INSECTICIDAL ACTIVITY OF Peumus boldus Molina ESSENTIAL OIL AGAINST Sitophilus zeamais Motschulsky

In stored grains, the main agents diminishing production are insects, which can produce losses between 20% and 80% before harvest or under storage. The insecticidal properties of the essential oil of fresh leaves of Peumus boldus Molina against maize weevil (Sitophilus zeamais Motschulsky) adults were determined under laboratory conditions. The highest mortality (100%) was achieved at 4% concentration by contact with a treated glass surface. The same concentration in impregnated corn (Zea mays L.) grain, resulted in 98.7% mortality. Mortality by fumigant action at 6 h was 100% with 35 ^L oil in 0.15 L (air volume). Concentrations 1, 2 and 4% of essential oil produced 0% Fi adult emergence. At 10 d of residual effect, the 4% concentration reached 63.7% mortality. All treatments were repellent to adults of S. zeamais and corn grain germination was not affected by any treatment.