Dangles Olivier auteur aut IRD Herrera M. auteur aut IRD Anthelme Fabien auteur aut IRD text journalArticle eng text/pdf born digital access The stress-gradient hypothesis (SGH) postulates an increase in the frequency of positive species interactions at increasing amounts of stress. While the SGH has been extensively tested in plant-plant interactions along abiotic stresses, it remains unclear whether this hypothesis could apply to higher trophic levels, such as herbivores, along biotic stress gradients. To address this issue, we investigated how the interaction between two potato herbivores may change along a stress gradient created by an assortment of potato varieties with different tuber palatability. We used a tuber resistance trait as a measure for biotic stress and one herbivore as the facilitator to gain access to the tuber of the other herbivore. Our experiment revealed a switch from neutral to positive interactions with increasing stress, confirming for the first time the predictions of the SGH for herbivores. Moreover, the intensity of facilitation decreased at high stress levels, suggesting that benefits by the facilitating species were dampened in the most stressful environment. In view of the ubiquitous role played by positive interactions among herbivores, broadening our search image for facilitative effects among other plant enemies will allow a better awareness of the importance of the SGH in structuring plant communities. specialized biotic stress facilitation plant antagonists species interaction stress-gradient hypothesis (SGH) 082 197 2 405-408 2013 0028-646X https://www.documentation.ird.fr/hor/fdi:010058873 10.1111/nph.12080 0028-646X [F B010058873] https://www.documentation.ird.fr/hor/fdi:010058873 https://www.documentation.ird.fr/intranet/publi/2013/02/010058873.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2013-03-06 2017-08-23 fdi:010058873 fre