Dr N’GUESSAN Walet Pierre a un Doctorat Unique en Organismes-environnement et production spécialité Entomologie et Gestion des Ecosystèmes de l’Université Félix HOUPHOUËT-BOIGNY. Il est également Ingénieur agronome option défenses des cultures depuis Juillet 2008, diplômé de l’Institut National Polytechnique Félix Houphouët-Boigny de Yamoussoukro en Côte d’Ivoire.
Depuis Juin 2023, il est Chef du Programme cacao du Centre National de Recherche Agronomique (CNRA) où il travaille depuis mars 2009 comme chercheur, entomologiste.
Il travaille sur la lutte contre la maladie du swollen shoot qui implique l’étude des vecteurs, la mise au point de lutte intégrée contre la maladie du swollen shoot. Il travaille également sur les autres insectes nuisibles du cacaoyer dont il contribue à la mise au point de lutte biologique.
Il a été coordonnateur de plusieurs projets et intervient dans de nombreux projets et conventions.
RESEARCH, TEACHING, or OTHER INTERESTS
Agricultural and Biological Sciences, Agronomy and Crop Science, Ecology, Evolution, Behavior and Systematics, Insect Science
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Scopus Publications
Scopus Publications
Inventory and abundance of mealybug species in immature and mature cocoa farms in Côte d'Ivoire Pierre Walet N'Guessan, Ahoua Yapi, François Kouamé N'Guessan, Norbert N'Dri Kouamé, Christiane Nathalie Gouamené, Romain Aka Aka, Klotioloma Coulibaly, Mathias Gnion Tahi, Boaké Koné, Emmanuel Koffi Kassin, Evelyne Marise Assi, Brigitte Honorine Sahin Boguinard Guiraud, Alain Acka Jacques Kotaix Journal of Applied Entomology, 2019 From 2013 to 2018, surveys were conducted in counties not previously surveyed in order to determine species of mealybugs present in the cocoa orchard in Côte d'Ivoire as well as their abundance according to the age of cocoa trees. Immature and mature cocoa trees were inspected to hand‐height in 5 and 29 counties infected with Cacao swollen shoot virus (CSSV). In each cocoa farm, mealybugs were searched for on fruits, leaves, flowers, twigs and trunks. Mealybug species were identified, and colonies were counted. Five mealybug species were identified on immature cocoa trees: Ferrisia virgata, Formicococcus njalensis, Planococcus citri, Planococcus kenyae and Pseudococcus longispinus. In addition to these species, four species, Dysmicoccus brevipes, Maconellicoccus hirsutus, Phenacoccus hargreavesi and Pseudococcus jackbeardsleyi were identified on mature cocoa trees. On immature cocoa trees, Fo. Njalensis, Pl. citri and Ps. longispinus comprised were, respectively, 35%, 33% and 19% of colonies, respectively. On mature cocoa trees, Fo. Njalensis and Pl. citri comprised 63.2% and 21.0%, and others species 15.8%. Nevertheless, the abundance of mealybug species varied according to the age of cocoa trees. The preferred organs of mealybugs were pods (74.1%) followed by twigs (13.4%) and flowers (7.4%). Previously, the mealybug Paracoccus burnerae (Brain) was found on Theobroma cacao, which is the first record for this species in Côte d'Ivoire and on this host‐plant.
First record of Pseudococcus jackbeardsleyi (Hemiptera: Pseudococcidae) from Africa, côte d'Ivoire Pierre Walet N'Guessan, Gillian W. Watson, Judith K. Brown, François K. N'guessan Florida Entomologist, 2014 Cocoa swollen shoot virus disease is an important virus disease of cocoa occurring mainly in West Africa. Mealybugs are known to be vectors of the pathogen, Cacao swollen shoot virus. Since recent outbreaks in Côte d'Ivoire, studies have been undertaken on different aspects of the disease. During 2013, surveys were conducted to identify mealybug species infesting aerial parts of cocoa (Theobroma cacao L.; Malvales: Malvaceae) trees at various sites and the samples were authoritatively identified using morphological characters. A species new to Africa, Pseudococcus jackbeardsleyi Gimpel & Miller (Hemiptera: Pseudococcidae), was found at 2 localities in Côte d'Ivoire, i.e., Buyo (Soubré county) and Gbalékro (Agboville county). Hosts of this polyphagous mealybug belong to 47 plant families and include banana, eggplant, Hibiscus spp., potato, sweet pepper and tomato. Virus transmission by P. jackbeardsleyi has not been recorded, but it belongs to the same genus as P. maritimus (Ehrhorn), which transmits Little cherry virus 2 to sweet cherry, and P. longispinus (Targioni Tozzetti), which transmits Grapevine A trichovirus (GAV) to grapevine and Cacao swollen shoot virus (CSSV) to cocoa. The introduction and establishment of P. jackbeardsleyi in Africa may have a considerable impact on both commercial and subsistence agriculture.
