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International audience; Strategic decisions condition the orientation and associated agricultural practices of farms for many years, especially in fruit production where trees are planted for ten to fifteen years. However, this type of decision is rarely addressed in decision support approaches. An approach was developed to support strategic thinking in fruit tree farms through the use of a simulation tool called CoHort and built in Excel. CoHort evaluates the impacts of a given set of practices on the economic performances (gross and net margins), labour organization and phytosanitary performances (Treatment Frequency Index) of fruit tree farms. It has been built with cooperatives technicians and used with apple farmers in a partic-ipatory process to integrate the needs and objectives of the farmers and technicians. The approach alternates between simulations with the tool and discussions with the farmer. It is illustrated for two apple farmers in France aiming to reduce their pesticide use. The first farmer wanted to convert five hectares out of eight to organic production. Simulations showed that the raw margin was increased by 259%, the Treatment Frequency Index was reduced of 26%, but the labour demand was 9% higher. The second farmer wanted to replace 1.5 hectares out of 15 ha with a new scab-resistant cultivar. Results showed that the average TFI at the farm scale was decreased by 17%, the labour demand was similar, and the raw margin increased by 5%. Based on simulation outputs apple farmers could estimate the possible impacts of their projects to their farm. The tool flexibility allows using it with different farm structures and projects.

International audience; The first tools to assess agri-chains focused on their economic aspects. Following requests from professionals from different agri-chains, CIRAD undertakes original research to develop methods for the environmental and social assessment of agri-chains. Indeed, although the production of food consumes resources and causes pollution, thus leading to various types of externalities, it remains an essential activity. It also generates positive or adverse social effects. Even though some large multinational companies wish to reduce their environmental impacts or improve their social impact, their desire or willingness is not sufficient. It is necessary to evaluate the environmental and social consequences of their actions in the most relevant manner possible. This chapter focuses on life cycle assessment methods because they are suitable for a chain-based reasoning and, due to their design, are the only methods that take the transfer of impacts into account. Since the pollution emitted by an agri-chain (or areas of consumption of non-renewable resources) can be spread out over several sites, the life cycle assessment method replaces the direct measurement of emissions. These are indirect assessment methods based on benchmarks stored in databases. Several configurations are possible in order to define boundaries (at least the spatial and temporal boundaries, but also that of affected actors in the case of a social life cycle assessment) of the system that will be studied by this type of analysis. The extent of change (marginal or extensive which modifies the system’s structure itself) also influences the determination of the system’s boundaries. The variety and sophistication of tools available for this type of assessment reflects the strong and ever increasing societal demand. The assessment addresses four key requirements: strengthening one’s market power, adjusting one’s action plan, acquiring knowledge in order to decide, and the need for self-assurance.

BGPI : équipe 2; The split GFP technique is based on the spontaneous auto-assembling of two non-fluorescent GFP fragments, GFP1-10 (residues 1-214, the detector) and GFP11 (residues 214-233, the tag) to reconstitute a fluorescent GFP (Cabantous et al., 2005). Its primary use is tracking proteins in vivo when for various reasons the whole GFP molecule can not be fused to the protein of interest. We used here the split GFP technique to to contribute to the characterisation of molecular and cellular details of CaMV infection. GFP11 was fused to the N-termini of proteins P2 or P6 of Cauliflower mosaic virus (CaMV) strain B-JI. We chose the virus factory matrix protein P6, because it is the first viral protein to be translated during infection and thus suited to study early infection events, and P2 because it is the aphid transmission factor, and transmission a focus of our research. Infectious plasmids were used for mechanical inoculation of transgenic Arabidopsis thaliana Col0 plants expressing GFP1-10 constitutively with the 35S promoter (Sakalis et al., 2014). We obtained infected plants showing typical symptoms and displaying fluorescent virus factories (CaMV-P6-GFP11) or transmission bodies (CaMV-P2-GFP11). Both mutants were stable after several passages, but symptoms were delayed We are presently characterizing B-JI-GFP11-P6 for its suitability as a tool to study virus inoculation and other infection steps. Virus accumulation was verified by Western blotting, where a similar expression of proteins P2 and P6 compared to wild type CaMV BJI was confirmed. The virus formed correct transmission bodies and virus factories, and the tag did not interfere with virus infectivity. Transmission tests with the green peach aphid Myzus persicae L. were carried out using Arabidopsis plants infected with pGREEN-BJI-GFP11-P6 as virus source and turnip as receptor plant. Transmission rate was 29% with one aphid/receptor plant, and 83% with 10 aphids/receptor plant. Inmunolabelling of infected Arabidopsis leaves was also performed. The visual monitoring of CaMV infection following inoculation by the vector will be studied. Latest results will be presented.

L'utilisation de pesticides n'est pas sans impact sur l'environnement ni sur la sante humaine. La societe civile mauricienne s'est recemment emparee de la question suite a des detections de pesticides dans des legumes preleves dans les marches de l'ile. Mais quelles sont les marges de manœuvre des producteurs pour faire face a cette demande societale ? Comme les methodes de production etaient jusqu'ici peu documentees, nous avons mene une enquete aupres de 298 producteurs de legumes afin d'analyser leurs pratiques phytosanitaires et d'en evaluer les impacts sur l'environnement. Cette enquete vise a repondre aux questions suivantes : Quels sont reellement les usages de pesticides des producteurs ? Quelles contraintes supportent-ils ? Les producteurs sont plutot âges (60 % ont plus de 50 ans) et peu d'entre eux ont une formation initiale de base. Pres des deux tiers d'entre eux ne sont pas proprietaire du foncier. Dans ces conditions, les producteurs pratiquent une agriculture d'opportunisme visant a optimiser leur parcelle dans le temps et dans l'espace. Aucun risque, aucune perte. La grande majorite des producteurs protegent leurs cultures par des traitements phytosanitaires preventifs contre les nombreux bio-agresseurs recenses. Entre 11 et 53 traitements par an sont ainsi effectues selon les successions culturales entreprises. Pres de 60 insecticides et fongicides sont couramment utilises par les producteurs. L'outil d'aide a la decision « Phyto'Aide » nous a permis d'evaluer, ex ante, le risque du transfert de ces substances vers l'environnement. Ces risques s'averent importants pour tous les pesticides car les bonnes pratiques phytosanitaires sont peu ou pas respectees par les producteurs. Dans ces conditions, de nouvelles strategies de protection contre les bioagresseurs s'averent necessaires. Nous proposons dans cet article differentes pistes d'amelioration, mais aussi une strategie d'accompagnement de ces producteurs pour faire face a une demande societale d'une production saine et sure.

Introduction. Les cultures maraichères occupent une place importante pour l’alimentation humaine et contribuent significativement aux revenus des familles en Afrique de l’Ouest, mais leur production est confrontée à une pression des bioagresseurs qui limite leur productivité. Littérature. Cette revue, basée sur des publications scientifiques, a pour objectif d’évaluer le potentiel des plantes pesticides comme alternative à l’usage des pesticides de synthèse pour lutter contre les bioagresseurs des cultures maraichères en Afrique de l’Ouest. Elle montre que le principal moyen actuel pour combattre ces bioagresseurs repose essentiellement sur les pesticides de synthèse. Cependant, compte tenu de leur nocivité sur l’homme et l’environnement, en plus de la sélection de populations résistantes chez les bioagresseurs, la recherche de solutions alternatives s’impose. Les plantes pesticides se présentent comme une alternative prometteuse dans le contexte ouest-africain. En effet, diverses espèces de plantes pesticides peuvent être utilisées comme extraits de plantes ou en association avec d’autres cultures pour le contrôle des bioagresseurs. Celles-ci sont présentées dans le présent article de synthèse.Conclusions. Les plantes pesticides peuvent être une alternative prometteuse pour la gestion des bioagresseurs des cultures maraichères. Cependant, la plupart d’entre elles ne sont pas cultivées. Explorer les capacités biocides de plantes d’intérêt comme le genre Ocimum, connu pour ses usages thérapeutique, médicinal et alimentaire pourrait être intéressant pour le producteur. Toutefois, les populations doivent être sensibilisées sur les avantages à long terme des produits traités avec les pesticides à base de plantes pour faciliter leur utilisation., Pesticidal plants and vegetable crop protection in West Africa. A reviewIntroduction. Vegetable crops play a leading role in human nutrition and contribute significantly to the incomes of families in West Africa. However, their production is hampered by pressure from pests, which limits their productivity.Literature. This review, based on scientific publications, aims to evaluate the potential of pesticidal plants as an alternative to the use of synthetic pesticides to control vegetable crop pests in West Africa. It shows that the primary current method used to control these pests is mainly based on synthetic pesticides. However, in view of their harmful effects on humans and the environment, in addition to the range of resistant pest populations, the search for alternative approaches is needed. Pesticidal plants are a promising alternative in the West African context. Indeed, various species of pesticidal plant can be used as plant extracts or in association with other crops in pest management. These plants are presented in this review article.Conclusions. Pesticidal plants can be a promising alternative for the pest management of vegetable crops. However, most of these pesticidal plants are uncultivated. Exploring the biocidal capacities of these interesting plants, such as the genus Ocimum, known for its therapeutic, medicinal and food uses, could be of interest for farmers. However, populations need to be made informed of the long-term benefits of products treated with pesticidal plant extract, in order to facilitate their use.

Tomato (Lycopersicon esculentum) is one of the important vegetables in supplying vitamins, min- erals and fiber to human diets worldwide. Its successful production in the tropics is, however, constrained by environmental variations espe- cially under open field conditions. Two trials were conducted at the Horticulture Research and Teaching Field, Egerton University, Kenya to evaluate the effects of agricultural nets (ag- ronets) herein called eco-friendly nets (EFNs) and floating row covers (FRCs) on microclimate modification, yield, and quality of tomato. A ran- domized complete block design with five repli- cations was used. Tomato plants were grown under fine mesh EFN (0.4-mm pore diameter) cover, large mesh EFN (0.9-mm pore diameter) cover or FRC. The EFN and FRC were main- tained either permanently closed or opened thrice a week from 9 am to 3 pm. Two open con- trol treatments were used: unsprayed (untreated control) or sprayed with chemicals (treated con- trol). The use of EFN or FRC modified the micro- climate with higher temperatures, lower diurnal temperature ranges, and higher volumetric wa- ter content recorded compared with the controls. On the other hand, light quantity and photo- synthetic active radiation were reduced by the use of EFN and FRC compared with the controls. The use of FRC and EFN resulted in more fruit and higher percent in marketable yield com- pared with open field production. Fruit quality at harvest was also significantly improved by the use of EFN and FRC. Fruits with higher total soluble solids (TSS), lower titratable acidity (TA), and higher sugar acid ratio were obtained in EFN and FRC treatments compared with the controls. Fruits harvested from EFN and FRC were also firmer compared with control fruits. These find- ings demonstrate the potential of EFN and FRC in modifying microclimate conditions and im- proving yields and quality of tomato under tropi- cal field conditions.

In agroecosystems, the use of biodiversity for natural control of arthropod pests aims to propose an agroecological crop protection, as an alternative to current agrochemical protection. Our study focused on mango agroecosystems in Reunion Island, with the goal of understanding the factors that influence biodiversity and control of arthropod pests. This agroecosystem is characterized by a large diversity (797 arthropod species and 114 plant species) and our results highlight the positive bottom-up and top-down controls of biodiversity in communities. We also highlight the services provided by the dominant species of invasive ants in pest regulation. Two species provide a predation service, and one reduces the diversity of natural enemies of omnivores and appears to explain the negative relationship between omnivore diversity and predation. Finally, we highlight the positive effect of parasitoid diversity and predator diversity on, respectively, the abundance of Seychelles mealybugs and on predation in general. The only significant landscape effect measured in our work is the positive effect of the proportion of mango orchards on the abundance of South African citrus Thrips. These results allow us to identify two factors in the agroecological protection of mango orchards in Reunion: the management of diversified ground cover in orchards; and collective landscape management by limiting the proportion of mango orchards., Dans les agroécosystèmes, l'utilisation de la biodiversité pour la régulation naturelle des arthropodes nuisibles vise à proposer une protection agroécologique des cultures, en alternative à la protection agrochimique actuelle. Notre étude a porté sur les agroécosystèmes à base de manguiers à La Réunion, avec l'objectif de comprendre les facteurs qui influencent la biodiversité et la régulation des arthropodes nuisibles. Cet agroécosystème est caractérisé par une importante diversité (797 espèces d'arthropodes et 114 espèces de plantes) et nos résultats ont révélé l'existence de contrôles ascendants et descendants positifs de cette biodiversité au sein des communautés. Nous avons également mis en évidence les services et disservices des espèces dominantes de fourmis envahissantes : deux d'entre elles fournissent un service de prédation et l'une d'elles réduit la diversité des ennemis naturels omnivores, ce qui semble expliquer la relation négative entre la diversité des omnivores et le service de prédation. Enfin, nous avons montré l'effet positif de la diversité des parasitoïdes et de la diversité des prédateurs, respectivement sur l'abondance des populations de la Cochenille des Seychelles et sur le service de prédation. Le seul effet significatif du paysage qui a été décelé est l'effet positif de la proportion des vergers de manguiers sur l'abondance du Thrips Sud-Africain des agrumes. L'ensemble de ces résultats nous permet d'identifier deux leviers pour la protection agroécologique des vergers de manguiers : l'implantation d'enherbements diversifiés dans les vergers ; la gestion collective du paysage en y limitant la proportion des vergers de manguiers.

A precise estimation and the characterization of the spatial variability of microclimate conditions (MCCs) are essential for risk assessment and site-specific management of vector-borne diseases and crop pests. The objective of this study was to estimate at local scale, and assess the uncertainties of Surface Microclimate Indicators (SMIs) derived from airborne infrared thermography and multispectral imaging. SMIs including Surface Temperature (ST) were estimated in southern Quebec, Canada. The formulation of their uncertainties was based on in-situ observations and the law of propagation of uncertainty. SMIs showed strong local variability and intra-plot variability of MCCs in the study area. The ST values ranged from 290 K to 331 K. They varied more than 17 K on vegetable crop fields. The correlation between ST and in-situ observations was very high (r = 0.99, p = 0.010). The uncertainty and the bias of ST compared to in-situ observations were 0.73 K and ±1.42 K respectively. This study demonstrated that very high spatial resolution multispectral imaging and infrared thermography present a good potential for the characterization of the MCCs that govern the abundance and the behavior of disease vectors and crop pests in a given area. (Resume d'auteur)

Copper-based compounds are widely used in integrated pest management (1PM) programs aiming at controlling agriculturally important plant bacterial pathogens and the latter have adapted in response to this selective pressure. Copper resistance of Xanthomonas citri pv. citri (Xcc), a major citrus pathogen worldwide causing Asialie citrus canker, was first observed in Argentina two decades ago and subsequently reported as a copLAB-based, plasmid-encoded system. The emergence of resistant strains has since been reported in Réunion (South West lndian Ocean) and Martinique (Eastern Caribbean Sea). Disease severity was found markedly increased in groves established with susceptible cultivars and infected with copper-resistant Xcc. Using tandem repeat-based genotyping and copLAB PCR, we demonstrated that the genetic structure of the copperresistant strains from these three regions was made up of two distant clusters and varied for the detection of copLAB amplicons. ln order to investigate this pattern more closely, we sequenced six copper-resistant Xcc strains from Argentina, Martinique and Réunion, together with reference copper-resistant Xanthomonas and Stenotrophomonas strains using long-read sequencing technology. Genes involved in copper resistance were found to be strain-dependent with the nove! identification in Xcc of copABCD and a eus heavy metal efflux resistance-nodulation-division system. The genes providing the adaptive trait were part of a mobile genetic element similar to Tn3-like transposons and included in a conjugative plasmid. The mining of ail bacterial genomes available from public databases suggested that the mobile elements containing copper resistance genes and their plasmid environments were primarily detected in the Xanthomonadaceae family.

Earth has recently entered the new era of the Anthropocene, during which the rise of human activities are impacting for the first time ecosystems and climate on the global scale. Since the 1960s the green revolution has improved food production in quantity using industrially-designed agriculture, which has led to global pollution by pesticides and losses of food quality, biodiversity and soil carbon. As a consequence there is a need to implement agroecological practices in order to produce food safely and in a sustainable way. This virtual issue presents principles and applications of agroecological engineering, exemplified in 19 selected review articles from the journal Agronomy for Sustainable Development, one of the most recognized journals in Agronomy. Practical examples of agroecological engineering include ecological pest control, intercropping, multiple cropping systems, biofertilisation, or the management of important components of agroecosystems such as ditches in landscapes, weeds and bees, and soil biodiversity. On the whole, this virtual issue covers a large range of topics and systems in temperate and tropical environments.

BACKGROUND: In tropical countries, netting is an effective sustainable tool for protecting horticultural crops against Lepidoptera, although not against small pests such as Bemisia tabaci, while smaller mesh netting can be used in temperate regions. A solution is to combine a net with a repellent. Previously we identified repellent essential oils: lemongrass (Cymbopogon citratus ), cinnamon (Cinnamomum zeylanicum), cumin (Cuminum cyminum) and citronella (Cymbopogon winternarius). The present study was designed to identify the active compounds of these essential oils, characterise their biological activity and examine their potential for coating nets. We investigated the efficiency and toxicity of nets dipped in different solutions. We then studied the repellent effect with an olfactometer and the irritant effect by video tracking. RESULTS: Geraniol and citronellol were the most promising net coatings owing to their repellent effect. The repellency, irritancy or toxicity varied with the product and concentration, and these features were independent, indicating that the repellent and the irritant/toxic mechanisms were not the same. The combined effects of these different compounds account for the bioactivity of the mixture, suggesting interactions between the compounds. CONCLUSION: This new sustainable strategy for protecting vegetable crops against white flies is discussed, in addition to the use of companion plants that could produce such bioactive compounds.

INRA/Portail actus/Entreprises, Monde agricole (18/04/2016); National audience

International audience; Comment concilier la protection des cultures vis-à-vis des ravageurs et des maladies avec la durabilité socioéconomique, écologique, environnementale et sanitaire des agroécosystèmes ? Face aux limites du système actuel, comment assurer la transition des techniques de lutte préconisées et établies par la protection intégrée des cultures, vers la protection agroécologique des cultures ou PAEC, cette méthodologie innovante de gestion des peuplements d'un agroécosystème ? À partir d'une présentation des principes de l'agroécologie et de leur application à la protection des cultures, complétée d'une revue critique de l'évolution de celle-ci, cet ouvrage analyse plusieurs expériences participatives réalisées en vraie grandeur, dans différents contextes. Il en tire des recommandations concrètes pour l'ensemble des systèmes de cultures tempérés et tropicaux, véritables clés de cette transition agroécologique recherchée. Les contributions des 56 auteurs, d'horizons variés, traduisent le besoin et les attentes de la communauté scientifique et agricole. Leur expérience dans la recherche, l'enseignement, la formation et le transfert en milieu producteur, ainsi que la rigueur de leur raisonnement scientifique, donnent à l'ouvrage sa profondeur et son originalité. Ils en font un support d'information actualisé pour les professionnels et d'enseignement pour les étudiants en agronomie, protection des cultures, gestion de la biodiversité ou agroécologie.

La culture de l'ananas en Guyane française est confrontée à des pourritures des fruits dues à plusieurs champignons dont les vecteurs ne sont pas identifiés. Des tests ont montré l'efficacité de la protection des fruits à l'aide de filets. Cet article présente des résultats d'essais de différents filets portant sur les taux de pourriture, les rendements, la qualité des fruits et le bilan économique de leur utilisation.

Guide de référence du jardinage sous les tropiques, Mon jardin tropical, vous apprendra à cultiver près de 550 espèces à travers 504 pages et 763 photographies ; que vous soyez aux Antilles, en Guyane, à la Réunion... ou en Europe !

Online first; Les cultures OGM demeurent un sujet de controverse malgré leur adoption rapide là où elles ont été autorisées. Depuis 20 ans, un important thème de débat a été leur impact sur les quantités de pesticides épandus, notamment pour les cultures tolérantes à un herbicide (TH). Pour les uns, elles entraînent, par comparaison aux cultures conventionnelles, une diminution des herbicides employés tandis que pour d'autres, c'est l'opposé. Depuis 1996, les OGM les plus répandus ont été les cultures TH, qui impliquent l'usage d'un herbicide associé, en général le glyphosate. Lors des toutes premières années de leur diffusion, les cultures TH ont souvent conduit à une légère réduction des herbicides. Mais la répétition de ces cultures et des épandages de glyphosate sans alternance ni diversité suffisantes a contribué depuis plus de 10 ans à l'apparition d'adventices résistantes au glyphosate qui induisent une hausse des quantités de glyphosate et d'autres herbicides. Utilisant des données récentes et une approche multidisciplinaire, l'article analyse cette situation et les impacts des adventices résistantes aux herbicides. Sont examinées l'expansion des OGM tolérants aux herbicides dans le monde et leurs répercussions en matière de traitements herbicides, en particulier aux Etats-Unis. La progression mondiale des adventices résistantes au glyphosate et leurs impacts notamment sur la culture du soja aux États-Unis sont étudiés ensuite. La dernière partie explore comment les grandes firmes semencières, les agriculteurs et les spécialistes en malherbologie cherchent à faire face à cette propagation d'adventices résistantes. Enfin la conclusion aborde de façon plus large les tendances des cultures OGM

Lysozymes are bacteriolytic peptides that are implicated in the insect nonspecific innate immune responses. In this study, a full-length cDNA encoding a c-type lysozyme from Schistocerca gregaria (SgLys) has been cloned and characterized from the fat body of immune-challenged 5th instar. The deduced mature lysozyme is 119 amino acid residues in length, has a calculated molecular mass of 13.4 kDa and an isoelectric point of 9.2. SgLys showed high identities with other insect lysozymes, ranging from 41.5% to 93.3% by BLASTp search in NCBI. Eukaryotic in vitro expression of the SgLys ORF (rSgLys) with an apparent molecular mass of ~ 16 kDa under SDS-PAGE is close to the calculated molecular weight of the full-length protein. rSgLys displayed growth inhibitory activity against Gram-negative and Gram-positive bacteria. 3D structure modeling of SgLys, based on comparison with that of silkworm lysozyme, and sequence comparison with the helix-loop-helix (α- hairpin) structure of hen egg white lysozyme (HEWL) were employed to interpret the antibacterial potencies. Phylogenetic alignments indicate that SgLys aligns well with insect c-type lysozymes that expressed principally in fat body and hemocytes and whose role has been defined as immune related. Western blot analysis showed that SgLys expression was highest at 6-12 h post-bacterial challenge and subsequently decreased with time. Transcriptional profiles of SgLys were determined by semi-quantitative RT-PCR analysis. SgLys transcript was upregulated at the highest level in fat body, hemocytes, salivary gland, thoracic muscles, and epidermal tissue. It was expressed in all developmental stages from egg to adult. These data indicate that SgLys is a predominant acute phase protein that is expressed and upregulated upon immune challenge.

Cet ouvrage traite des conditions et des modes de gestion de la culture du cotonnier, plus particulièrement en Afrique, de la semence à l'utilisation des produits, en se reposant sur les résultats de recherche. Des recommandations pratiques sont formulées à l'intention de tous les acteurs de la filière coton. Ainsi, l'intérêt d'améliorer la production du cotonnier et sa qualité est abordé sous tous les aspects de la culture par des spécialistes dans une approche systémique. Cet ouvrage propose au lecteur professionnel une aide à la décision en agronomie et en gestion des systèmes de culture, sans oublier les aspects phytosanitaires. Il informe également sur l'impact du changement climatique, sur les modalités de la transformation et de l'usage des produits et coproduits. Enfin, l'Analyse de cycle de vie appliquée à l'évaluation environnementale des systèmes cotonniers enrichit particulièrement la manière d'organiser et d'optimiser les différentes étapes de cette production d'importance mondiale. L'objectif de cet ouvrage est de proposer des pratiques agricoles et des recommandations pour l'avenir, contribuant ainsi à améliorer la culture du cotonnier et la qualité de ses produits. Rédigé dans un langage accessible, cet ouvrage est destiné à tous les professionnels de terrain.

Generalist predators such as the weaver ant, Oecophylla longinoda(Latreille), play an important role as biological control agents in West African orchards and, by extension, also in forest and savanna ecosystems within sub-Saharan Africa. These weaver ants are one of the most effective and effi cient predators of arthropods in perennial tropical tree crops; their presence also acts as a deterrent to insect herbivores, particularly tephritid female fruit fl ies, due to the semiochemicals they produce. Emerging African markets for organic and sustainably- managed fruits and nuts have encouraged an interest in the use of weaver ants. Protection of tropical forests and savannas is ecologically and environmentally crucial and also essential for the protection of O. longinoda.

Conventional crop protection with pesticides has limitations such as resistance of pests to pesticides and faunal imbalance. Agroecological crop protection is an attractive alternative based on the principles of agroecology. We present here this strategy using the case of Cucurbitaceae flies, which are the most important agricultural pests in Réunion. Research has been carried out on the bioecology of these insects and on the effectiveness of agroecological techniques. The main points are the following: the number of species of vegetable flies increased in the southern summer. Adult flies spend more than 90 % of their time on nonhost plants, with specific circadian rhythms. Several original agroecological techniques were designed, such as sanitation using augmentoria; trap plants, e.g., maize; adulticide bait; and the creation of habitats for predatory arthropods. Local growers are very satisfied with the results. They have reduced insecticide use with substantial cost savings and they have observed a decrease in losses and a lower phytosanitary workload. The education and training of students, professionals, and the general public has been a major aspect of this project. Increased knowledge of flies and agroecological management strategies of their populations can now be combined with modeling tools to facilitate the extension of the program to other areas or for educational purposes. Practices are currently being extended to other areas of the island and other countries of the Indian Ocean. This project is both a significant milestone for organic farming in Réunion and a precedent for other initiatives aimed at reducing or eliminating pesticides.

International audience; Modern agriculture suffers from its dependence on chemical inputs and subsequent impacts on health and environment. Alternatively, protecting crops against pests can be achieved through the reinforcement of regulation ecological services. Our work propounds a data-driven methodological framework to derive relevant agricultural landscape rearrangements enhancing populations of beneficial organisms regulating pests.Building on spatialised entomological and geographic data, we developed a parsimonious reaction–diffusion model describing the population dynamics of beneficial organisms. Parameter estimation was carried out in a Bayesian framework accounting for uncertainty in the measurement.Thousands of agricultural landscapes were generated under agronomic specifications dealt with as constraint satisfaction problems. Population dynamics was simulated on each landscape with the fitted reaction-diffusion model mentioned above, and two metrics of abundances allowed the assessment of the regulation performance of the landscape spatial arrangements. One metric is a mean field performance criterion assessing the regulation performance from the landscape composition only, the other is a spatial performance metric assessing the performance resulting from the whole landscape spatial configuration. The former is computed with a non-spatialised form of the population dynamics model, the latter results from the reaction-diffusion model of the population dynamics. Comparing these metrics enabled to quantify the impact of spatial arrangements, hence allowing arrangements proposals. This framework was applied to the case study of a ground beetle species involved in the biological regulation of weeds. The arrangement proposals abides by the productive agronomic constraint that is the landscape composition, while they allow for significant habitat quality enhancement (or deterioration) for the beneficial organism (or a pest). Minor adaptations of our integrated data-driven approach would suit numerous situations ranging from the provision of enhanced ecosystem services to land management for conservation.

Due to a growing demand of food production worldwide, new strategies are suggested to allow for sustainable production of food with minimal effects on natural resources. A promising alternative to the application of chemical pesticides is the implementation of crops resistant to insect pests. Plants produce compounds that are harmful to a wide range of attackers, including insect pests; thus, exploitation of their natural defense system can be the key for the development of pest‐resistant crops. Interestingly, some plants possess a unique first line of defense that eliminates the enemy before it becomes destructive: egg‐killing. Insect eggs can trigger (1) direct defenses, mostly including plant cell tissue growth or cell death that lead to eggs desiccating, being crushed or falling off the plant or (2) indirect defenses, plant chemical cues recruiting natural enemies that kill the egg or hatching larvae (parasitoids). The consequences of plant responses to eggs are that insect larvae do not hatch or that they are impeded in development, and damage to the plant is reduced. Here, we provide an overview on the ubiquity and evolutionary history of egg‐killing traits within the plant kingdom including crops. Up to now, little is known on the mechanisms and on the genetic basis of egg‐killing traits. Making use of egg‐killing defense traits in crops is a promising new way to sustainably reduce losses of crop yield. We provide suggestions for new breeding strategies to grow egg‐killing crops and improve biological control.

Grain legumes play an important role in community livelihood and in the national economy in Kenya. Unfortunately, in many African countries, production doesn't satisfy the demand in grains due to various constrains. Understanding farmers practices and behavior in the management of grain legume pests is a crucial step in the development of sustainable management strategies. A total of 216 farmers were surveyed in eight districts of eastern Kenya to evaluate farmers' knowledge and perceptions of grain legume pests; to examine current pest management practices, and to identify other production constraints. Grain legumes are grown by a wide age-group of farmers, with both genders equally represented. Chemical control remains the main pest management strategy, and, to ensure pesticide effectiveness, farmers also use increased application rates, chemical alternation, frequent application and mixtures of chemicals. While farmers used other control measures, they showed only limited interest in biological control. The majority of the farmers had experience in grain legume farming and were able to identify the major pests, which were the legume flower thrips Megalurothrips sjostedti Trybom, the cowpea aphid Aphis craccivora Koch and the legume pod borer Maruca vitrata Fabricius. Our survey revealed that education and proximity to extension services contributed significantly to farmers' knowledge of grain legume pests, suggesting the need to provide continuous training and capacity building on integrated pest management in grain legume farming. The study also suggests integration of other pest management strategies such as the use of early maturing varieties, biopesticides and biofertilizer to reduce the use of chemical for sustainable pest management.

Fruit flies (Diptera: Tephritidae) are amongst the most destructive and widespread pests of fruits and vegetables in the Indian Ocean Islands (Comoros, Mayotte, Madagascar, Reunion Island, Republic of Mauritius and Seychelles). In Mauritius, the bait application technique (BAT) and the male annihilation technique (MAT) have been used successfully to suppress populations of Bactrocera zonata, Ceratitis rosa and Ceratitis capitata in backyards over an area of 300 km2. Population suppression of B. zonata was further improved in one 10 ha area by weekly releases of sterile flies (sterile insect technique [SIT]). Area-wide fruit fly control in cucurbit plantations in selected localities was initiated with the support of the International Atomic Energy Agency. BAT, MAT and sanitation were used in farmers’ fields to suppress populations of Zeugodacus cucurbitae, Dacus demmerezi and Dacus ciliatus. Farmers used fewer pesticides while cucurbit infestation by fruit flies was reduced from >30 % to