N’klo, H., Bajougué, D., Achille, N.A., Martin, K., Alphonse, N.Y., & Mamadou, D. 2011 Population dynamics of the mango mealybug, Rastrococcus invadens Williams (Homoptera: Pseudococcidae) in northern Côte d'Ivoire. Journal of Animal & Plant Sciences 12(1): 1481-1492

Notes: To collect data for a biological control strategy against mango mealybug (Rastrococcus invadens), the infestation of three varieties of mango (Kent , Keitt and Early Gold) were studied. The periods of R. invadens fluctuations and those of its two main natural enemies, the parasitoids Gyranusoidea tebygi and Anagyrus mangicola, the impact of parasitoids/hyperparasitoids complex and the influence of abiotic factors on mealybug/parasitoids complex, were also studied. Dynamics of pest primary and secondary parasitoids was measured from September 1999 to September 2000 in northern Côte d'Ivoire, the main producing region of mangoes and the most affected by negative effects of R. invadens. Live (adults and larvae), dead and mummified mealybugs, were counted directly in the field on 20 leaves per tree. Primary and secondary parasitoids were identified and counted at their emergence from full mummies, after 2 weeks of incubation in laboratory at room temperature. Keitt was more infested by the pest, followed by Kent then Early Gold. R. invadens population is more abundant in rainy season than in dry season. Under natural conditions in northern Côte d'Ivoire, mealybug is able to develop five generations from 60 to 70 days per year. Abiotic factors that appear to affect populations of pest are mainly rainfall and temperature variations and to a lesser extent humidity. The level of live and dead insects is positively correlated with rainfall in contrast to temperature variations. With only 17.95 % of parasites developed by G. tebygi and A. mangicola on mealybug, their impact seems weak on the pest. Gyranusoidea tebygi and Anagyrus mangicola are attacked in their turn by several hyperparasitoids including Marietta Léopardina and Chartocerus hyalipennis as the most important when considering their level of hyperparasitism (about 65.18 %). Mass production of G. tebygi and A. mangicola and their release is considered to control R. invadens. The presence of hyperparasitoids responsible of high level mortality of parasitoidsis, however, represents a constraint. The best periods suited to mass production of G. tebygi and A. mangicola are from February to September and for first releasing, from March to April.