COMSATS Institute of Information Technology, Pakistan
The aim of this investigation was to evaluate pest management potential of some medicinal plants, against different strains of Tribolium castaneum, Trogoderma granarium and Cryptolestes ferrugineus, the most common and major insect pests of stored grain. Essential oils extracted from Datura stramonium, Eucalyptus camaldulensis, Moringa oleifera and Nigella sativa with concentrations of 5, 10, 15 and 20% were applied on filter papers to make physical contact or to repel the insects under a constant temperature of 30 ± 2 °C and 65 ± 5% relative humidity. All essential oils exhibited considerable insecticidal and repellent activities against test insects. Among the essential oils, D. stramonium showed the highest toxicity, i.e. 32.26, 23.83 and 56.41% mortality and repellency 74.1, 73.9 and 80.2% against T. castaneum, T. granarium and C. ferrugineus, respectively. Concentration and exposure time significantly affected the mortality and repellency. Overall repellency in all treatments was found higher after 48hr as compared to 24 and 72hr. Bioactivities were observed in the order of D. stramonium > E. camaldulensis > N. sativa > M. oleifera. The results clearly advocate the use of essential oils as integrated pest management technique to protect grain during storage.