Evaluation of the bio-efficacy of novel insecticides against the shoot and fruit borer Earias vitella (Fabricius) in okra

Abstract

Okra (Abelmoschus esculentus L.) is a nutritionally and economically important crop in India, but its productivity is severely constrained by the shoot and fruit borer, Earias vitella (Fabricius), which can cause yield losses exceeding 60%. The present field investigation was conducted during summer 2024 and summer2025 at ICAR-IIVR, Varanasi, to evaluate the bio-efficacy and economics of different insecticidal treatments against E. vitella. Eight treatments, including azadirachtin, quinalphos, novaluron, lambda cyhalothrin, and varying doses of fipronil, were tested in a randomized block design. Results revealed that all insecticides significantly reduced fruit infestation compared to the untreated control, with fipronil @ 4 ml/l (T6) showing the highest efficacy, reducing infestation to 2.96% and recording the maximum yield (126.37 q/ha). Fipronil @ 2 ml/l and 1 ml/l ranked second and third in effectiveness, while novaluron and lambda cyhalothrin provided moderate control. Economic analysis indicated that fipronil @ 1 ml/l achieved the highest cost-benefit ratio (1:23.56), followed by lambda cyhalothrin (1:20.04). Overall, fipronil, particularly at higher doses, proved most effective in minimizing borer damage and enhancing yield, while lower doses offered superior economic returns. The study underscores the potential of fipronil as a key component of integrated pest management strategies for sustainable okra cultivation.