Chemical composition, insecticidal properties and repellent activity of essential oils of several plant species against Oryzaephilus surinamensis (L.)

Essential oils (EOs) of Rosmarinus officinalis, Lavandula vera Mill, Chillea wilhelmsii and Ferula gummosa were obtained by hydrodistillation, then analyzed using gas chromatography (GC/MS). The obtained oils showed considerable toxic against 1-7 days adults of sawtoothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae). In order to determine the insecticidal activity of EOs, mortality was monitored after 3, 6, 9, 12, 24, 36 and 48 h in fumigant respiratory and after 12, 24, 36 and 48 h in contact toxicity. Repellent activity was evaluated after one hour. Results showed that time of exposure, the method used to test the toxicity and concentration of EO, all were activity-determinant factors, and R. officinalis oil showed more contact and fumigant toxicity, while Ferula gummosa EO strongly affected O. surinamensis in a repellent method.