Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): John D. Reeve; James T. Cronin; Donald R. Strong
    Date: 1994
    Source: Journal of Animal Ecology 63: 912-920
    Publication Series: Miscellaneous Publication
    PDF: View PDF  (1.0 MB)

    Description

    1. In warm climates many insects exhibit discrete generations, in the absence of obvious factors that could synchronize their age structure.It has been hypothesized that parasitoid wasps might be responsible for these oscillations in the host age structure, known as generation cycles. 2. We examine the role of the parasitoid Anagrus delicatus in the dynamics of the salt-marsh planthopper Prokelisia marginata.In particular, we evaluate the hypothesis that Anagrus contributes to the formation of generation cycles in the hopper, in the subtropical climate of Florida. 3. Two kinds of evidence are presented.First, we construct continuous-time models of the system that incorporate what is known about Anagrus foraging behaviour, the life cycles of host and parasitoid, and their movements.We then examine the behaviour of these models to determine if Anagrus has the potential to induce generation cycles.We also show how spatial variation in the risk of parasitism can generate "pseudo-interference" in our continuous-time framework.Secondly, we examine the temporal pattern of host and parasitoid abundance, and parasitism rates in the field.In Anagrus were contributing to the formation of generation cycles, we would expect to see a characteristic pattern of abundance and mortality from parasitism. 4. Both our modeling and empirical results suggest that Anagrus contributes to generation cycles in Prokelisia.Anagrus has the theoretical prerequisites for generation cycles to occur and in the field generates a cyclic pattern of parasitism that would help induce generation cycles in the planthopper. 5. The existence of an adult host stage that is invulnerable to parasitism strongly influences the stability of our models.Without this stage Anagrus cannot fully stabilize the system, even if the risk of parasitism varies greatly from patch to patch.

    Publication Notes

    • You may send email to pubrequest@fs.fed.us to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

    Citation

    Reeve, John D.; Cronin, James T.; Strong, Donald R. 1994. Parasitism and generation cycles in a salt-marsh planthopper. Journal of Animal Ecology 63: 912-920

    Keywords

    Anagrus delicatus, generation cycles, host-parasitoid dynamics, planthopper, stability

    Related Search


    XML: View XML
Show More
Show Fewer
Jump to Top of Page
https://www.fs.usda.gov/treesearch/pubs/575