Evolutionary and population dynamics of host-parasitoid interactions

The role of evolutionary dynamics in understanding host-parasitoid interact ions is interlinked with the population dynamics of these interactions. Her e, we address the problems in coupling evolutionary and population dynamics of host-parasitoid interactions. We review previous theoretical and empiri cal studies and show that evolution can alter the ecological dynamics of a host-parasitoid interaction. Whether evolution stabilizes or destabilizes t he interaction depends on the direction of evolutionary changes, which are affected by ecological, physiological, and genetic details of the insect bi ology. We examine the effect of life history correlations on population per sistence and stability, embedding two types, one of which is competitively inferior but superior in encapsulation (for parasitoid, virulence), in a Ni cholson-Bailey model with intraspecific resource competition for host. If a trade-off exists between intraspecific competitive ability and encapsulati on (or virulence, as a countermeasure) in both the host and parasitoid, the trade-off or even positive correlation in the parasitoid is less influenti al to ecological stability than the trade-off in the host. We comment on th e bearing this work has on the broader issues of understanding host-parasit oid interactions. including long-term biological control.