Component fatty acids from green mango fruit surface stimulate oviposition of the mango pulp weevil, Sternochetus frigidus (Fabr.)

Component fatty acids that influence oviposition of the mango pulp weevil (Sternochetus frigidus (Fabr.)) in bioassays were identified from the hexane extract of 70-d-old green Mangifera indica `Carabao' fruit peel by gas chromatography-mass spectrometry. Two fractions were found to stimulate oviposition. The fatty acids found common to both active Fractions 5 and 6 were 12:0, 14:0, 12-methyl-, 15:0, 14-methyl-, 17:0, 16-methyl-, 18:1(8) and 18:2(9,12). The fatty acid 18:3(9,12,15) was found only in Fraction 6. Both fractions had a wide range of activity, 0.01 to 0.05 mango fruit equivalents, resulting in 5.4 eggs laid per female average in a 24-h bioassay, twice the number of eggs laid in the control