Ashok Varma

Field trials with cotesia flavipes cameron against sugarcane borers in sub tropical india

Cotesia flavipes Cameron (Hymenoptera : Braconidae), an important gregarious larval endoparasitoid of sugarcane borers, is widely distributed in different cane growing regions in India with its range of parasitisation from 4.0 to 21.6 per cent. Field trials were conducted on the releases of Cotesia flavipes Cameron (Indonesian strain) against sugarcane stalk (Chilo auricilius Dudg.) and internode (Chilo sacchariphagus indicus Kapur) borers in RBD and blocks trial at IISR Farm, Lucknow from July to November during 1992–93 to 1998–99 crop seasons. The field trials conducted on the releases of the parasitoid in RBD @800, 1600 and 2400 mated females /ha/ month split into four doses indicated reduction in the infestation of C. auricilius in all the parasitoid released treatments as compared to check. In the trials conducted in small blocks (54 X 70 m2) on the release of the parasitoid @1600 and 2000 mated females /ha/ month indicated a significant reduction in the infestation of C. s. indicus (28.4%) and C. auricilius (52.9 %) during 1993–94 and 1996–97, respectively. The large scale trials (54 X 180 m2) conducted during 1997–98 and 1998–99 on the releases of the parasitoid @2000 mated females /ha/ month split into four doses i.e. 500 mated females/ha at weekly interval from July to November indicated a reduction of 69.6 and 43.1 per cent, respectively, in stalk borer infestation in the month of October in parasitoid released block as compared to check.