Efficacy of Some Eco-friendly Insecticides against Insect Pests of Sikkim Mandarin Nursery

Six newer eco-friendly insecticides viz., Beauveria bassiana (Biopower) @ 7 g/L, Verticillium lecanii (Verticel) (5 g/L), Bacillus thuringiencis (Delfin 3G) 2 g/L, Multineem 3 ml/L, Petroleum Agro-spray (Servo) 7 ml/L, and Nimbicidine 3 ml/L along with two checks (one conventional insecticide i.e. monocrotophos along with other untreated check) were evaluated against insect pests of Sikkim Mandarin nursery during 2008. All the insecticides were significantly superior over untreated check. Among the treatments, monocrotophos 36 WSC 1 ml/L was observed to provide maximum reduction of insect pests at 7 d and 14 d after sprays. Though biopesticides showed inferior result in comparison to check monocrotophos but among the biopesticides Bacillus thuringiencis (Delfin 3G) 2 g/L was found most effective to control lemon butter fly and leaf roller while Petroleum Agro-spray (Servo) 7 ml/L was found effective against aphids and leaf miner.