FEEDING DETERRENCE INDEX OF Momordica cymbalaria FENZL EX HOOK AGAINST COMMON CUT WORM, Spodoptera litura FABRICIUS

Abstract

Plant secondary metabolites exhibit a wide range of biological activity and may act as feeding and oviposition deterrents, repellents, fumigants, and behavior modifiers. Fruits and tubers of Momordica cymbalaria Hook (Fenzl.) possess anti-ovulatory and abortifacient properties that could be exploited in the management of insect pests. Hence, the feeding deterrent activity of M. cymbalaria leaf, peel (fruit skin), seed and tuber solvent extract against Spodoptera litura Fabr. was studied. Different concentrations of acetone extract of leaf from 0.3% to 0.8%, performed better in deterring S. litura larval feeding. Peel acetone extract showed a strong feeding deterrence (94.83% leaf area protection over the absolute control) at 0.9% concentration followed by medium deterrence at 0.8, 0.7, and 0.6% concentrations (85.62, 77.90, and 67.08 % protection respectively). The hexane seed extract was comparatively oilier and had a distinct rancid smell noticeable in the higher concentrations (0.8, 0.9, and 1%). Tubers did not exhibit any significant leaf area protection below 0.2% concentration. However, 1% tuber acetone extract showed 99.36 percent protection. The effective concentrations of leaf acetone extract for 50 and 95% deterrence were 0.27and 0.84 percent respectively. The effective concentrations of other plant parts were ranked as follows; Seeds>Peels>Tubers.