Ecological dissociation and re-association with a superior competitor alters host selection behavior in a parasitoid wasp

Dhaval K. Vyas*, Jeffrey A. Harvey, Ryan L. Paul, George E. Heimpel, Paul J. Ode

*Corresponding author for this work

    Research output: Contribution to JournalArticleAcademicpeer-review

    7 Downloads (Pure)


    Interspecific competition for limited resources can drive ecological specialization and trait expression. Organisms released from intense competition may exploit a broader range of resources, but if reunited with stronger competitors, survivorship may depend on foraging behaviors that reduce competition. We compared the host selection behavior of the parasitoid Cotesia glomerata from two North American populations that differ in their association with Cotesia rubecula, a superior competitor. Both parasitoids originate from Europe and attack the imported cabbageworm (a.k.a. small cabbage white) Pieris rapae, but C. glomerata was introduced into North America almost a century before C. rubecula. After re-association in North America, C. rubecula has displaced C. glomerata in several regions, but not in other regions. Host selection was measured in female C. glomerata from Maryland (MD) where it coexists with C. rubecula, and in conspecifics from Colorado (CO) where C. rubecula is absent. Unparasitized and C. rubecula-parasitized P. rapae hosts were used in choice tests to examine whether C. glomerata host selection behavior differed based on the population’s association history with C. rubecula. We found that C. glomerata from MD had a higher likelihood of avoiding hosts parasitized by C. rubecula (and thus avoiding competition) than did wasps from CO. The ability of C. glomerata to avoid hosts parasitized by C. rubecula may facilitate coexistence in MD; whereas, the lack of discrimination in CO populations of C. glomerata naïve to C. rubecula could contribute to the displacement of C. glomerata were C. rubecula to enter the same habitat.

    Original languageEnglish
    Pages (from-to)261-270
    Number of pages10
    Issue number2
    Early online date24 Jul 2019
    Publication statusPublished - Oct 2019


    We are grateful to personnel at Calvert Farm, Calvert Gift Farm, Flying Plow, Glade Link Farm and Gorman Farm for allowing us to collect insects from their crops; and to the staff at CSU ARDEC for helping to maintain our plants. Many thanks also to the staff at the Colorado State University Plant Growth Facilities for providing support in rearing plant and insect colonies. We thank H.L. Gray and J.J. Weis for their assistance in collecting C. rubecula near the University of Minnesota. Financial support was granted through the United States Department of Agriculture NIFA AFRI: 2014-67013- 2172 to P.J.O and G.E.H. Additional funding was provided to D.K.V. by the William M. Brown Professional Development Award, Sigma Xi (Grant no. G201603152036938) and the Colorado State University Graduate Degree Program in Ecology.

    FundersFunder number
    United States Department of Agriculture NIFA AFRI2014-67013- 2172
    Colorado State University
    Sigma XiG201603152036938


      • Competition
      • Cotesia glomerata
      • Cotesia rubecula
      • Foraging behavior
      • Pieris rapae


      Dive into the research topics of 'Ecological dissociation and re-association with a superior competitor alters host selection behavior in a parasitoid wasp'. Together they form a unique fingerprint.

      Cite this