A cover crop alters the trophic positions of generalist predators in the litter of a banana agroecosystem

Duyck Pierre François, Lavigne Anaïs, Mollot Grégory, Vinatier Fabrice, Achard Raphaël, Okolle Justin, Tixier Philippe. 2010. A cover crop alters the trophic positions of generalist predators in the litter of a banana agroecosystem. In : 58th Annual Meeting Entomological Society of America, San Diego, USA,12-15 December 2010. s.l. : s.n., Résumé, 1 p. Annual Meeting Entomological Society of America. 58, San Diego, États-Unis, 12 Décembre 2010/15 Décembre 2010.

Résumé : Generalist predators can play an important role in agroecosystems by controlling herbivores via top-down effects. As cover crops are increasingly used in agroecosystems, the effects of this resource on generalist predator diet need to be evaluated. We studied the effect of adding a cover crop, Brachiaria decumbens, on food web structure in a banana agroecosystem by analysing stable isotopic variation in C and N for Cosmopolites sordidus, a major banana pest, and its potential predators (spiders, ants, centipedes, and earwigs). Addition of the new resource did not alter the trophic niche of the banana pest C. sordidus, indicating the absence of a direct bottom-up effect of B. decumbens on C. sordidus populations. In contrast, addition of the cover crop altered the trophic position (as indicated by ?13C signature) of the generalist predators. As a new resource that supports a more diverse community of insect herbivores, the cover crop provided alternative resources for the generalist predators. The failure of the cover crop to increase the ? 15N signature is inconsistent with the hypothesis that the cover crop would increase intraguild predation. By providing alternative prey, the addition of a new resource in agroecosystems has the potential to increase populations of generalist predators and therefore pest control. (Texte intégral)

Classification Agris : H10 - Ravageurs des plantes
F08 - Systèmes et modes de culture

Auteurs et affiliations

• Duyck Pierre François, CIRAD-PERSYST-UPR Systèmes bananes et ananas (MTQ) ORCID: 0000-0001-5484-1970
• Lavigne Anaïs
• Mollot Grégory
• Vinatier Fabrice, CIRAD-PERSYST-UPR Systèmes bananes et ananas (MTQ)
• Achard Raphaël, CIRAD-PERSYST-UPR Systèmes bananes et ananas (MTQ)
• Okolle Justin, CARBAP (CMR)
• Tixier Philippe, CIRAD-PERSYST-UPR Systèmes bananes et ananas (MTQ) ORCID: 0000-0001-5147-9777

Source : Cirad - Agritrop (https://agritrop.cirad.fr/558150/)

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