INSECTICIDAL, REPELLENT AND ANTIFEEDING ACTIVITY OF POWDER AND ESSENTIAL OIL OF Schinus molle L. FRUITS AGAINST Sitophilus zeamais (Motschulsky)

Abstract

The pepper tree (Schinus molle L.) has secondary metabolites with insecticidal activity. The objective of this study was to assess under laboratory conditions the insecticidal and insectistatic activity of fruit powder and essential oil of S. molle against Sitophilus zeamais. In contact toxicity bioassays, the highest mortality was observed with essential oil at a concentration of 8.0%, recording 96.3% of dead insects with an LC50 of 3.82 mL essential oil 100 g-1 maize (3.82%). Powder at the same concentration showed a 63.8 % of mortality with an LC50 of 7.95 g powder 100 g-1 maize (7.95%). None of the treatments affected germination or grain weight loss. The essential oil at a concentration of 8.0% caused a complete inhibition of F1, resulting in 0% of adult insects. All treatments had repellent effects. The highest antifeeding effect observed with the essential oil was recorded at a concentration of 16.0% with a 72.2% of inhibition. It was concluded that both powder and essential oil of S. molle show contact insecticidal toxicity as well as repellent and antifeeding effects against S. zeamais.