Department of Entomology, Himachal Pradesh Krishi Vishvavidyalaya, Palampur-176 062, H.P. (India).
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.
