Free fatty acids from Momordica charantia L. flower surface waxes influencing attraction of Epilachna dodecastigma (Wied.) (Coleoptera: Coccinellidae)

Momordica charantia L. (Cucurbitaceae) is an important vegetable in Asia and Africa. Larvae and adults of Epilachna dodecastigma (Wied.) (Coleoptera: Coccinellidae) consume M. charantia leaves and flowers and reduces crop production. Currently, this pest is controlled by insecticides application. Hence, it is necessary to find out allelochemicals from flowers attracting the insect, which might be used for environment friendly pest management program. Therefore, free fatty acid profile from flowers was characterized and then proposed use of a synthetic blend of fatty acids for development of baited traps. Extraction, thin layer chromatography and gas chromatography-mass spectrometry of M. charantia flowers revealed 14 free fatty acids. The free fatty acids from flowers and synthetic blends of fatty acids mimicking different concentrations of free fatty acids attracted female E. dodecastigma between 50-400 mu g/mL concentrations in Y-shaped glass tube olfactometer bioassay. A synthetic blend of 112.61, 29.22, 45.23, 101.76 and 65.73 mu g/mL of palmitoleic, stearic, oleic, arachidic and docosanoic acids, respectively, was most attractive to the insect, and could be used as a trapping tool for pest management.