Evaluation of release technology for Trichogramma chilonis Ishii in the management of cotton bollworms

Studies were carried out during 2003 and 2004 to find out the release technology of Trichogramma chilonis Ishii (weekly releases from July to October @ 1, 50, 000/ha) for the management of cotton bollworms. Releases as tricho-eard (100, 150 and 200 points/ha) were compared with adult releases. On the basis of incidence of bollworms among fruiting bodies (17,63 and 16.79 %), green bolls (26.87 and 14.14%), parasitization of Helicoverpa armigera (Hübner) eggs (17.41 and 19,64%) and seed cotton yield (8.24 and 9.26 q/ha). The releases as adult proved better. Releases at 200 points/ha was better than releases at 100 and 150 points/ha