Influence of Male Songs on Female Mating Behavior in the Grasshopper Chorthippus biguttulus (Orthoptera: Acrididae)

In males of the grasshopper Chorthippus biguttulus the relationship between song and mating success was investigated in three isolated field populations of individually marked animals within their natural habitat. In a population with muted males (forewings removed), females mated on average 1.7 days later than in a population with intact males. But approximately 14 days after the imaginal moult, roughly corresponding with the time of the first oviposition, 100% of females in both populations had mated. In a further test population, females with a choice between singing and mute males mated almost exclusively (16 from 17 observed copulations) with the intact, singing males. The chance encounter frequency of a male and female was equally high for all populations (on average one encounter every 1.2 h). Different encounter probabilities cannot therefore have caused either mating delay in the population with muted males or preferential selection of intact partners.