Evaluation of poison baits against tobacco caterpillar, Spodoptera litura (Lepidoptera: Noctuidae) in castor

Abstract

Laboratory and field experiments were conducted during 2014-2016 to find out the effective poison bait composition for the preference and efficacy against tobacco caterpillar, Spodoptera litura (Lepidoptera: Noctuidae) in castor. Free-choice test conducted to study the preference of fourth instar larvae of S. litura revealed that wheat bran with jaggery (10:1 ratio) recorded the highest attraction (16.7 to 25.3%) at 24-hrs after release followed by deoiled rice bran with jaggery (13.3 to 17.3%) and rice bran with jaggery (12.7 to 14.7%). No-choice test conducted to study the efficacy of insecticides in wheat bran with jaggery bait formulations against fourth instar larvae of S. litura resulted 90 to 97.5% mortality with chlorpyriphos 20EC and 75 to 92.5% mortality with novaluron 10EC at 48-hrs after treatment. Field experiments conducted to evaluate the efficacy of five poison baits revealed that wheat bran + sugarcane jaggery + chlorpyriphos 20EC bait was found effective and resulted in maximum larval mortality of 51.1 to 53.3% and 43.3 to 56.7% as compared to 45.6 to 50% and 42.2 to 52.2% mortality in standard check viz., rice bran + sugarcane jaggery + monocrotophos 36SC during kharif 2014-15 and 2015-16, respectively. The poison bait containing 50 kg wheat bran, 5 kg sugarcane jaggery and chlorpyriphos 20EC @ 1250 ml/ha can be opted for inclusion as component in the Integrated Pest Management system for the control of late instar larvae of S. litura in castor.