Alternative male strategies: genetic differences in crickets

Area of Science:

• Behavioral Ecology
• Evolutionary Genetics
• Animal Behavior

Background:

• Male field crickets (Gryllus integer) display alternative mating strategies: acoustic signaling (calling) and stealthy interception of females attracted to calling males.
• Understanding the genetic architecture of these alternative reproductive behaviors is crucial for evolutionary studies.

Purpose of the Study:

• To investigate the genetic basis of nightly calling duration in male field crickets.
• To determine if selection can shape distinct genetic substrates for alternative male mating behaviors.

Main Methods:

• Implemented artificial selection experiments on male field crickets, creating high and low calling duration lines.
• Measured and compared the mean nightly calling times between selected lines.
• Calculated realized heritabilities for calling duration in both selected lines.

Main Results:

• Significant differences in mean nightly calling duration were observed between the high and low selection lines.
• Realized heritabilities for calling duration were high, estimated at 0.50 for the high line and 0.53 for the low line.
• These results indicate a substantial genetic component influencing the duration of male calling behavior.

Conclusions:

• The duration of nightly calling in male field crickets is strongly influenced by genetics.
• Selective breeding can effectively differentiate populations based on calling behavior, associating specific genetic substrates with alternative reproductive strategies.
• This study provides evidence for the genetic basis of alternative mating behaviors in a single species, a finding not yet demonstrated in other species with contrasting male reproductive modes.