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 (F
1), 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 F
1 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.
