Volatile oil composition and insecticidal activity of some local plants against Sitophilus zeamais

Abstract

The essential oils from the leaves of Hyptis suaveolen, Thuja orientalis, Cymbopogon citratus, and Eucalyptus camaldunensis plants were obtained using hydrodistillation method. The oil composition were reviewed using literature and are found to have similar prominent compounds, although in different concentration. The insecticidal potential of the oils were carried out against grain pest, Sitophilus zeamais using adult mortality, adult emergence, and percentage reduction in adult emergence. The results obtained in adult mortality increases as the exposure time increases even at the lowest concentration. The four plants oil extract were able to evoked 100% mortality of adult Sitophilus zeamais at the rate of 0.1,0.2,0.3,0.4,0.5 and 1.0ml/20g of maize grains after 72 hours of post treatment. The results obtained from this study revealed that the oil extracts of these plants can be used as insecticides against S. zeamais. These plants are medicinal, biodegradable, readily available and poses no harm to man.