Journal of Chemical Ecology

, Volume 34, Issue 7, pp 959–970

Impact of Herbivore-induced Plant Volatiles on Parasitoid Foraging Success: A Spatial Simulation of the Cotesia rubecula, Pieris rapae, and Brassica oleracea System

  • Molly Puente
  • Krisztian Magori
  • George G. Kennedy
  • Fred Gould
Article

DOI: 10.1007/s10886-008-9472-9

Cite this article as:
Puente, M., Magori, K., Kennedy, G.G. et al. J Chem Ecol (2008) 34: 959. doi:10.1007/s10886-008-9472-9

Abstract

Many parasitoids are known to use herbivore-induced plant volatiles as cues to locate hosts. However, data are lacking on how much of an advantage a parasitoid can gain from following these plant cues and which factors can limit the value of these cues to the parasitoid. In this study, we simulate the Cotesia rubecula–Pieris rapae–Brassica oleracea system, and ask how many more hosts can a parasitoid attack in a single day of foraging by following plant signals versus randomly foraging. We vary herbivore density, plant response time, parasitoid flight distance, and available host stages to see under which conditions parasitoids benefit from herbivore-induced plant cues. In most of the parameter combinations studied, parasitoids that responded to cues attacked more hosts than those that foraged randomly. Parasitoids following plant cues attacked up to ten times more hosts when they were able to successfully attack herbivores older than first instar; however, if parasitoids were limited to first instar hosts, those following plant cues were at a disadvantage when plants took longer than a day to respond to herbivory. At low herbivore densities, only parasitoids with a larger foraging radius could take advantage of plant cues. Although preference for herbivore-induced volatiles was not always beneficial for a parasitoid, under the most likely natural conditions, the model predicts that C. rubecula gains fitness from following plant cues.

Keywords

Tritrophic interactions Herbivore-induced plant volatiles Parasitoid behavior Signal utility Spatial simulation model 

Supplementary material

10886_2008_9472_MOESM1_ESM.doc (530 kb)
Table 1 Relative advantage for parasitoids that followed signals, calculated as the number of hosts attacked by parasitoids following signals minus the number attacked by parasitoids randomly foraging, divided by the number attacked by randomly foraging parasitoids. Negative numbers indicate that randomly foraging parasitoids had a higher relative advantage than parasitoids following signals (pink colors accompany negative numbers and blue colors accompany positive numbers. The color intensity reflects the magnitude of the number—see below). The columns are as follows: “Induction” is the induction delay in days, “Relaxation” is the relaxation delay in days, “Density” is the herbivore host density, “Host” is the oldest viable instar host, “Distance” refers to the distance bias of the parasitoid, and “Pattern” is which pattern the parameter combinations were classified as. In the Distance column, “Exp” refers to an exponential signal bias, and “Lin” refers to a linear signal bias (DOC 540 KB).

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Molly Puente
    • 1
  • Krisztian Magori
    • 1
    • 2
  • George G. Kennedy
    • 1
  • Fred Gould
    • 1
  1. 1.Department of EntomologyNorth Carolina State UniversityRaleighUSA
  2. 2.School of EcologyUniversity of GeorgiaAthensUSA

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