Hyperparasitism in two newly introduced parasitoids, Epidinocarsis lopezi and Gyranusoidea tebygi (Hymenoptera: Encyrtidae) after their establishment in Togo.
Agricola U., Fischer H. U.
Author Affiliation: Institut für Phytopathologie und Angewandte Entomologie, Justus-Liebig-Universität, Giessen, Germany.
Bulletin of Entomological Research 81 : 127-132
Abstract : In 1988-89 the nature and degree of hyperparasitism in 2 newly introduced parasitoids of exotic mealybug plant pests were examined in Togo. Associated with the cassava pest Phenacoccus manihoti, 5 indigenous hymenopterous hyperparasitoids were found adapted to the primary encyrtid parasitoid Epidinocarsis lopezi: the signiphorid Chartocerus sp. A, the encyrtids Prochiloneurus insolitus and P. aegyptiacus, the eulophid Tetrastichus sp. and the aphelinid Marietta leopardina. The rate of hyperparasitism varied considerably (20-90%). At one sampling site, Chartocerus sp. A was the commonest species (52%), while at another P. insolitus was dominant (55%). Associated with the mango and citrus pest Rastrococcus invadens, the same hyperparasitoids were found attacking the primary encyrtid parasitoid Gyranusoidea tebygi but with the addition of Chartocerus sp. B. Hyperparasitism ranged from 56 to 86%, with Chartocerus sp. A being the most important species. Multiple parasitism was observed on several occasions. In spite of generally high hyperparasitism, no detrimental effect on the control efficiency of either primary parasitoid was noticed.