The maize weevil ( Sitophilus zeamais Motschulsky) and the red flour
beetle ( Tribolium castaneum Herbst) are two key pests of
stored-grain products worldwide. The insecticidal activity of boldo (
Peumus boldus Molina) powder, liquid ethanolic and hexanic extracts
against S. zeamais and T. castaneum were evaluated under laboratory
conditions. The evaluated variables were mortality, emergence of adult
insects (F1), and grain weight loss. The experimental design was
completely randomized. The mortality in S. zeamais was 100% even at the
lowest powder concentration (0.5% w/w), whereas emergence of F1 adult
insects was 0% and grain weight loss was = 0.08%. For T. castaneum,
only 8 and 16% w/w powder concentrations reached 100% mortality. The
liquid ethanolic and hexanic extracts caused 100% mortality of S.
zeamais, whereas only the ethanolic extract reached this value for T.
castaneum. Therefore, the powder and the evaluated extracts of P.
boldus were toxic for S. zeamais and T. castaneum and are promising
against these and other stored-grain pests
