DIFFERENTIAL CANNIBALISM AND POPULATION-DYNAMICS IN A HOST-PARASITOIDSYSTEM

The effects of host cannibalism on a host-parasitoid system were explo red through experiment and modelling. In individual encounters between parasitized and unparasitized Plodia interpunctella larvae, parasitiz ed larvae were more likely to be cannibalized. Inclusion of this diffe rential cannibalism into a simple Lotka-Volterra-type model of host-pa rasitoid population dynamics generates alternative stable states inclu ding stable coexistence and extinction of the parasitoid - which depen d on starting conditions. Possible mechanisms for differential canniba lism, and its implications for studies of host-parasitoid are discusse d.