Host Specialization and Population Differentiation in Parasitoids Grant uri icon



  • Host specialization and population differentiation in parasitoids
    Pellmyr, N. Olof
    University of Idaho

    Parasites are an integral part of many ecosystems and represent much of the earth's biodiversity. Specialization to hosts has been implicated as a major factor in the immense diversification of parasitic groups, however, empirical work examining the link between specialization and diversification has been based mostly on phytophagous insects. Next to phytophagous insects, parasitoids are the second most diverse parasitic group, and are also an ecologically and economically important trophic link in terrestrial ecosystems, because they feed on many phytophagous insect species. Ongoing research on the interactions between yuccas, yucca moths, and their hymenopteran parasitoids has identified a parasitoid species amenable to testing the link between host specialization and diversification. Specifically, this study will analyze parasitoid host use patterns at several geographic scales, and evaluate how host use influences parasitoid population structure. Previous research on yucca moths has shown that specialization to plant species and microhabitat within a plant are important to moth diversification. Results from the proposed research will determine if these same factors also influence differentiation in parasitoids. One objective will test hypotheses about how host microhabitat influences the pattern of parasitoid host use at a very local scale. A second objective will evaluate parasitoid host use at a broader geographic scale, and test hypotheses on how community context influences host specificity. A final objective will test how host specificity due to host microhabitat and community context influences the pattern of parasitoid population structure obtained from molecular markers. The proposed research will incorporate the third trophic level into a well-known and well-studied plant-insect interaction that is commonly used in biology textbooks as an example of the importance of mutualisms and species interactions. Undergraduate students will be actively involved at every level of the proposed research to further their training and understanding of science by providing hands-on experience in both the field and laboratory setting.

date/time interval

  • July 15, 2003 - June 30, 2007

total award amount

  • 230,000