Harmonic convergence coordinates swarm mating by enhancing mate detection in the malaria mosquito Anopheles gambiae

Abstract

The mosquito Anopheles gambiae is a major African malaria vector, transmitting parasites responsible for significant mortality and disease burden. Although flight acoustics are essential to mosquito mating and present promising alternatives to insecticide-based vector control strategies, there is limited data on mosquito flight tones during swarming. Here, for the first time, we present detailed analyses of free-flying male and female An. gambiae flight tones and their harmonization (harmonic convergence) over a complete swarm sequence. Audio analysis of single-sex swarms showed synchronized elevation of male and female flight tones during swarming. Analysis of mixed-sex swarms revealed additional 50 Hz increases in male and female flight tones due to mating activity. Furthermore, harmonic differences between male and female swarm tones in mixed-sex swarms and in single-sex male swarms with artificial female swarm audio playback indicate that frequency differences of approximately 50 Hz or less at the male second and female third harmonics (M2:F3) are maintained both before and during mating interactions. This harmonization likely coordinates male scramble competition by maintaining ideal acoustic recognition within mating pairs while acoustically masking phonotactic responses of nearby swarming males to mating females. These findings advance our knowledge of mosquito swarm acoustics and provide vital information for reproductive control strategies.

The pitfalls of regression to the mean in bivariate timeseries analysis

“…For example, if individuals positioned on opposite sides of their respective means become in absolute terms, this may create the impression of deliberate trait convergence – that is, the movement of traits towards each other – in mated pairs or other social partners. This may be interpreted as an adaptive strategy to increase similarity, as it has been species ranging from mosquitos (Aldersley et al, 2016; Garcia Castillo et al, 2021) to humans (Anderson et al, 2003; Sjaarda & Kutalik, 2022).…”

“…Correlations between two timeseries – that is, sequences of observations measured across time – are commonly interpreted as reflecting stable relationships, where one variable causes corresponding shifts in the other (Bergmüller & Taborsky, 2010; Dingemanse & Araya-Ajoy, 2015). In mated pairs or social partners, synchronised trait changes are seen as efforts to increase social cohesion (Anderson et al, 2003; Bergmüller & Taborsky, 2010; Garcia Castillo et al, 2021; Gray & Ozer, 2019; Laubu et al, 2016; Sjaarda & Kutalik, 2022). In individuals, traits that change in apparent coordination are viewed as indicative of “integrated phenotypes” originating from coevolution (Nielsen & Papaj, 2022; Sheehy & Laskowski, 2023).…”

Effect of age on wingbeat frequency of Aedes aegypti and potential application for age estimation of mosquitoes

“…Prior to copulation, males swarm to locate female mosquitoes by hearing and following their flight tones (Somers et al, 2022), and through a process called harmonic convergence the mating pairs actively match their flight tones at a shared harmonic frequency. (Garcia Castillo et al, 2021; Somers et al, 2022). As a result of advances in mosquito vector acoustics, scientists have developed traps that mimic flight tones of female mosquitoes to attract male mosquito as a surveillance method (Jakhete et al, 2017; Johnson et al, 2018; Johnson & Ritchie, 2016).…”

“…Prior to copulation, males swarm to locate female mosquitoes by hearing and following their flight tones (Somers et al, 2022), and through a process called harmonic convergence the mating pairs actively match their flight tones at a shared harmonic frequency. (Garcia Castillo et al, 2021;Somers et al, 2022).…”