9509738 Taylor Parasitoids are insect species in which females lay eggs in or on other insects, which then are eaten by the parasitoid larvae. In most species the hosts are attacked in immature stages and are killed before reaching reproductive maturity. Many species of fly parasitoids, however, attack adult hosts, which often reproduce before being killed. This project will describe such nonlethal parasitism by one such species, Trichopoda pennipes, on its host, the southern green stink bug. Laboratory experiments and rearing of parasitized hosts from field collections will be used to describe the effects of parasitism on host mortality and reproduction and on the success of parasitoid reproduction, in relation to factors such as the age of the host when parasitized and the number of parasitoid eggs laid on it. Preferences of parasitoids for hosts of different ages also will be determined. The probable effects of these processes on the population dynamics of the parasitoid-host system will be analyzed with mathematical models. Parasitoids are important sources of pest control in agricultural and other ecological systems. The host species to be used in these studies is an important agricultural pest worldwide, and the parasitoid specie has often been used as a biological control agent for it, though with limited success. This research will lead to better understanding of factors, particularly non-lethal parasitism, affecting the ability of this and other parasitoids to control their hosts. This knowledge should enhance the effectiveness of biological pest control efforts and thus reduce our dependence on chemical insecticides.
