League, G. P. | Search bioRxiv

bioRxiv2021

Synchronized swarming: Harmonic convergence and acoustic mating dynamics in the malaria mosquito Anopheles gambiae

The mosquito Anopheles gambiae is a major African malaria vector, transmitting parasites responsible for significant mortality and disease burden. Malaria declines have stagnated recently due to widespread insecticide resistance among vector populations. Flight acoustics are essential to mosquito mating biology and represent promising alternative targets for mosquito control. However, mosquito swarm acoustics data are limited. 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 elevated male or female flight tone frequencies and amplitudes during swarming flight with gradual declines to pre-swarm levels over an approximately 35-min period. Analysis of mixed-sex swarms revealed additional increases in flight tone frequencies and amplitudes due to mating activity. Data from mixed-sex swarms suggest harmonic convergence during swarming enhances the efficiency of female detection by synchronizing male and female baseline swarm tones. Further, data from experiments using female swarm tone playbacks to males indicate that harmonic convergence during mating interactions coordinates male scramble competition by acoustically masking mating couple flight tones. These findings advance our knowledge of mosquito swarm acoustics, providing vital information for reproductive control strategies.

animal behavior and cognition↗

bioRxiv2020

Sexual selection theory meets disease vector control: Testing harmonic convergence as a "good genes" signal in Aedes aegypti mosquitoes

The mosquito Aedes aegypti is a medically important, globally distributed vector of the viruses that cause dengue, yellow fever, chikungunya, and Zika. Although reproduction and mate choice are key components of vector population dynamics and control, our understanding of the mechanisms of sexual selection in mosquitoes remains poor. In "good genes" models of sexual selection, females use male cues as an indicator of both mate and offspring inherent genetic quality. Recent studies in Ae. aegypti provide evidence that male wingbeat acoustics signal aspects of offspring quality and performance during mate selection in a process known as harmonic convergence. However, the extent to which harmonic convergence may signal overall inherent quality of mates and their offspring remains unknown. To examine this, we measured the potential acoustic signaling and heritability of a broad panel of parent and offspring fitness traits in two generations of field-derived Ae. aegypti originating from dengue endemic field sites in Thailand. Our data show that in this population of mosquitoes, harmonic convergence does not signal male fertility, female fecundity, and male flight performance traits, which despite displaying robust variability in both parents and their offspring were only weakly heritable. Together with previous work, our findings suggest that vector reproductive control programs should treat harmonic convergence as an indicator of some, but not all aspects of inherent quality, and that multiple forms of sexual selection are likely at play in Ae. aegypti in a trait, population, and environment dependent manner.

ecology↗