Effect of some synthetic pyrethroids on leaf miner, Chromatomyia horticola (Goureau) infesting rapeseed

Efficacy of synthetic pyrethroids was evaluated in the field against the leaf miner, Chromatomyia horticola (Goureau), infesting rapeseed, Brassica campestris var. brown sarson (BSH-I) at Palampur (H.P.) for two years (1989–90 and 1991–92). Decamethrin 0.008% sprayed once during the second week of February was the most effective insecticide followed by fenvalerate 0.02% and cypermethrin 0.01%, 7 days after foliar application. The per cent leaf miner infestation in decamethrin treated plots was 2.1 as against 29.67 in control. Endosulfan (0.07%) was least effective, the infestation being 12.75%. The efficacy was quite comparable with the recommended insecticides, dimethoate (0.03%) and methyl demeton (0.025%), even 14 days after spraying.