Evaluation of Bacillus thuringiensis and a Parasitoid for Suppression of the Gypsy Moth123

Abstract

The microbial insecticide Bacillus thuringiensis Berliner and the parasitoid Apanteles melanoscelus Ratzeburg were evaluated against the gypsy moth, Porthetria dispar (L.), infesting an oak forest in Pennsylvania. The biotic agents were compared individually and in combination. In general, where only the parasitoid was released, foliage protection and population reduction was not significantly different from the untreated areas. Aerial application of B. thuringiensis provided foliage protection and population reduction when compared with the control or where only parasitoids were released. When the parasitoid was released in areas treated with B. thuringiensis additional foliage protection was attained. Only where the parasitoid was used with B. thuringiensis were larval populations consistently reduced at the 3 population densities tested.