Quantity and quality of available mates alters female responsiveness but not investment in the Pacific field cricket, Teleogryllus oceanicus

Abstract

An individuals’ experience with conspecific signaling during development can lead to variation in their mating signals and behavior later in life. It is unclear whether experience with sexual signals also alters receivers’ fitness through changes in investment in offspring. Male field crickets attract mates using a long-distance calling song. To determine how developmental experience with calling song quality and quantity alters mating responsiveness and fitness, we raised juvenile female Teleogryllus oceanicus in five acoustic environments. These environments mimicked two mate quantities (high and low) crossed with two mate qualities (high and low), and a silent control. At adulthood, we measured females’ responsiveness in phonotaxis trials. Following phonotaxis, females were offered opportunities to mate and lay eggs. We measured egg number and proportion hatching as components of fitness and reproductive investment. Corroborating previous research in this system, female crickets raised in silence approached a broadcast calling song nearly 45% faster than their counterparts reared hearing a high-quantity/high-quality combination of calling song. Additionally, females adjusted other aspects of phonotaxis behavior in response to the quantity, but not quality of song. We found no evidence that females adjusted mating rates or investment in offspring. Regardless of acoustic experience, females laid equivalent numbers of eggs that had equivalent hatching success. Our results show that female mating behavior responds to juvenile experience mimicking a lack of mating opportunities, but is less responsive to variation in mate quality. Furthermore, reproductive investment may be less plastic than mating behavior. Social experience can inform organisms about current environmental conditions and lead to changes in behavior. Existing work suggests that field crickets in the genus Teleogryllus change their mating behavior in response to acoustic environments that mimic varied mate availabilities and qualities. However, we do not know if females alter their investment in offspring under similar circumstances. Variable investment could speed evolutionary change when combined with behavioral plasticity. We found that although female mating behavior is sensitive to variation in acoustic experience, reproductive investment is not. The number of eggs laid and the percent hatching did not depend on acoustic experience. We discuss evolutionary explanations for these patterns, including the possibility that investment is less plastic than mating behavior.