Influence of hyperparasitoids on the exotic parasitoid Gyranusoidea tebygi Noyes (Hymenoptera: Encyrtidae) of mango mealybug on mango varieties in Guinea Savanna ecology.
Ukwela M. U.
Author Affiliation: Department of Crop Protection, University of Agriculture, P.M.B 2373 Makurdi, Benue State, Nigeria.
African Journal of Science and Technology 10 : 16-23
Abstract : Stands of naturally infested mango varieties (Local, Julie, Hindi, Pittir, Germer, Gesha, John and Dabsha) infested by Rastrococcus invadens Williams (Homoptera: Pseudococcidae) were selected in a survey of five human settlements in Benue State. Ten leaves of each mango variety were sampled every month for 24 months. Numbers of different stages of R. invadens, its parasitoid Gyranusoidea tebygi Noyes (Hymenoptera: Encyrtidae) and hyperparasitoids (Marietta leopardina Motsch, Chartocerus hyalipennis Hayat, Tetrastichus sp., Cheiloneurus sp. and Prochiloneurus aegyptiacus Mercet.) were monitored. Mean parasitism of R. invadens by G. tebygi was very low (0.82-2.2%), being higher on varieties with low infestation and less on those with high infestation. R. invadens populations on mango varieties influenced the presence and level of its parasitoid. Mango varieties had significant (P0.05) influence on the sex ratio of the parasitoid, G. tebygi. Hyperparasitoids, mainly M. leopardina and C. hyalipennis reduced primary parasitism by 43.5% on different varieties. This may account for very low parasitism of R. invadens on the mango varieties.