Grant: Discovery Grants Program - Individual

In field crickets, Gryllus texensis, calling males attract females from a distance. But calling males also attract parasitic flies, Ormia ochracea, that deposit living maggots on calling males. Fly larvae devour the cricket in about 7 days. Calling more loudly or more often by male crickets attracts more female cricket, but more parasitic flies are also attracted. The mating behaviour of G. texensis has been strongly influenced by flies. For example, male crickets often remain silent near calling males where they intercept females attracted by the calling of other males, so-called satellite behaviour. Many previously silent males start calling just before dawn, a time when flies are less active. Male G. texensis are also much younger than female crickets. We are studying the rates of fly attraction to different types of cricket songs, the levels of parasitism in areas where different species of crickets are hosts, and the reproduction and lifespan of male crickets under different conditions of fly density. Many laboratories are now extending our studies including the neurobiology of fly hearing, complete loss of song in some crickets and the use of flies to control imported cricket pests. We also study acoustical communication in Madagascar Hissing Cockroaches, Gromphadorhina portentosa. In this species males produce loud hisses when disturbed and when fighting and courting. The intensity of male hisses is strongly correlated with body size and we are studying ways in which females evaluate males as mates based on their hisses. This program involves postdoctoral fellows, graduate and undergraduate students and collaborators at overseas universities thus contributing to the education of highly qualified personnel.