A multi-approach improves the description of the entomopathogenic nematodes distribution in corn fields

• Main Authors: Depuydt, Elisabeth, Ogier, Jean-Claude, Cabre, Lisa, Ali, Nusrat, Mahieu, Patrice, Villenave, Cécile, Nguema-Ona, Eric, Gaudriault, Sophie
• Other Authors: Centre Mondial de l'Innovation Roullier, Groupe Roullier, Diversité, Génomes & Interactions Microorganismes - Insectes Montpellier (DGIMI), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université de Montpellier (UM), Chambre Régionale d'Agriculture de Midi Pyrénées, Chambre Régionale d'Agriculture d'Occitanie (CRA Occitanie), Elisol Environnement, International Organisation for Biological and Integrated Control
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2023
• Subjects: Entomopathogenic nematode; agricultural soil; biological control; conservation; molecular detection; [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology; [SDV]Life Sciences [q-bio]; Antarc*; Antarctica
• Online Access: https://hal.inrae.fr/hal-04129939; https://hal.inrae.fr/hal-04129939/document; https://hal.inrae.fr/hal-04129939/file/Poster%20Elisabeth%20Depuydt.pdf

International audience Entomopathogenic nematodes (EPNs), Steinernema sp. and Heterorhabditis sp., are soil-dwelling insect parasites distributed in all continents except in Antarctica. Moreover, the detection method may bias the diagnosis of the presence of EPNs in soils. The classical method for the detection of EPNs is the baiting method by Galleria mellonella. The objective of this study is to combine several methods to improve the detection of EPNs in cultivated soils. We assumed that a multi-approach which combines baiting with successive trapping cycles (Abd-Elgawad, 2020, Nematology) and molecular detection (Campos-Herrera et al., 2011, Annals of Applied Biology) would provide the most accurate picture of the presence and diversity of EPNs in the sampled soils. Map of the 43 sampling plots cultivated in corn in South Western France EPNs detection by successive trapping cyles (28%) Three species were isolated: S. carpocapsae, S. feltiae and H. bacteriophora. The multiplication of the baiting cycles allowed to increase the number of positive plots and the species diversity of EPNs isolated Steinernema sp. detection by ddPCR (33%) ❖ Mismatches are observed between the detection methods (e.g. molecular detection of EPNs in negative plots by baiting). ❖ Using of multi-approach improves the detection of native EPNs in soils. ❖ A good picture of the distribution of EPNs in agricultural soils is useful for their use in biological control by conservation.