Biological regulations of Cosmopolites sordidus in the food web of banana agroecosystems
type: Dataset
description: In agroecosystems, food webs are often structured from the crop, which enables the associated herbivores, including pests, to develop. For instance, monoculture in banana fields allowed the development of the banana weevil (Cosmopolites sordidus) populations. Borrowing larvae of C. sordidus cause banana plants topple over, which dampens the yield in most production areas. In this Ph.D. thesis, we attempted to disclose the structure and function of the banana food web, and particularly the trophic interactions that link banana weevil to others species. The applied perspective was to enhance population of generalist predators in order to increase the natural regulation of the pest.1. What is the effect of adding a cover crop on the predation of the pest?By using a variety of methods - stable isotopes analyses, trapping, artificial infestation of banana trees, we successfully tested the hypothesis according to which the addition of a cover crop, by enabling population of alternative preys to develop in the system, induces a change in predator diet, an increase of predator densities, and a greater predation rate on the eggs of C. sordidus.2. How is structured the food web?We combined next generation sequencing (454 technology) with the DNA barcoding concept to identify prey into gut contents of consumers. We used a chloroplastic marker (trnL) to identify the diet of herbivores, and a mitochondrial marker (CO1) for predators. This approach enabled the detection of unexpected species, the identification of the natural enemies of the pest, and the weighting of trophic interactions at the population scale.3. How can food web structure influence pest regulation?We searched structural elements (network motifs) occurring in the food webs of two banana agroecosystems (on bare soil and with cover crop), and we inferred the system functions. We detected the “bi-fan” size-4 motif, which occurred more frequently in the cover cropped food web than in random food webs. Interestingly,…
landing page: https://theses.hal.science/tel-00932464
identifier: NNT: 2012AVIG0642
keyword: dna-metabarcoding
keyword: generalists-predators
keyword: infoeu-reposemanticsdoctoralthesis
keyword: isotope-stable
keyword: metabarcoding-adn
keyword: motifs-de-reseau
keyword: network-motifs
keyword: pest-regulation
keyword: predateurs-generalistes
keyword: predation-rate
keyword: regulation
keyword: sdvsalife-sciences-q-bioagricultural-sciences
keyword: stable-isotopes
keyword: taux-de-predation
keyword: theses
issued: 2026-05-07T09:11:12.885865
modified: 2026-05-07T09:11:12.885869
language: fr
contact point: Organization
  fn: CCSD

test_moissonnage_selune
type: Agent

Biological regulations of Cosmopolites sordidus in the food web of banana agroecosystems
type: Distribution
format: HTML
access URL: https://theses.hal.science/tel-00932464
issued: 2026-05-07T09:11:12.895605
modified: 2026-05-07T09:11:12.867186