A large number of plant essential oils have been used against diverse insect pests since they, unlike conventional pesticides,
present no risk to humans and the environment. This study was conducted to determine the toxicity of
Azilia eryngioides
(Pau) Hedge et Lamond (Apiaceae) essential oil against 1- to 7-d-old
Sitophilus granarius
(L.) (Curculionidae) and
Tribolium
castaneum
(Herbst) (Tenebrionidae) adults. The essential oil was obtained from aerial parts of the plant using a Clevenger
apparatus and analyzed by gas chromatography and mass spectrometry. The major constituents of the oil were α-Pinene and
bornyl acetate. Fumigation bioassays revealed that
A. eryngioides oil had a strong insecticidal activity on adult test insects
that were exposed to 37.03, 74.07, 111.11, and 148.14
μL L
-1 to estimate mean lethal time (LT
50) values. Mortality increased
as concentration and exposure time increased, and reached 100% at the 39-h exposure time and concentrations higher than
111.11 μL L
-1. Another experiment was designed to determine the mean lethal concentration at the 24-h exposure time
(LC
50)-, and these values indicated that
S. granarius was more susceptible than
T. castaneum. It can be concluded that the
essential oil of
A. eryngioides has potential against two stored-product pests,
S. granarius and
T. castaneum.
