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Cerambycidae Diastocera trifasciata attacks were studied from October 2015 to September 2017 in three cashew tree orchards in the locality of Brobo in central Côte d’Ivoire. One hundred fifty-three (153) cashew trees, arranged on a diagonal from each orchard, were selected for sampling. The attacked plants and the branches cut per tree were counted every 15 days. Biotic parameters, namely phenological stages of trees, and abiotic factors, which are rainfall, relative humidity and average temperature, were recorded throughout the study. Attacks were observed from mid-September to January from the pre-flowering vegetative stage to the flowering stage. Attack period duration was therefore four and a half months per year. The peak of attacks was recorded in November with an attack rate of 88.02% in 2015 and 75.49% in 2016. No attack was recorded from February to mid-September, corresponding to the flowering, fruiting and post-harvest vegetative growth stages. This description of the attack process and the determination of D. trifasciata attack periods provides essential data for the implementation of an effective and sustainable control method of this species.

En Côte d’Ivoire, les vergers d’anacardiers du centre, centre-ouest et de l’est sont constamment attaqués par le Cerambycidae Diastocera trifasciata. Ces attaques, sans méthodes de contrôle efficaces s’amplifient au fil des années. Cette étude a été réalisée en vue d’évaluer d’une part l’efficacité d’une lutte mécanique contre les larves de D. trifasciata et d’autre part l’efficacité d’un biopesticide Neco 50 EC en comparaison avec un insecticide de synthèse Acétamipride 32 g/l + Lambdacyhalothrine 30 g/l. Les expérimentations ont été effectuées en mars 2017 et en septembre 2018 dans la localité de Brobo (centre de la Côte d’Ivoire). La lutte mécanique a consisté à retirer systématiquement toutes les branches infestées de larves de l’espèce et à les incinérer. Quant aux tests d’efficacité, 10 concentrations, à raison de 5 par produit ont été pulvérisées directement sur les adultes de D. trifasciata en conditions semi naturelles. Les résultats ont montré que la lutte mécanique a fait baisser le niveau des attaques de 100% à 35%. Concernant les insecticides, l’association Acétamipride 32 g/l + Lambdacyhalothrine 30 g/l a occasionné des taux de mortalité compris entre 70 et 100% à toutes les concentrations testées. Avec le biopesticide Neco 50 EC, des taux de mortalité supérieurs à 70% ont été enregistrés avec les concentrations de 3,3.10-4 g/ml et 2,5.10-4 g/ml en 24 h. Ces résultats ont permis de montrer l’efficacité de la lutte mécanique et des produits contre D. trifasciata. La méthode mécanique pourrait être vulgarisée pour permettre une bonne gestion préventive des attaques du ravageur dans les vergers d’anacardier. Quant à la lutte par l’insecticide biologique, des tests de confirmation devront être faits en plein champ pour mieux apprécier son efficacité.Mots clés : Analeptes trifasciata, attaques, Acétamipride, Lambdacyhalothrine, lutte intégrée, Côte d’Ivoire.   English Title: Efficacy of mechanical control associated with the biopesticide Neco 50 EC in the control of adults of Diastocera trifasciata (Coleoptera: Cerambycidae), a cashew tree branch girdler in Côte d'IvoireIn Côte d'Ivoire, cashew orchards in the central, western central and eastern parts of the country are constantly attacked by Cerambycidae Diastocera trifasciata. These attacks, without effective methods of control, have been increasing over the years. This study was carried out in order to evaluate on the one hand the efficacy of mechanical control of D. trifasciata larvae and on the other hand the efficacy of a biopesticide Neco 50 EC compared to a synthetic insecticide Acetamiprid 32 g/l + Lambdacyhalothrin 30 g/l. Experiments were carried out on March 2017 and to September 2018 in the locality of Brobo (central Côte d'Ivoire). Mechanical control consisted in systematically removing all branches infested with larvae of the species and incinerating them. As for efficacy tests, 10 concentrations, at a rate of 5 per product, were sprayed directly on adults of D. trifasciata under semi-natural conditions. Results showed that mechanical control reduced the level of attacks from 100% to 35%. The synthetic insecticide caused mortality rates between 70 and 100% at all concentrations tested. With biopesticide Neco 50 EC, mortality rates higher than 70% were recorded with concentrations of 3.3.10-4 g/ml and 2.5.10-4 g/ml after 24 h. These results demonstrated the effectiveness of mechanical control against D. trifasciata. The mechanical method could be extended to allow good preventive management of pest attacks in cashew orchards. As for control by biological insecticide, confirmatory tests will have to be carried out in the field to better assess its effectiveness.Keywords: Analeptes trifasciata, attacks, Acetamiprid, Lambdacyhalothrin, Integrated Pest Management, Côte d'Ivoire