Status of parasitoids in direct seeded and transplanted rice

摘要

Nine rice varieties were sown in experimental plots of Faculty of Agriculture, Annamalai University, Chidambaram. To monitor the natural enemies population using yellow pan trap. The results showed that parasitoids belonging to family Braconidae weremaximum during the ripening stage at the transplanted rice variety CR Dhan 206 (5.00 Nos.) and these belonging to Ichneumonidae were maximum in the reproductive stage of the transplanted rice variety of CR Dhan 206 (3.66). The peak population of the Trichogramma was observed in the reproductive stage of the transplanted variety of CR Dhan 207 (4.33) and whereas highest Platygastridpopulation was recorded in the ripening stage of the direct-seeded rice variety of CR Dhan 200 (9.33). The population ofEulophid was maximum number in the reproductive stage of the transplanted rice variety of CR Dhan 200 (8.66). The population of parasitoids belonging to family Chalcididae was maximum during the reproductive stage of the transplanted rice variety of CR Dhan207 (3.33). The peak population of Pteromalidae was recorded in the reproductive stage of the transplanted rice variety of CR Dhan 200 (9.00). Among the rice varieties maximum number ofparasitoids was recorded from CR Dhan 203, whereas the minimum from CR Dhan 209. Because of the changing cultural practices the pest and natural enemy population dynamics need to be closely monitored to make suitable amendments in the rice IPMstrategies.