Assessing the role of non-cotton refuges in delaying Helicoverpa armigera resistance to Bt cotton in West Africa

Brévault Thierry, Nibouche Samuel, Achaleke Joseph, Carrière Yves. 2012. Assessing the role of non-cotton refuges in delaying Helicoverpa armigera resistance to Bt cotton in West Africa. Evolutionary Applications, 5 (1) : 53-65.

https://doi.org/10.1111/j.1752-4571.2011.00207.x

Article de revue ; Article de revue à facteur d'impact Revue en libre accès total

Version publiée - Anglais
Utilisation soumise à autorisation de l'auteur ou du Cirad.
document_563337.pdf
Télécharger (381kB)

Url - jeu de données - Entrepôt autre : https://doi.org/10.5061/dryad.ts7sm

Quartile : Q2, Sujet : EVOLUTIONARY BIOLOGY

Résumé : Non-cotton host plants without Bacillus thuringiensis (Bt) toxins can provide refuges that delay resistance to Bt cotton in polyphagous insect pests. It has proven difficult, however, to determine the effective contribution of such refuges and their role in delaying resistance evolution. Here, we used biogeochemical markers to quantify movement of Helicoverpa armigera moths from non-cotton hosts to cotton fields in three agricultural landscapes of the West African cotton belt (Cameroon) where Bt cotton was absent. We show that the contribution of non-cotton hosts as a source of moths was spatially and temporally variable, but at least equivalent to a 7.5% sprayed refuge of non-Bt cotton. Simulation models incorporating H. armigera biological parameters, however, indicate that planting non-Bt cotton refuges may be needed to significantly delay resistance to cotton producing the toxins Cry1Ac and Cry2Ab. Specifically, when the concentration of one toxin (here Cry1Ac) declined seasonally, resistance to Bt cotton often occurred rapidly in simulations where refuges of non-Bt cotton were rare and resistance to Cry2Ab was non-recessive, because resistance was essentially driven by one toxin (here Cry2Ab). The use of biogeochemical markers to quantify insect movement can provide a valuable tool to evaluate the role of non-cotton refuges in delaying the evolution of H. armigera resistance to Bt cotton.

Mots-clés Agrovoc : Gossypium, plante hôte, Helicoverpa armigera, résistance aux organismes nuisibles

Mots-clés géographiques Agrovoc : Afrique occidentale, Cameroun

Classification Agris : H10 - Ravageurs des plantes
F30 - Génétique et amélioration des plantes

Champ stratégique Cirad : Axe 1 (2005-2013) - Intensification écologique

Auteurs et affiliations