The role of courtship song in female mate choice in South American Cactophilic Drosophila

Abstract

Courtship songs have undergone a spectacular diversification in the Drosophila buzzatii cluster. Accordingly, it has been suggested that sexual selection has played a significant role in promoting rapid diversification, reproductive isolation and speciation. However, there is no direct evidence (i.e., song playback experiments with wingless males) supporting this tenet. Moreover, several studies have showed that the courtship song in the genus Drosophila is not always used in female mate choice decisions, nor plays the same role when it is taken into account. In this vein, we use an approach that combines manipulative and playback experiments to explore the importance and the role of courtship song in female mate choice in four species of the D. buzzatii cluster and one species of the closely related D. martensis cluster for outgroup comparison. We also investigate the importance of courtship song in sexual isolation in sympatry between the only semi-cosmopolitan species, D. buzzatii, and the other species of the D. buzzatii cluster. Our study revealed that the courtship song is used by females of the D. buzzatii cluster as a criterion for male acceptance or influences the speed with which males are chosen. In contrast, we showed that this characteristic is not shared by D. venezolana, the representative species of the D. martensis cluster. We also found that the studied species of the D. buzzatii cluster differ in the role that conspecific and heterospecific songs have in female mate choice and in sexual isolation. Our findings support the hypothesis that divergence in female preferences for courtship songs has played a significant role in promoting rapid diversification and reproductive isolation in the D. buzzatii cluster. However, evidence from D. venezolana suggests that the use of the courtship song in female mate choice is not a conserved feature in the D. buzzatii complex.

The evolution of male and female mating preferences in Drosophila speciation*

“…; Yukilevich et al. ; Iglesias and Hasson ). However, many questions remain about the genetic and evolutionary mechanisms of female preference divergence between allopatric populations.…”

“…Allopatric divergence in female copulation preferences can be driven by sexual selection, genetic drift or natural selection (Coyne and Orr 2004). Within Drosophila, females typically target divergent male cuticular hydrocarbons (Higgie et al 2000;Rundle et al 2005;Dyer et al 2014;Chung et al 2014) and/or male courtship songs (Tomaru et al 1995;Ritchie et al 1999;Yukilevich et al 2016;Iglesias and Hasson 2017). However, many questions remain about the genetic and evolutionary mechanisms of female preference divergence between allopatric populations.…”

The influence of developmental environment on courtship song in cactophilic Drosophila

“…On the one hand, D. buzzatii uses prickly pears as primary hosts and its mate recognition system relies heavily on the courtship song. On the other hand, D. koepferae primarily exploits columnar cacti and uses nonacoustic cues for mate recognition and the courtship song for mate choice (Hasson et al, 1992;Fanara et al, 1999;Iglesias & Hasson, 2017). Our results show first that variation in song parameters are not driven by allometric relationships with wing or body size; second that much of the variation in courtship song would be genetically determined; and third that host environment during development alters the quality of courtship songs in D. koepferae, but not in D. buzzatii.…”

“…The floor of the chamber was the microphone itself and had a foam cap in the opposite extreme where flies were introduced. For more details, see Iglesias & Hasson (2017).…”

“…In this sense, Morley et al (2012) demonstrated that the mechanical sensitivity of the arista changes as a function of the angle of incidence of the acoustic stimulus. Suggestively, males of D. buzzatii produce secondary songs later in courtship and immediately before copulation (Oliveira et al, 2013;Iglesias & Hasson, 2017).…”