Evaluating the Antifeedant Effects of Andrographolide-based Formulations against Lampides boeticus L., under Laboratory Condition

Abstract

Aims: To evaluate the antifeedant activity of Lampides boeticus (Linnaeus,1767), larvae exposed to various concentrations of Andrographolide-based formulations under laboratory conditions. Study Design:  Completely Randomized Design Place and Duration of Study: Department of Entomology, College of Agriculture, Vellayani and NCESS, Kerala during 2019- 2023. Methodology: The experiment was conducted with 9 treatments and 4 replications, treatments included various concentrations (1,3,5 and 7%) of formulations A (Andrographolide (70%) + Neem oil (20%) + Triton X-100 (10%)) and B (Andrographolide (70%) + Pungam oil (20%) + Triton X-100 (10%)). To assess the impact of formulations in the feeding behaviour of freshly moulted third instar larvae of L.boeticus L., no choice bioassay method was used. Each Petri plate lined with moist filter paper, confined a single larva with the treated pods of each specific concentration. The weight of the food consumed by the larvae was recorded at an interval of 24 hours after treatment and calculated percent feeding, per cent feeding inhibition, antifeedant activity (protection over control) and preference index of L. boeticus L., larvae against the formulations. Results: The results revealed that 7% of formulation A exhibits the highest larval feeding inhibition (93.05%), followed by 7% of formulation B (87.81%). Both formulations at 5% concentrations also demonstrate significant antifeedant effects. Preference index values categorize 7% of formulations A and B as extremely antifeedant.  The findings highlight the efficacy of these formulations in inhibiting larval feeding, with potential applications in pest management strategies. Conclusion: The present findings have demonstrated the notable efficacy of formulations A and B, particularly at the 7% concentration, in significantly inhibiting larval feeding of L.boeticus L., and the reduction in larval feeding percentages, coupled with high antifeedant activity and feeding inhibition rates, highlights the potential of andrographolide based formulations as potent biopesticides.