| Abstrakt: |
In many Integrated Pest Management (IPM) programs, many essential oils were recommended to protect plants from insect's infestations and have few effects on nontarget organisms and the environment. Four essential oils (EOs): Ocimum basilicum, Peganum harmala, Anethum graveolens and Lavandula angustifolia were evaluated against two of the most important stored product insect pests, Callosobruchus maculatuc and C. chinensis infesting cowpea seeds during storage. The tested essential oils were obtained by steam distillation methods of dried plants. Effect of Contact toxicity, insecticidal of lethal concentrations, Oviposition deterrent activity, effect on germination and weight loss of seeds of tested oils were experimented on tested insects. The highest conc. 1% achieved (93, 80 and 77%) in the case of O. basilicum, P. harmala, A. graveolens, respectively in the case of C. maculatus. While in C. chinensis 1% conc. achieved, 90, 72 and 67% in the case of O. basilicum, A. graveolens and P. harmala, respectively. The LC50 of tested oils showed that the LC50 of O. basilicum was significantly decreased 4-fold more than lavender oil and O. basilicum is the best oil against C. maculatus and C. chinensis. Cowpea seeds treated with O. basilicum at high rate (1%) showed maximum prevention in oviposition i.e., 99% followed by A. graveolens causing (63 and 55%) prevention in the oviposition of C. maculatus and C. chinensis, respectively. Least weight loss was observed in O. basilicum and A. graveolens in the case of C. maculatus (4.44±0.47 and 8.13 ± 0.32) and C. chinensis (3.14±0.33 and 6.17 ± 0.12), respectively. O. basilicum treatment achieved the highest Feeding Deterrent Index (FDI) of 92.99 and 89.88% in the case of C. chinensis and C. maculatus, respectively. Least (FDI) was recorded in case of L. angustifolia (36.72 and 32.46%) in the case of C. chinensis and C. maculatus, respectively. Our results confirmed that O. basilicum essential oil had an obvious role in suppressing the activity of the tested insects. O. basilicum essential oil can be used in an integrated pest management program as green pesticide and can be effective alternative for chemical pesticides. [ABSTRACT FROM AUTHOR] |
