ABSTRACT

Field studies were conducted at Sharkia Governorate in 2000 and 2001 cotton seasons to evaluate the augmentative release of four trichogrammatids namely, Trichogramma embryophagum Hartig, Trichogramma brassicae Bezdenko, Trichogrammatoidea bactrae Nagaraja, and Trichogramma evanescens Westwood in controlling pink bollworm (Pectinophora gossypiella Saund.). Five releases of each parasitoid were conducted in each season with a rate of 60,000 ♀♀/ release/ feddan. This rate was determined from laboratory and field estimations to the quality of the aforementioned wasps. The four Trichogramma species were significantly able to reduce pink bollworm infestation than control. Infestation of pink bollworm in green cotton bolls in the released area was below that of control by 87.00- 71.68% in the first season and 86.25-71.93% in the second one. Regarding the four species, T. embryophagum and T. bactrae were more effective in reducing pink bollworm infestation than the other two species.