Cover Cropping Alters the Diet of Arthropods in a Banana Plantation: A Metabarcoding Approach

Grégory Mollot (1) , Pierre-François Duyck (2) , Pierre Lefeuvre (2) , Francoise Lescourret (1) , Jean-François Martin (3) , Sylvain Piry (4) , Elsa Canard (5) , Philippe Tixier (6, 7)

1 PSH - Unité de recherche Plantes et Systèmes de Culture Horticoles
2 UMR PVBMT - Peuplements végétaux et bioagresseurs en milieu tropical
3 Montpellier SupAgro - Centre international d'études supérieures en sciences agronomiques
4 UMR CBGP - Centre de Biologie pour la Gestion des Populations
5 MIVEGEC - Maladies infectieuses et vecteurs : écologie, génétique, évolution et contrôle
6 Departamento de Agricultura y Agroforesteria
7 UPR 26 Systèmes bananes et ananas - Systèmes de Cultures Bananes, Ananas, et Plantains

Plant diversification using cover crops may promote natural regulation of agricultural pests by supporting alternative prey that enable the increase of arthropod predator densities. However, the changes in the specific composition of predator diet induced by cover cropping are poorly understood. Here, we hypothesized that the cover crop can significantly alter the diet of predators in agroecosystems. The cover crop Brachiaria decumbens is increasingly used in banana plantations to control weeds and improve physical soil properties. In this paper, we used a DNA metabarcoding approach for the molecular analysis of the gut contents of predators (based on mini-COI) to identify 1) the DNA sequences of their prey, 2) the predators of Cosmopolites sordidus (a major pest of banana crops), and 3) the difference in the specific composition of predator diets between a bare soil plot (BSP) and a cover cropped plot (CCP) in a banana plantation. The earwig Euborellia caraibea, the carpenter ant Camponotus sexguttatus, and the fire ant Solenopsis geminata were found to contain C. sordidus DNA at frequencies ranging from 1 to 7%. While the frequencies of predators positive for C. sordidus DNA did not significantly differ between BSP and CCP, the frequency at which E. caraibea was positive for Diptera was 26% in BSP and 80% in CCP; the frequency at which C. sexguttatus was positive for Jalysus spinosus was 14% in BSP and 0% in CCP; and the frequency at which S. geminata was positive for Polytus mellerborgi was 21% in BSP and 3% in CCP. E. caraibea, C. sexguttatus and S. geminata were identified as possible biological agents for the regulation of C. sordidus. The detection of the diet changes of these predators when a cover crop is planted indicates the possible negative effects on pest regulation if predators switch to forage on alternative prey.

Mots clés: cosmopolites-sordidus germar; structured food webs; stable-isotopes; body-size; predators; natural enemies; trophic position; species abundance; ecological community description; dna

Domaines: Sciences agricoles; Biologie animale; Biologie du développement; Biodiversité et Ecologie

Grégory Mollot, Pierre-François Duyck, Pierre Lefeuvre, Francoise Lescourret, Jean-François Martin, et al.. Cover Cropping Alters the Diet of Arthropods in a Banana Plantation: A Metabarcoding Approach. PLoS ONE, 2014, 9 (4), ⟨10.1371/journal.pone.0093740⟩. ⟨hal-01189949⟩