Portail HAL Institut Agro Montpellier
Not a member yet
54878 research outputs found
Sort by
Bisexual releases are as effective as male‐only releases to control <i>Drosophila suzukii</i> with the sterile insect technique
No full textInternational audienceBACKGROUND: The sterile insect technique (SIT) suppresses insect reproduction by repeatedly releasing sterile insects and allowing them to mate with insects of the same species in the wild. While the classical SIT relies on sterile males mating with wild females, there is a debate regarding the risks and benefits of releasing sterile females along with the sterile males (i.e. bisexual releases). In a replicated cage experiment, we compared the effect of unisexual and bisexual sterile releases of Drosophila suzukii on induced sterility. To ensure field-realism, fertile females -wild-F0 freshly emerged from field-collected sweetcherries -were placed in cages with artificial vegetation and plastic berries.RESULTS: The proportion of fertile females that produced offspring was not significantly different in unisexual and bisexual treatment (45% and 46%, respectively). Excluding females that had not mated (i.e. no sperm in the spermathecae) from the analysis had no influence.CONCLUSION: These results suggest the release of sterile females does not always affect the efficacy of the SIT. Even though additional phenomena may arise when scaling up from cages to the field, we conclude that sorting females with genetic constructs or robotic systems is probably dispensable in D. suzukii SIT, at least when deployed in confined farming systems.</div
Chemical composition and aphicidal activity of Santolina africana essential oil: a new opportunity in Aphis gossypii management?
No full textData availability statement: All sequences that confirm the molecular identity of the studied material are available on GenBank under the Accession numbers indicated in the text (PV738052-PV738059). All DNA extracts are stored at the Centre de Biologie pour Gestion des Populations (CBGP), Montferrier sur Lez (France) under the authority of Nathalie Gauthier. All phytochemical profiles and aphicidal results are stored at the Universite Djillali Liabes, Sidi Bel Abbes (Algeria) under the authority of Radouane Zaid.International audienceThe cotton aphid (Aphis gossypii), is a polyphagous species that transmits phytoviruses. It is one of the most damaging and widespread insect pests in pomegranate orchards worldwide, including countries of the Mediterranean basin such as Algeria. The control of its populations mainly relies on synthetic pesticides although safer alternatives, such as botanical insecticides, warrant further exploration. This study investigated the aphicidal potential of the essential oil (EO) of Santolina africana leaves (Asteraceae), widespread North African shrub, against A. gossypii populations under laboratory conditions. The EO phytochemical profile was determined by GC/MS. The 49 compounds identified were mainly oxygenated sesquiterpenes and monoterpenes, with artemisia ketone (22.69%) and longiverbenone (16.55%) as the dominant compounds. The toxicity of the EO was tested at five concentrations (0.1–1.6%, v/v) through topical contact and fumigation bioassays across seven exposure times (2–72 h). Each bioassay involved a population of 25 aphids with five replicates, totalling 750 individuals per method. Mortality was both concentration- and time-dependent, reaching 100% within 12 h under fumigation. After 24 h, fumigation required EO concentrations 3.6 and 36 times lower than topical application to achieve LC₅₀ and LC₉₀ values, respectively. This study provides the first evidence of the strong biocidal activity of S. africana leaf EO against A. gossypii populations, highlighting its potential for pest populations and for reducing the spread of the phytoviruses transmitted by this aphid
Synthèse des connaissances sur les fourmis (Hymenoptera, Formicidae) du Parc national des Écrins (SE France)
No full textInternational audienceSynthesis of knowledge on the ants (Hymenoptera, Formicidae) of the Écrins national park (SE France). The synthesis of 1686 occurrence data of ants (family Formicidae, Hymenoptera) identified to the species level, distributed across the entire Écrins National Park (core zone and adhesion zone) revealed 83 species, i.e. more than one third of the myrmecofauna of metropolitan France. The species ac- cumulation curve shows, however, that the completeness of the inventory is moderate. Although the first data date back to 1984, more than 90% of the data have been obtained since 2018. To remedy to the knowledge deficit, the park adopted a strategy in 2018 which consisted in: first mobilizing park agents for opportunistic collections throughout the territory and an association of ant specialists for identification, and second occasionally involving ant specialists in field surveys. This sampling effort allowed exploring the distribution of diversity and species according to the type of environment and to elevation, and to reveal the presence of species that could represent an issue for the park. In particular, Formica paralugubris Seifert, 1996, a species of redwood ant endemic to the western Alps and the Jura, very little known in France, was detected in several sites. This species being difficult to distinguish from Formica lugubris Zetterstedt, 1838 – a very common boreomontane species – the identification was based on a double diagnosis: morphological and molecular. The inventory revealed other remarkable species such as Leptothorax gredleri Mayr, 1855, a species from central and northern Europe whose only known station in France is the one in the park, and Leptothorax pacis (Kutter, 1945), a very rare species occurring mainly in the Alps and the Pyrenees. A conservation value analysis relying on a method specific to the park revealed Formica paralugubris as a species with a particularly high conservation value within the territory of the park.La synthèse de 1686 données d’occurrence de fourmis (famille des Formicidae, Hymenoptera) identifiées à l’espèce réparties sur l’ensemble du parc national des Écrins (zone cœur et zone d’adhésion) a permis de recenser 83 espèces, soit plus du tiers de la myrmécofaune de France métropolitaine. La courbe d’accumulation des espèces montre cependant que la complétude de l’inventaire des espèces est modérée. Bien que les premières données datent de 1984, plus de 90 % des données ont été obtenues depuis 2018. Face au déficit de connaissance d’avant 2018, la stratégie du parc, qui s’est avérée efficace, a d’abord été de mobiliser les agents du parc pour des collectes opportunistes sur l’ensemble du territoire et une association spécialiste des fourmis pour l’identification, puis de faire intervenir ponctuellement des spécialistes sur le terrain. Cette pression d’échantillonnage a permis d’explorer la distribution de la diversité et des espèces en fonction du type de milieu et de l’altitude, et de révéler la présence d’espèces pouvant constituer un enjeu pour le parc. En particulier, Formica paralugubris Seifert, 1996, une espèce de fourmis rousse des bois endémique de l’ouest des Alpes et du Jura, très peu connue en France, a été détectée dans plusieurs stations. Cette espèce étant difficile à distinguer de Formica lugubris Zetterstedt, 1838, une espèce boréo-montagnarde très commune, l’identification a porté sur un double diagnostic, morphologique et moléculaire. L’inventaire a révélé d’autres espèces remarquables telles que Leptothorax gredleri Mayr, 1855, une espèce d’Europe centrale et du nord dont la seule station connue en France est celle du parc, et Leptothorax pacis (Kutter, 1945), une espèce très rare présente essentiellement dans les Alpes et les Pyrénées. L’évaluation de patrimonialité selon une méthode propre au parc n’a révélé qu’une seule espèce à considérer comme patrimoniale pour le parc : Formica paralugubris
2D numerical model for gas mass transfers in modified atmosphere packaging systems
No full textInternational audienceThe complexity of some food-packaging systems requires mathematical models of mass transfers to accurately predict the evolution of headspace gas composition during storage and better anticipate food shelf-life. In this study, a numerical 2D model of O 2 /CO 2 transfer in a cheese packaging system was proposed. The results showed significant involvement of gas sorption/desorption in food and permeation through the tray in evolution of gases in headspace. In this context, only a 2D model provided a good fit to experimental results, as gas permeation at the food/tray interface was non-negligible, limiting 1D approaches. This validated 2D model was then used in a global sensitivity analysis employing the Morris method to quantitatively identify the most influential mass transfer parameters affecting prediction accuracy. The results revealed a significant impact of O 2 and CO 2 permeability of the tray and their activation energies, as well as O 2 and CO 2 solubility and diffusivities in food. Therefore, to obtain a robust model of a food packaging system, it is recommended to integrate gas transfers between food and tray when the food-tray interface area is significant (2D model) and to precisely evaluate the gas permeability of the tray. These transfers can be neglected when this interface area is minimal (1D model).</div
Camel meat composition by species, breeds, publication year, age, and breeding system: A global systematic review and meta-analysis
No full textInternational audienceCamel meat is increasingly being recognized as a sustainable and nutritious red meat source, particularly in arid and semi-arid areas where camels are thriving. However, its chemical composition and sensory attributes vary significantly owing to genetic, management, and environmental factors. This study conducted a systematic re-view and a meta-analysis to quantify the nutritional and sensory properties of camel meat and identify the key factors influencing these characteristics. A systematic review of peer-reviewed studies was conducted using Springer, PubMed/MEDLINE, Scopus, and ScienceDirect databases. This review comprised 57 papers publishedin English from 12 countries, covering the period between January 1991 and August 2024, including 377 analyses focusing on camel species, breeds, and breeding systems. Statistical analyses were performed to determine the effect sizes, heterogeneity, and impact of the moderating factors. The findings from our meta-regression andsubgroup analyses revealed that variations in camel meat profiles are influenced by multiple factors, including breeding system, camel species, breeds, and age, but not by sex. Subgroup analysis revealed that higher final body weight (FBW) was reported for meat from Camelus bactrianus camels raised under the extensive system.Camels slaughtered at ≤6 years of age were characterized by higher dry matter, ash, and fat contents, but lower sarcomere length, lightness, redness, and cobalt content. The Najdi, Baladi Saudi, and Pakistani breeds were characterized as tender meat breeds. This study emphasizes the need for improved breeding strategies, meatprocessing techniques, and market awareness to enhance the appeal of camel meat. These findings provide valuable insights for livestock producers, policymakers, and the food industry, supporting the promotion of camel meat as a viable substitute for traditional red meat in regions affected by climate change and food insecurity
Quel avenir pour les politiques publiques en faveur de la démocratie alimentaire ?
No full textConclusionNational audienc
Flash vacuum expansion technology for small-scale production of fruit puree: development and quality assessment
No full textInternational audienceFruit processing at small scale often lacks access to efficient, integrated technologies capable of ensuring product quality and safety. Flash Vacuum Expansion emerges as a promising alternative to conventional thermal treatments by coupling rapid steam heating with instant decompression, enabling simultaneous pasteurization and cooling, tissue disintegration, and deaeration. This study presents the design, construction, and validation of an optimized Flash Vacuum Expansion prototype tailored for small- and medium-scale agroindustries. The system integrates six unit operations—blanching, pasteurization, mashing, cooling, deaeration, and pulping—of which the last four are conducted under vacuum conditions. Heating is achieved through a screw conveyor blancher equipped with direct steam injection, while the vacuum operations are synchronized using double-valve airlocks. Performance was assessed using açai and Andean blackberry, evaluating microbial inactivation, physicochemical and rheological properties, and energy efficiency. FVE-treated purees showed complete microbial inactivation (<10 CFU/g), significant increases in pulp yield and extraction efficiency, reduced insoluble solids, enhanced pigment release, and superior rheological consistency. Energy consumption analysis revealed specific energy consumption (SEC) values as low as 0.97 MJ/kg—markedly lower than conventional processing benchmarks. The proposed FVE system represents a scalable and energy-efficient solution for producing high-quality fruit purees
Ten assertions on einkorn from a participatory living-lab: right or false?
No full textInternational audienceHighlights: • French farmers grow very few varieties of einkorn, whereas there is a huge diversity in the einkorn species! • Einkorn yield is very few mentioned as a criterion farmers are interested in. • Einkorn may be adapted to a large range of environments but the current varieties are not well adapted to agroforestry. • Einkorn is not adapted to celiac patients and seems no more digestible than durum wheat with in vitro experiments. • Einkorn, considered a minor cereal, is of major economic interest.Abstract: A participatory living-lab, implemented in Occitania region (south of France), is clustering farmers, processors, chefs, researchers, teachers, students and citizens, interested by einkorn (Triticum monococcum subsp. monococcum). During meetings, field days, open laboratories days, farms or mills visits, several assertions were collected and the ten most commonly cited were selected. For each assertion, experiments were set up and the results were compared with the scientific literature in order to discuss, confirm or refute them. We concluded by right or false for each assertion: “French farmers grow very few varieties of einkorn”: right, “There is no genetic diversity in the einkorn species”: false, “Yield is the only trait farmers are interested in”: false, “The einkorn is only adapted to very specific environmental conditions”: false, ““IGP haute Provence” is the best adapted to our Living Lab cropping conditions”: false, “Einkorn is not adapted to agroforestry”: right, with the current varieties, “Einkorn is of great benefit to celiac patients”: false, “Einkorn is more digestible than durum wheat”: false, ““IGP Haute Provence” is the variety of einkorn that makes the best pasta”: false, “Einkorn is less profitable than wheat because of its low yield”: false . The participatory einkorn breeding program being implemented will allow to meet the constraints and requirements of all stakeholders
Legal Repair: Domesticating European Legislation on Pig Welfare
No full textInternational audienceOur daily activities rely on a proliferating number of things that are subject to decay. As stressed in a growing body of literature, repair is critical to the smooth functioning of material infrastructure. However, this scholarship has overlooked a crucial dimension: things become fragile not only due to material degradation but also as a result of regulatory change. This article introduces the notion of “legal repair” to describe how, in the face of legal change, certain actors reassemble the material world. We elaborate on this concept through an analysis of the domestication of European Union (EU) animal welfare legislation by the French pig sector. While it was feared that stricter pig housing standards would fragilize the existing farms, pig farmers complied using technical systems that failed to significantly improve animal welfare. We analyze this domestication of EU legislation as a process of legal repair. Alongside the political work of the leaders of the pig sector, agricultural advisers also played a key role. Their work reveals the relational nature of legal repair: in the production of “local specifications” matching the demands of existing farming systems, in the negotiation of the finer points of the legislation, and in the redefinition of farming performance
Comportement quasi-limite du processus de branchement bi-sexué multi-type de Galton-Watson sous-critique
No full textInternational audienceWe investigate the quasi-limiting behaviour of bisexual subcritical Galton-Watson branching processes. While classical subcritical Galton-Watson processes have been extensively analyzed, bisexual Galton-Watson branching processes present unique difficulties because of the lack of the branching property. To prove the existence of and convergence to one or several quasi-stationary distributions, we leverage on recent developments linking bisexual Galton-Watson branching processes extinction to the eigenvalue of a concave operator