To cope with a biological invasion, such as Hoplochelus marginalis introduced into Reunion in 1981, implementation of an integrated pest management strategy is crucial in the current socio-environmental context. This paper evaluates the impacts of designing and adopting a biocontrol strategy based on the entomopathogenic fungus Beauveria, developed in collaboration with stakeholders: growers, millers, local organizations (research, development, administrative, etc.), and society. The adopted methodology, called ImpresS by CIRAD, consists in describing the process of an innovation using four interconnected tools: the innovation story, stakeholder mapping, capacity building generated by the innovation, and the impact pathway. The impact pathway model consists in relating the process of the innovation using a factual approach, bringing out the outputs resulting from the innovation, with their outcomes and with their direct and indirect impacts. The description of the process is established using the literature and it is improved using personal and group interviews with growers, local organizations and other stakeholders. The challenge for this approach was to obtain a shared perception of the process by all the stakeholders. The results, based on 70 interviews, showed immediate positive economic impacts for growers, the local sugar sector and the companies distributing the innovation's two products, i.e. Betel® and sporized rice. Another impact is environmental, with no water pollution by an insecticide (chlorpyrifos) that was used before biological control was implemented. Among the indirect impacts, using a successful biological technique with low impact on the environment promoted the quality of sugar marketed internationally, thereby maintaining the subsidy from the European Union. Other impacts were seen at the international level. This retrospective review represents a prototype for other sugar-producing countries to help them in analysing and understanding the adoption of such a successful strategy. (Resume d'auteur)

Les avancees et les resultats du projet Biophyto ont fait l'objet de diverses actions de formation, d'information et de communication. Deux sessions de formation diplomante (Certificat Universitaire de Qualification Professionnelle) ont ete dispensees aupres de 27 candidats (techniciens OP, agriculteurs, conseillers agricoles). Des informations regulieres ont ete diffusees par le biais du site internet Bio et Agri, Diversite et Culture Ocean indien . Une Newsletter trimestrielle a egalement ete envoyee a plus de 500 destinataires pour les tenir informes de l'etat d'avancement du projet. Des actions de communication ont ete entreprises lors de manifestations agricoles locales et du seminaire ECOPHYTODOM. Divers documents pedagogiques illustrant le retour d'experience du projet sont en cours d'edition. Ils constitueront a terme des supports de transfert pour assurer la diffusion des techniques de protection agroecologique aupres du public agricole de La Reunion et de l'Ocean indien. (Resume d'auteur)

La valorisation des resultats et la preparation au transfert du projet Biophyto prennent plusieurs formes. L'une d'elles s'opere via la mise en place d'un CUQP (Certificat Universitaire de Qualification Professionnelle) en Protection agroecologique des cultures. Cette formation diplomante vise a former les professionnels a la protection agroecologique des cultures (PAEC). Organisee et delivree par l'Institut Universitaire Technologique de l'Universite de La Reunion, cette formation est originale dans sa forme, puisqu'elle est dispensee, de maniere coherente et complementaire, par un consortium de partenaires du projet Biophyto. Cette formation est aussi originale dans son contenu : elle integre a la fois les principes de l'agroecologie declinee a la protection des cultures et les resultats de son application sur le terrain, a travers plusieurs projets. Deux sessions de formation ont ete organisees en 2013 et en 2014, diplomant 26 apprenants, pour la plupart agriculteurs ou techniciens agricoles. C'est la premiere formation diplomante de ce type destinee aux professionnels et permettant l'acquisition de competences dans le domaine novateur de l'agroecologie. (Resume d'auteur)

CUQP/PAEC. : Un CUQP (Certificat Universitaire de Qualification Professionnelle) est une formation universitaire destinee a repondre a un besoin precis du monde professionnel. Elle complete les formations diplomantes de l'Education Nationale et de l'Enseignement Superieur, en proposant aux etudiants d'acquerir une qualification operationnelle reconnue dans la mise en oeuvre de techniques nouvelles et de developper les competences associees a des metiers specifiques. Developpe dans le cadre du projet BIOPHYTO' ayant pour finalite de proposer des pratiques de culture de mangues sans insecticide, le CUQP PAEC [Protection Agroecologique des Cultures] est la premiere formation diplomante destinee aux professionnels et permettant l'acquisition de competences dans le domaine novateur de l'agroecologie. Le present ouvrage reprend de facon synthetique, a destination d'un public cherchant a mieux connaitre les principes et l'efficacite de l'agroecologie a la protection des cultures, les principaux themes abordes au cours de la formation. (Resume d'auteur)

Three fruit flies (Diptera : Tephritidae) damage cucurbit crops on Reunion Island : Bactrocera cucurbitae (Coquillet), Dacus demmerezi (Bezzi) and D. ciliatus (Loew). Chemical control does not provide any satisfactory control of fly populations. The GAMOUR project aims at promoting agroecological management of these pests. The present work is aimed at studying the augmentative releases of the parasitoid Psyttalia fletcheri (Silvestri) (Hymenoptera : Braconidae) as a biological control agent. From 2010 to 2011, four trials were set up. We released between 1,600 to 3,000 parasitoid wasps according to the trial. The parasitism rate of P. fletcheri was then recorded using fruit samples collected in the field. Parasitism was almost null before the releases. After the releases, mean parasitism rates increased moderately with a maximum of 16.7%. The parasitism was moreover null on crops where no B. cucurbitae were caught. In light of a cost-benefit analysis, releases of P. fletcheri appear therefore irrelevant. On the other hand, inoculative releases of parasitoids in low altitude agrosystems (B. cucurbitae is present below 800 m) could locally increase the abundance of wasps and promote environmentally friendly methods to growers.

Les lâchers inondatifs de parasitoides oophages du genre Trichogramma sont tres largement utilises en lutte biologique dans le monde et couvre 32 millions d'hectares de cultures (y compris de la canne a sucre) et forets. A la Reunion, nous elaborons depuis plus de 10 ans une strategie de lutte biologique par lâchers inondatifs de la souche Saint Benoit de Trichogramma chilonis Ishii (Hymenoptera: Trichogrammatidae) contre Chilo sacchariphagus Bojer (Lepidoptera: Crambidae), strategie qui est issue d'une collaboration fructueuse entre l'INRA, la FDGDON et le CIRAD. De l'identification du meilleur auxiliaire a la production de masse en passant par les essais de terrain, des ameliorations ont ete constamment apportees. Les essais experimentaux ont montre une reduction jusqu'a 50% des degâts avec des gains economiques non negligeables de 700 a 1400 euros par hectare. Pour developper cette strategie de lutte biologique a grande echelle, il est necessaire de reduire les couts de production des auxiliaires et de main d'oeuvre au champ. Entre 2008 et 2011, nous avons mis en evidence une quiescence permettant un stockage au froid de T. chilonis sur plusieurs mois sans perte de performance. Grâce a ce stockage, l'efficacite de la production de masse et de la gestion des lâchers est nettement amelioree. Un partenariat de longue date avec Biotop, une biofabrique francaise qui possede une experience confirmee des lâchers inondatifs de trichogrammes contre la pyrale du mais en France, assurera la disponibilite de ce traitement pour tous les volontaires de la filiere. Le transfert en milieu producteur en est desormais dans sa premiere phase avec l'appui du CTICS pour la diffusion de la strategie aupres des planteurs. (Resume d'auteur)

The evolution of life is characterized by major evolutionary transitions during which independent units cooperated and formed a new level of selection. Relatedness is a common mechanism that reduces conflict in such cooperative associations. One of the latest transitions is the evolution of social insect colonies. As expected, they are composed of kin and mechanisms have evolved that prevent the intrusion of nonrelatives. Yet, there are exceptions an extreme case is the fusion of unrelated colonies. What are the advantages of fusions that have colonies with a high potential for conflict as a consequence? Here, we investigated fitness costs and benefits of colony fusions in a lower termite species, Cryptotermes secundus, in which more than 25% of all colonies in the field are fused. We found two benefits of colony fusion depending on colony size: very small colonies had an increased probability of survival when they fused, yet for most colony sizes mainly a few workers profit from colony fusions as their chance to become reproductives increased. This individual benefit was often costly for other colony members: colony growth was reduced and the current reproductives had an increased chance of dying when fusions were aggressive. Our study suggests that fusion of colonies often is the result of ‘selfish’ worker interests to become reproductives, and this might have been important for the termites' social evolution. Our results uniquely shows that selfish interests among related colony members can lead to the formation of groups with increased potential for conflict among less related members.

For over ten years, a biological control strategy by inundative release of Trichogramma chilonis (Hymenoptera: Trichogrammatidae) against Chilo sacchariphagus (Lepidoptera: Crambidae) has been studied (French collaboration between INRA, CIRAD and FDGDON Reunion Island). Many key steps were elaborated the last years regarding the pest and beneficial insects. Strategies of biological control, mass production, and field releases were also investigated. Important results were obtained such as: (i) population dynamic of Chilo sacchariphagus and damage, (ii) efficacy of the egg parasitoid Trichogramma chilonis, (iii) strategies of insect release (period, dose, frequency, adapted packaging, and delayed emergence), (iv) optimization of mass production, (v) cold storage, (vi) field release methods and checking of field efficacy. An IPM strategy associating inundative release of an egg parasitoid, T. chilonis and conservation of a predatory ant, Pheidole megacephala, has been proposed. According to field experiments in Reunion Island, this reduced up to 50% of damage with financial gains ranging from 800 to 1800 dollars per ha. Successful long-term storage of T. chilonis and its good efficacy in field after cold storage make possible a large-scale application of IPM strategies in sugarcane production. (Resume d'auteur)

The stem borer Chilo sacchariphagus is a key pest of sugarcane in Reunion Island and South-East Asia. Since 2002, an IPM strategy associating inundative release of an egg parasitoid, Trichogramma chilonis, and conservation of a predatory ant has been proposed. This reduced up to 50% of damage in field experiments in Reunion Island (financial gains from $800 to $1800/ha). To develop IPM strategies on a large scale, reducing the global costs is necessary. In this context, cold storage is a key step to the development of the sugarcane borer biocontrol, by improving production and release management. Thanks to a French funding (CASDAR), laboratory tests on cold storage of T. chilonis were first conducted, followed by field experiments on the performance of stored parasitoids. Quality control after storage was performed several times (after mass production, before and after transport, after field release) in laboratory at 25 ± 1°C, RH 75 ± 5 % and 16L: 8hD to evaluate emergence rate of stored insects, fecundity during 7 days and survival at 7th day of T. chilonis females. For the first time, a long-term cold storage of T. chilonis was obtained without loss of physiological performance (good emergence, fecundity, survival during 7 days). Results suggested a quiescence state because no loss was observed due to storage interruption. Moreover, the same field efficacy of cold stored Trichogramma compared to non-stored individuals was obtained in Reunion Island. These important results make possible a large-scale application of IPM strategies in sugarcane production. (Resume d'auteur)

Les Mouches des legumes representent un fleau majeur en maraichage. A La Reunion, trois especes attaquent les cucurbitacees. La lutte chimique est insatisfaisante et ses consequences socio-economiques, environnementales et sanitaires sont incompatibles avec la notion d'agriculture durable. Pour sortir de l'impasse dans laquelle se trouvent les agriculteurs, l'enjeu est de passer de recettes agrochimiques a des pratiques agroecologiques. Quatorze organismes partenaires se sont ainsi reunis dans le projet GAMOUR (Gestion Agroecologique des MOUches des legumes a la Reunion). Ce projet de recherche-developpement (2009-2011), vise a proposer des pratiques agricoles durables aux agriculteurs, par la conception d'innovations technologiques, la formation des agriculteurs, et in fine le transfert de ces innovations agroecologiques en milieu producteur. (Resume d'auteur)

La culture des cucurbitacees a la Reunion est un exemple d'antagonisme entre pratiques agricoles intensives et agriculture durable. Ces legumes sont attaques par des mouches de la famille des Tephritidae qui causent de tres lourds degâts en depit des grandes quantite d'insecticides utiliisees. Le projet GAMOUR (200-2011) a pour ambition d'apporter une reponse agroecologie a ce probleme. Il est mene par 14 organismes de recherche et developpement agricole de la Reunion dans l'objectif commun de developper et transferer aux agriculteurs une methode durable de gestion de ces ravageurs. Depuis mi-2009, une vingtaine de producteurs (en agriculture "conventionnelle" ou biologique) testent l'application d'un paquet technique baptise SP5 qui repond aux fondamentaux d'une protection agroecologique des cultures. Cet article cle presente les principes et l'organisation de Gamour. A mi-parcours, les premiers resultats sont encourageants: la periode restante nous servira la methode avant de pouvoir l'etendre au dela des zones pilotes. (Resume d'auteur)

BIOCONTROL of sugarcane stemborers using Trichogramma releases is a common strategy used in numerous countries, and the efficacy of such releases has been proven in most cases. On Reunion Island, the key stemborer Chilo sacchariphagus and its egg parasitoid Trichogramma chilonis have been the subject of intensive research for 10 years. From the identification of the best candidate for biocontrol to mass production and experimental releases in sugarcane fields, improvement has been constantly made through the years, with successful results. In this paper, we report some of the important outcomes, problems encountered and questions that have arisen during the field experiments (Reunion) and laboratory rearing activities (Reunion and France). Behind promising results from an eco-friendly technology that is used worldwide, one of the current debates that remain is the cost of such biocontrol to the growers. Since 2008, a new research and development project has been conducted to optimise the technology of field releases as well as to increase the efficacy of mass production and storage at cold temperature. To deal with profitability and quality and establishing a new industrial process for Trichogramma production, a partnership has been formed with a French company, BIOTOP, which has extensive experience in biocontrol of the maize stemborer Ostrinia nubilalis in France.

SUMMARY During development and evolution individuals generally face a trade‐off between the development of weapons and gonads. In termites, characterized by reproductive division of labor, a caste evolved—the soldiers—which is completely sterile and which might be released from developmental trade‐offs between weapons and testes. These soldiers are exclusively dedicated to defense. First, we investigated whether defensive traits are under selection in sterile termite soldiers using allometric analyses. In soldiers of the genus Cryptotermes phragmotic traits such as a sculptured and foreshortened head evolve rapidly but were also lost twice. Second, we compared the scaling relationships of these weapons with those in solitary insects facing a trade‐off between weapons and gonads. Defensive traits consistently had lower slopes than nondefensive traits which supports the existence of stabilizing selection on soldier phragmotic traits in order to plug galleries. Moreover, soldier head widths were colony specific and correlated with the minimum gallery diameter of a colony. This can proximately be explained by soldiers developing from different instars. The scaling relationships of these termite soldiers contrast strikingly with those of weapons of solitary insects, which are generally exaggerated (i.e., overscaling) male traits. These differences may provide important insights into trait evolution. Trade‐offs constraining the development of individuals may have been uncoupled in termites by evolving different castes, each specialized for one function. When individuals in social insect are “released” from developmental constraints through the evolution of castes, this certainly contributed to the ecological and evolutionary success of social insects.

L'importance de la predation des oeufs du foreur de la canne a sucre, Chilo sacchariphagus, a la Reunion est demontree et joue un role essentiel dans le controle naturel de ce ravageur. Elle est principalement exercee par les fourmis de l'espece Pheidole megacephala. La strategie de lutte biologique que nous avons mise au point depuis quelques annees prend en compte cette action predatrice qui est particulierement benefique sur des champs de canne âges de 6 a 12 mois. Toutefois, nos resultats montrent que la predation des fourmis peut aussi avoir un effet nefaste sur l'auxiliaire utilise, Trichogramma chilonis, au cours des lâchers. En effet, de par leur comportement tres actif et leur petite taille, elles arrivent a penetrer dans les differents conditionnements testes et a attaquer les oeufs hotes et les parasitoides en cours de developpement. Pour limiter cet impact negatif, il est necessaire d'optimiser le conditionnement, le temps que les trichogrammes emergent et aillent parasiter les oeufs du ravageur. (Resume d'auteur)