Bio-efficacy of new insecticides against the management of leaf folder, Cnaphalocrocis medinalis (Guenee) (Lepidoptera: Pyralidae) in rice

Studies on the different chemicals evaluated for their bio-efficacy against rice leaf folder revealed that, acephate 75 SP @ 675 g a.i ha -1 (92.30 % reduction with 0.14 larvae/ hill) followed by chlorantaniliprole 18.5 SC @ 41.62 ml a.i. ha -1 (91.75 % reduction with 0.15 larvae/ hill), flubendiamide 20 WDG @ 36 g a.i. ha -1 (90.10 % reduction) and indoxacarb 15.8 EC @ 35.55 ml a.i. ha -1 (88.46 % reduction) were found significantly superior in reducing the population of leaf folder larvae.Among the insecticides evaluated against per cent leaf damage, the lowest leaf damage was recorded in acephate 75 SP @ 675 g a.i ha -1 (63.15 % reduction with 5.74 % leaf damage), flubendiamide 20 WDG @ 36 g a.i. ha -1 (62.19 % reduction with 5.89 % leaf damage), chlorantaniliprole 18.5 SC @ 41.62 ml a.i. ha -1 (61.36 % reduction) and indoxacarb 15.8 EC @ 35.55 ml a.i. ha -1 (60.78 % reduction); besides recorded higher grain and fodder yield compared to rest of the treatments.Acephate 75 SP @ 675 g a.i ha -1 was found to be the best insecticide in getting highest net profit and cost benefit ratio with lower leaf folder infestation (Rs. 64,264, 1: 2.79). Other insecticides such as indoxacarb 15.8 EC @ 35.55 ml a.i. ha -1 (Rs. 62,037, 1: 2.65), flubendiamide 20 WDG @ 36 g a.i. ha -1 (Rs. 62,307, 1: 2.64) chlorantaniliprole 18.5 SC @ 41.62 ml a.i. ha - 1 (Rs. 63,761, 1: 2.55), indoxacarb 14.5 SC @ 39.15 ml a.i. ha -1 (Rs. 54, 642, 1: 2.31) and spinosad 45 SC @ 48.60 ml a.i. ha -1 (55,103, 1: 2.28) were also recorded better cost benefit ratio and net profit.