Predators induce interspecific herbivore competition for food in refuge space

Citation
A. Pallini et al., Predators induce interspecific herbivore competition for food in refuge space, ECOL LETT, 1(3), 1998, pp. 171-177
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
ECOLOGY LETTERS
ISSN journal
1461-023X → ACNP
Volume
1
Issue
3
Year of publication
1998
Pages
171 - 177
Database
ISI
SICI code
1461-023X(199811)1:3<171:PIIHCF>2.0.ZU;2-K
Abstract
Resource competition among herbivorous arthropods has long been viewed as u nimportant because herbivore populations are controlled by predators. Altho ugh recently resurrected as an organizing force in arthropod communities on plants, there is still general agreement that resource competition among h erbivores is reduced by predators. Here we show the reverse: predators indu ce interspecific resource competition among herbivores. We found that thrip s larvae (Frankliniella occidentalis) use the web produced and inhabited by the spider mite Tetranychus urticae as a refuge from predation by the phyt oseiid mite Neoseiulus curumeris. Thrips larvae prefer clean plant parts, b ut move into the web upon perceiving volatile cues associated with thrips a nd predators. This behaviour leads to lower predation risk, but also to red uced developmental rate and lower production of thrips larvae due to compet ition with spider mites. In addition, thrips larvae consume spider-mite egg s. Thus, predators induce interspecific competition and intraguild predatio n among herbivores within refuge space, even when host plants have an overa ll green appearance.