Abstract:
In an effort to find eco-friendly alternatives to synthetic pesticides in grain storage, residual contact toxicity and
repellence of Cupressus lusitanica and Eucalyptus saligna leaf essential oils were evaluated against adult Tribolium
castaneum, Acanthoscelides obtectus and Sitophilus zeamais. In bioassays, oil was applied at 0.00, 0.05, 0.10, 0.15
and 0.20% v/w to wheat and bean grains and stored for 30–120 days after which test insects were introduced
into sub-samples of treated grains. Both oils at 0.20% v/w and 120 days grain storage duration caused a mor-
tality of 5.0–65.0% in test insects whereas in the repellence bioassay, at same doses and grain storage duration
produced percent repellence values of 34–52.4% of test insects. Considering other pesticidal properties of C.
lusitanica and E. saligna oils, current results point oils as potential residual contact toxicants and repellents for
possible integration into insect pest management practices.
