Bio-efficacy of various insecticides against white grubs (Coleoptera: Scarabaeidae) infesting sugarcane

Abstract

The experiment was carried out to study the efficacy of various insecticides viz., Carbofuran 3G @ 750 g a.i./ha, Clothianidin 50WDG @ 120 g a.i./ha, Fipronil 0.3G @ 50 g a.i./ha, Thiamethoxam 25WG @ 80 g a.i./ha, Imidacloprid 70WG @ 300 g a.i./ha, Chlorantraniliprole 0.4 GR @100 g a.i./ha, Fipronil 40% + Imidacloprid 40% WG @ 300 g a.i./ha, Chlorpyrifos 10G @ 300 g a.i./ha and Emamectin benzoate 5SG @ 12.5 g a.i./ha against white grubs infesting sugarcane. All the treatments were found significantly effective over the control. Fipronil 40% + Imidacloprid 40% WG @ 300 g a.i./ha was found to be the most effective in per cent reduction over control i.e., 83.44 and 78.61% followed by Clothianidin 50WDG @ 120 g a.i./ha (81.49 and 76.75%) during the 2019–2020 and 2020–2021 cropping season, respectively. The treatment Emamectin benzoate 5SG applied @ 12.5 g a.i./ha was found to be less effective by recording 34.25 and 32.27% reduction of plant damage but significantly superior over control during both years. The highest sugarcane yield and cost benefit ratio was obtained in Fipronil 40% + imidacloprid 40% WG applied @ 300 g a.i./ha followed by Clothianidin 50WDG @ 120 g a.i./ha. Observations after application of insecticides revealed that, there was no record of any phyto-toxicity symptoms on sugarcane in all the treated plots. Experimental result revealed that Fipronil 40% + Imidacloprid 40% WG applied @ 300 g a.i./ha was effective for the management of white grub in sugarcane crop without causing any harm to natural enemies.