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DGIMI est une unité mixte de recherche ayant pour tutelles INRAE et l'Université de Montpellier. Elle est située sur le campus Triolet de l'Université de Montpellier et accueille une trentaine de personnels INRAE et UM.

Les recherches développées dans l'UMR DGIMI visent à mieux comprendre les interactions entre les insectes et leur environnement biotique et abiotique dans les agrosystèmes, selon deux axes thématiques 

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HAL : Dernières publications

  • [hal-05734157] Exploratory study to identify factors affecting the presence of genus Steinernema entomopathogenic nematodes in maize fields in South-West France

    Entomopathogenic nematodes (EPNs) are soil-dwelling parasites with a large range of insect hosts. They are valuable components of biological control products against insect pests (in greenhouses, for example) but their large-scale use in field crops is often limited by prohibitive costs, poor persistence, and low efficacy in non-native soils. The use of EPNs in conservation biological control — the use of different agricultural practices to promote the presence of native EPNs in field soils — has recently been proposed. Expanding our previous research mapping the occurrence of Steinernema spp. in maize fields in South-West France, this study explores different methodological approaches for investigating the biotic and abiotic factors associated with Steinernema presence, including soil properties, agricultural practices, and soil nematofauna characteristics. We hypothesised that Steinernema spp. occurrence is primarily driven by soil abiotic properties, agricultural management practices affecting habitat disturbance, and soil nematofauna characteristics, and is further influenced by plant diversity through crop rotations and cover crops. We performed univariate (Spearman’s correlation analysis and Chi2 tests) and multivariate (ANOVA) analyses on 46 explanatory variables obtained from 41 maize plots. We also tested a generalized linear model (GLM). For this last approach, given the large number of explanatory variables relative to the number of plots, we conducted a preliminary selection procedure and reduced the number of variables to four: mean weight diameter (MWD), CaO content, main crop alternation and the diversity of plant species used as cover crops. The various approaches converged to identify maize monoculture over five years as the strongest potential explanatory variable for the presence of Steinernema. These results suggest that, in the maize fields of South-West France, EPNs require a certain stability of the vegetation covering agricultural soils. These findings require confirmation in future studies with additional datasets obtained in other agronomic and pedoclimatic contexts.

    ano.nymous@ccsd.cnrs.fr.invalid (Elisabeth Depuydt) 01 Sep 2026

    https://hal.science/hal-05734157v1
  • [hal-05727261] Differences in mainland–island genetic diversity in two moths suggest species-specific outcomes

    Genetic divergence along elevational gradients between mainland and island populations provides an opportunity to test the island genetic erosion model, which predicts reduced genetic diversity and increased differentiation in island populations. We examined two moth species, a geometrid moth ( Alcis angulifera ) and an erebid moth ( Hydrillodes morosa ), sampled along elevational gradients on Mt. Jirisan (mainland) and Mt. Hallasan (island) in southern South Korea. A total of 155 individuals were analyzed using mitochondrial cytochrome oxidase subunit I (mt COI) sequences. We identified 61 haplotypes across both species. A. angulifera exhibited similarly high genetic diversity on the mainland and island, whereas H. morosa showed overall lower diversity relative to A. angulifera but pronounced regional differences, with significantly higher haplotype and nucleotide diversity on the island. Mantel tests revealed significant genetic divergence between mainland and island populations but not within individual mountains, suggesting ongoing gene flow within elevational gradients. AMOVA indicated moderate differentiation in A. angulifera (F CT = 0.08) and stronger differentiation in H. morosa (F CT = 0.14), with most genetic variation occurring within populations. Gene flow estimates further highlighted contrasting patterns, with high connectivity in A. angulifera (Nm = 5.49) and restricted migration in H. morosa (Nm = 0.08). Together, these results indicate that while A. angulifera maintains genetic cohesion across regions, H. morosa exhibits stronger geographic and elevational structuring due to limited gene flow. Our findings do not support a universal reduction in genetic diversity in island populations; instead, they highlight the importance of species-specific ecological traits and geographic context in shaping genetic diversity patterns, suggesting that the island genetic-erosion pattern is more context-dependent than previously appreciated.

    ano.nymous@ccsd.cnrs.fr.invalid (Sei-Woong Choi) 26 Aug 2026

    https://hal.science/hal-05727261v1
  • [hal-05669785] Investigating the Genetic Underpinnings of Ongoing Fall Armyworm ( FAW ) Range Expansion in Aotearoa New Zealand

    Spodoptera frugiperda (fall armyworm; FAW) is a major agricultural pest native to the Americas, with the first reported invasion of Africa in early 2016. Since then, FAW has spread rapidly across Africa and Asia before invading Australia (2020) and first being detected in Aotearoa New Zealand in February 2022. Here, we assessed the whole genomes of 34 novel FAW individuals along the invasion front (representing three new invasive populations from Cambodia, Australia, and New Zealand) with the largest publicly available global FAW genome dataset ( n = 173), resulting in a dataset of 112 and 99 samples from the invasive and native range, respectively, to: (1) place the new invasive populations within the global invasion; (2) identify the potential geographic origin of the New Zealand invasion, including from a single or multiple incursion event; and (3) assess pre‐existing insecticide resistance potential at the invasion front. We confirm that these new invasions conform to the broad population structure of the initial invasive populations identified in Benin (West Africa), all of which belong to the invasive corn strain, as defined through previous triosephosphate isomerase (TPI) analysis and associated isolation from specific host plants. While we could not confidently assign the source population of the New Zealand invasion, we find preliminary support for a multiple introduction hypothesis in our data, which could contribute to increased genetic diversity within the New Zealand population. Further sampling is therefore required to fully characterise the origins of the New Zealand invasion. In novel samples, we detected putative insecticide resistance alleles previously reported in other invasive populations. These resistant loci should be tracked over time to understand the mechanisms enabling the invasion success of FAW in the Asia‐Pacific region. We emphasise that sharing of genomic resources between institutions and consortia is an essential first step in the control of this global invader.

    ano.nymous@ccsd.cnrs.fr.invalid (Amy Vaughan) 25 Jun 2026

    https://hal.science/hal-05669785v1

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article

31 juillet 2026

Rédaction : A-N. Volkoff, S. Gaudriault, A-S Gosselin-Grenet, I. Seninet

« RAVAGÉS »

« Une conférence théâtralisée pour sauver ta culture »
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Candidatez aux sujets de thèse 2026

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Dans le cadre du concours doctoral 2026 de l’école doctorale GAIA, DGIMI propose plusieurs sujets de thèse. N’hésitez pas à contacter les encadrants si vous souhaitez candidater.

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2 sujets de thèse à pourvoir

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Dans le cadre du projet interdisciplinaire microbiologie/chimie "MetaboNEP: Exploration métabolomique et fonctionnelle des bactéries associées aux nématodes entomopathogènes: vers de nouveaux métabolites pour le biocontrôle et l’écologie microbienne", sont proposés à l'université de Montpellier (collaboration DGIMI/IBMM).

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On recrute un.e chercheur.se

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Nous recherchons tout particulièrement à renforcer notre expertise sur le rôle des éléments transposables (ET) ou des éléments viraux endogènes (EVE) dans l’évolution et l’adaptation des génomes d’insectes.