted that harmonic convergence would be an important determinant of mating success and that large individuals would be more likely to converge.MethodsWe used diet to manipulate male and female body size and then measured acoustic interactions during mating attempts between pairs of different body sizes. Additionally, we used playback experiments to measure the direct effect of size on signalling performance.ResultsIn live pair interactions, harmonic convergence was found to be a significant predictor of copula formation. However, we also found interactions between harmonic convergence behaviour and body size. The probability that a given male successfully formed a copula was a consequence of his size, the size of the female encountered, and whether or not they converged. While convergence appears to be predictive of mating success regardless of size, the positive effect of convergence was modulated by size combinations. In playbacks, adult body size did not affect the probability of harmonic convergence responses.ConclusionsBoth body size and harmonic convergence signalling were found to be determinants of male mating success. Our results suggest that in addition to measuring convergence ability of mass release lines that the size distribution of released males may need to be adjusted to complement the size distribution of females. We also found that diet amount alone cannot be used to increase male mating success or convergence probability. A clearer understanding of convergence behaviours, their relationship to mating success, and factors influencing convergence ability would provide the groundwork for improving the mating performance of laboratory reared lines.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1914-6) contains supplementary material, which is available to authorized users.

A Novel Methodology For Recording Wing Beat Frequencies of Untethered Male and Female Aedes aegypti

“…Adult size, which can be influenced by larval food availability and temperature exposure, has been found to influence mosquito WBFs, with larger individuals displaying higher WBFs in some studies (Costello 1974, Wekesa et al 1998, Cator et al 2010. To determine the ability of the ultrasonic system to detect changes in WBF related to differences in body size, we reared cohorts under different feeding regimes to generate ''small'' and ''large'' sized males and females following the methods of Cator and Zanti (2016). In short, cohorts of 500 1st instars were subjected to either ''high'' or ''low'' food treatments to produce large or small adults.…”

Sexual behaviour and morphological variation in the millipede Megaphyllum bosniense (Verhoeff, 1897)

“…Morphological variation of somatic and genital traits may have significant impact on mating success in many animal groups (Langerhans et al, 2005;Ponlawat and Harrington, 2009;Cator and Zanti, 2016). Somatic traits are under the influence of precopulatory sexual selection (Jones and Ratterman, 2009), while sexual traits can be subjected to both pre-and postcopulatory selection (Polihronakis, 2006;Kamimura, 2014;Simmons, 2014).…”

Mating behaviour and its relationship with morphological features in the millipede Pachyiulus hungaricus (Karsch, 1881) (Myriapoda, Diplopoda, Julida)

“…The existence of such patterns of morphological variability may lead to intrasexual variation in mating tactics and/ or mating success. Indeed, many studies have shown that overall body size Austad, 1990, 1994;Wedell, 1991;Simmons et al, 1996;Wenninger and Averill, 2006;Pavković-Lučić et al, 2009;Helinski and Harrington, 2011;Cator and Zanti, 2016) correlates to male mating and fertilisation success. Additionally, it has been shown that variation in characteristics of mating sequences, such as copulation duration, may be a factor that influences male fertilisation success (Simmons and Parker, 1992;Arnqvist and Danielsson, 1999a;Andrés and Cordero Rivera, 2000;Jones et al, 2006).…”