To specialize or not to specialize: Host use and genetic differentiation in the insect community associated with yuccas

The enormous diversity of plant feeding insects has been exploited by parasitoid wasps. Almost every insect species has at least one parasitoid species. Host associated differentiation has been a major factor in determining both population structure and speciation in herbivorous insects but its influence on parasitoid taxa is unclear. Using the moth-parasitoid community on yucca plants, I examine the role of host associated differentiation in structuring a parasitoid-host community. Data on host range and genetic structure for both groups demonstrate that specialization and host associated differentiation may have a more prominent role in the evolutionary ecology of herbivorous insects than in their associated parasitoids. I explore the potential mechanisms for such an outcome.