Cover cropping alters the diet of arthropods in a banana plantation: a metabarcoding approach.
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.
CIRAD, UR 26 Systèmes de culture à base de bananiers, plantains et ananas, PRAM, Le Lamentin, Martinique, France; INRA, UR-1115 Plantes et Systèmes de culture Horticoles, Avignon, France.
Gregory
G
Mollot
CIRAD, UR 26 Systèmes de culture à base de bananiers, plantains et ananas, PRAM, Le Lamentin, Martinique, France; CIRAD, UMR PVBMT, CIRAD/Université de La Réunion, Pôle de Protection des Plantes, Saint-Pierre, La Réunion, France.
Pierre-François
PF
Duyck
CIRAD, UMR PVBMT, CIRAD/Université de La Réunion, Pôle de Protection des Plantes, Saint-Pierre, La Réunion, France.
Pierre
P
Lefeuvre
INRA, UR-1115 Plantes et Systèmes de culture Horticoles, Avignon, France.
Françoise
F
Lescourret
Montpellier-SupAgro, UMR CBGP, Montferrier-sur-Lez, France.
Jean-François
JF
Martin
INRA, UMR1062 CBGP, Montferrier-sur-Lez, France.
Sylvain
S
Piry
CIRAD, UR 26 Systèmes de culture à base de bananiers, plantains et ananas, PRAM, Le Lamentin, Martinique, France; CNRS-IRD, UMR 2724 MIVEGEC, Montpellier, France.
Elsa
E
Canard
CIRAD, UR 26 Systèmes de culture à base de bananiers, plantains et ananas, PRAM, Le Lamentin, Martinique, France; CIRAD - CATIE, Departamento de Agricultura y Agroforesteria, CATIE, Turrialba, Costa Rica.
Philippe
P
Tixier
D000818:Animals; D018556:Crops, Agricultural; D004032:Diet; D007300:Insect Control / Q000379:methods*; D007313:Insecta / Q000502:physiology*; D028521:Musa; D010572:Pest Control, Biological / Q000379:methods*; D011235:Predatory Behavior / Q000502:physiology*