The maize weevil (
Sitophilus zeamais Motschulsky) is one of most important pest of stored seeds worldwide, but its current
control method is based on the use of synthetic insecticides, usually leading to undesirable problems such as insecticide
residues on treated food, human intoxications, and insect resistance development. Therefore the search of friendly alternative
methods is required. The aim of this study was to assess, under laboratory conditions, the insecticidal properties of
Peumus boldus
Molina,
Laurelia sempervirens
(Ruiz & Pav.) Tul., and
Laureliopsis philippiana
(Looser) Schodde essential oils
against
S. zeamais. The phytochemical analysis of the three essential oils showed 1,8-cineole, safrole and methyleugenol
as the common components; all of them documented with insecticidal activity from essential oils from other plant species.
The highest toxicity (100% mortality) of these three oils acting as a contact insecticide was observed at 24 h exposure at
4% concentration. The estimated LC
50 values for
P. boldus,
L. sempervirens, and
L. philippiana were 0.37, 1.02, and 0.28
μL g
-1, respectively.
Peumus boldus exhibited the highest fumigant activity with 100% adult mortality at 30 μL oil L
-1 air.
At ≥ 0.5% (v/w) concentration, all essential oils showed repellent activity. These three essential oils showed a promissory
insecticidal activity against the maize weevil.
