Bio-efficacy of botanical soap formulations fortified with essential oils against Henosepilachna vigintioctopunctata (Fab.) (Coleoptera, Coccinellidae) and evaluation of its shelf life

Abstract

Experiments were conducted to evaluate the efficacy of botanical soap formulations against epilachna beetle, Epilachna vigintioctopunctata (Fab.) (Coleoptera, Coccinellidae), and their repellent effect and the shelf life. In the first experiment, neem oil+ citronella oil soap @2 per cent recorded the highest per cent mortality and was on par with treatments, pongamia+ basil oil soap @ 2 per cent, neem oil+ basil oil soap @ 2 per cent, and pongamia+ citronella oil soap @ 2 per cent after 24 hours after treatment. In the second experiment, neem oil+ citronella oil soap @ 2 per cent recorded maximum repellence (80%) and was on par with pongamia oil+ citronella soap @ 2 per cent (73.33%) and neem oil+ citronella soap @ 1 per cent (65%) after 30 minutes after treatment. In the third experiment, neem oil + citronella oil @ 2 per cent exhibited the highest mortality rates under both refrigerated and room conditions and statistically superior to all other treatments. The lowest per cent mortality was recorded for the control. The soap formulations stored under refrigerated conditions (for a period of three months), showed higher insecticidal efficacy than those stored at room conditions, revealing the effectiveness remained for three months.