Functional Ecology of Calling and Mating in the Cricket Species (Acheta domesticus and Telogryllus commodus)

Whole organism performance traits are measures of an organism’s ability to complete dynamic functions relevant to fitness within the contexts of both sexual and natural selection. Performance capacities are subject to allocation based life history trade-offs, but are also frequently implicated in signaling via visual or auditory displays, many of which are sexually dimorphic. But although performance traits are known to influence the outcome of male combat interactions, the effect of performance on mating interactions is poorly understood. Recently, the invertebrate neurotransmitter octopamine has been shown to affect performance expression in house crickets independent of the underlying morphology, raising the possibility that performance traits can be manipulated by altering the pharmacological milieu by simple dietary supplementation or, in the case of crickets, by antennae removal. I used these approaches to test for and demonstrate functional role of a performance trait, bite force, in determining the course and outcome of mating interactions in Acheta domestic house crickets. I also found that blocking octopamine receptors with an antagonist (epinastine) significantly affects courtship call structure. Based on manipulation of the neurotransmitter octopamine, I found that dampening octopermegenic receptors affected male calling effort and the dominantly expressed frequency of courtship calls during mating interactions. Finally, I showed that antennae removal alters the relationships among overall calling effort; lifespan; and metabolic rate within Telogryllus commodus crickets