Evaluation for Feeding Deterrents Against <i>Sitophilus zeamais</i> (Motsch.) from <i>Tithonia diversifolia</i> (Hemsl.) A. Gray

Using bioactivity-guided isolation of bioactive compounds; deacetylviguiestenin, 4-O-caffeoyl-2-methyloxirane-2-carboxylic acid and sandaracopimaradiene-1α,9α-diol were obtained from Tithonia diversifolia (Hemsl.) A. Gray leaves identified using spectroscopic methods. Their feeding deterrence activity against Sitophilus zeamais (Motsch.) including those methanol crude extract, fractions, the essential oil was determined. Results showed that T. could not show significant anti-feedant at a dose ˂0.29 μL/mg flour disks. The solvent some fractions isolated compounds, however, demonstrated S. zeamais. index 81.19 ± 5.94% 0.1% w/w (1 mg/g food) compared to 97.45 0.43% for neemazal extract (10% azadirachtin) (positive control) 10%w/w (100 food). EC50 deacetylviguiestin, azadirachtin (commercial antifeedant) 22140.23 9103.29, 3654.28 2715.09 14.59 5.59 ppm respectively. Although these compounds less azadirachtin, their are valuable alternatives.