Spatial scale, neighbouring plants and variation in plant volatiles interactively determine the strength of host–parasitoid relationships

Yavanna Aartsma*, Silvia Pappagallo, Wopke van der Werf, Marcel Dicke, Felix J.J.A. Bianchi, Erik H. Poelman

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Species-specific responses to the environment can moderate the strength of interactions between plants, herbivores and parasitoids. However, the ways in which characteristics of plants, such as genotypic variation in herbivore induced volatiles (HIPVs) that attract parasitoids, affect trophic interactions in different contexts of plant patch size and plant neighbourhood is not well understood. We conducted a factorial field experiment with white cabbage Brassica oleracea accessions that differ in the attractiveness of their HIPVs for parasitoids, in the context of different patch sizes and presence or absence of surrounding Brassica nigra plants. Parasitism rates of experimentally introduced Pieris brassicae caterpillars and the presence of naturally occurring Pieris spp. caterpillars in the plots were assessed throughout the growing season. The abundance of Pieris caterpillars was neither affected by cabbage accession nor plot size. Later in the season, when B. nigra plants had senesced, fewer caterpillars were found on cabbage plants in plots with a B. nigra border. Parasitism rates fluctuated over the season, and were not affected by plot size. However, the B. nigra border negatively affected parasitism rates on the accession that is less attractive to the parasitoid Cotesia glomerata, but not on the more attractive accession. Our results show that plant variation in HIPVs can differentially influence herbivores and parasitoids depending on characteristics of the surrounding vegetation context. These findings underscore the importance of considering the interaction between focal plant traits and neighbourhood context to reliably predict trophic cascades.

Original languageEnglish
Pages (from-to)1429-1439
JournalOikos
Volume129
Issue number9
Early online date2 Jun 2020
DOIs
Publication statusPublished - Sep 2020

Keywords

  • herbivore-induced plant volatiles
  • host–parasitoid interactions
  • insect–plant interactions
  • plant neighbourhood

Fingerprint Dive into the research topics of 'Spatial scale, neighbouring plants and variation in plant volatiles interactively determine the strength of host–parasitoid relationships'. Together they form a unique fingerprint.

Cite this