Fumigant toxicity of essential oils from four plant species on adult oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae)

Saw toothed grain beetle, Oryzaephilus surinamensis (L.)is one of the most important stored-products pests. In order to find reduced-risk methods for controlling stored-products pests, the fumigant toxicity of essential oils from four plant species, Mint, Mentha longifolia (L.) (Lamiaceae), Sagebrush, Artemisia aucheri (Boiss) (Asteraceae), Rosemary, Rosmarinus officinalis (L.) (Lamiaceae) and Myrtle, Myrtus communis (L.)(Myrtaceae) was investigated on adult saw toothed grain beetles. The research was conducted under laboratory conditions (at 30 ± 2°C and 60 ± 5% R.H. 24 h darkness). Essential oils had a significant effect on mortality of adults, and mortality increased with increasing concentration and exposure time. The LC50 value of mint essential oil 0.35 µl/l air calculated after 24 h exposure time was more toxic amongst the plant essential oils test. The LC50 value for rosemary, myrtle and sagebrush were 0.42, 0.50 and 0.99 µl/l air, respectively. The LT50 value calculated at the highest concentration of 0.74 µl/l air of mint essential oil was 16.4 h. Amongst the plant essential oils studied here mint had the highest potential insecticidal properties against this important economic pest.