author(s)
Arbind Roshan Khalkho, MK Chakravarty and SJ Prasanthi

abstract
Experiments on bio-efficacy of various insecticides i.e., Acephate 75% SP @ 1.35g/ l water (T₁), Fipronil 5% SC@ 1ml/ l water (T₂), Diafenthiuron 50% WP@ 0.2g/ l water (T₃), Dimethoate 30% EC@ 2ml/ l water (T₄), Imidacloprid 17.8% SL @ 0.3ml/ l water (T₅), Monocrotophos 36% SL @ 1.5ml/ l water (T₆) including untreated control were conducted with the linseed variety Neelum against bud fly (Dasyneura lini) during rabi 2014-2015 and 2015-2016. Only one spray was given at 50 per cent flowering of the crop during both the years. Results revealed that all the insecticides offered considerable suppression of infestation by bud fly when compared with the unprotected plots. Among various treatments, spraying of Imidacloprid@0.30ml/l and Fipronil @ 1.0ml/l recorded with minimum mean incidence (7.42% and 7.54%) of bud fly by giving 12.07 and 11.10 q/ha seed yield of linseed during both the seasons, respectively. Whereas, older conventional insecticides like Monocrotophos (13.41%) and Acephate (14.30%) were significantly inferior to the novel insecticides but are better than untreated control and hence proves the superiority of newer molecules over conventional insecticides.