The efficacy of five insecticides viz., malathion,phosalone, dichlorvos, Fenvalerate and phosphamidon at their recommended doses viz., 0.05%, 0.05%, 0.05, 0.01% and 0.03%, respectively, was studied against the insect pests of cauliflower for two consecutive crop seasons (1996 & 1997). The impact of these treatments on natural enemies was also assessed. Among the five insecticides tested, phosalone (0.05%), dichlorvos (0.05%) and fenvalerate (0.01%) were found effective in controlling the aphids infesting cauliflower without banning the bio-agents while the treatments showed poor performance against cabbage butterfly, diamond back moth and leaf miner. none2001 Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Ecology; Population dynamics; Pollution; Chemical pollution; Abiotic factors; Chemical factors; Land and freshwater zones; Oriental region; India Coccinellidae; Syrphidae; Population density; Fertilizer and pesticide pollution; Abundance effect; Fertilizers and pesticides; Manipur; Abundance, effect of exposure to insecticides Aphidiidae; Hemipteran hosts; Aphididae; Fertilizer and pesticide pollution; Prevalence effect; Fertilizers and pesticides; Insecticides; Manipur; Prevalence, effect of exposure to insecticides Aphididae (Aphidoidea); Hymenopteran parasites; Aphidiidae; Prevalence; Fertilizer and pesticide pollution; Fertilizers and pesticides; Insecticides; Manipur; Hymenopteran parasite prevalence, influence of exposure to insecticides