Spatial and Temporal Heterogeneity of Host-Parasitoid Interactions in Lupine Habitat

Doctoral Dissertation -- Applied Mathematics -- University of California, Davis. The inhabitants of the bush lupine in coastal California have been the subject of scientific scrutiny in recent years. Observations of a host-parasitoid interaction in the shrub's foliage record stable spatial patterns in a fairly homogeneous environment. Near the root of the lupine, another host-parasitoid interaction is also of considerable interest. In some cases this interaction has been observed to be much more persistent than suggested by mathematical models. In this work, a discrete-time spatial model of the first host-parasitoid system is introduced. We analyze the model, describing its transient behavior and finding the conditions under which spatial patterns occur, as well as an estimate of outbreak size under those conditions. We also explore one possible explanation for the persistence of the second host-parasitoid system.