No abstract

Botanical pesticides are a new trend for pest management because they are an environmentally safe alternative for synthetic chemicals. The aim of this study was to investigate the insecticidal activity of desert date (Balanites aegyptiaca [L.] Delile) seed oils against the red flour beetle (Tribolium castaneum Herbst) and determine the oil chemical compounds by gas chromatography-mass spectrometry. Oils were extracted by chloroform, hexane, and ethanol, and they were tested on the pest by the film residue method at doses of 1.131, 0.566, 0.283, and 0.142 mg cm-2 after 12, 24, 36, and 48 h. Results showed that chloroform achieved a 100% mortality rate at 1.131 and 0.566 mg cm-2 after 12 and 36 h exposure, respectively. Meanwhile, the hexane extract caused a similar effect after 24 and 48 h at the same doses, respectively. The chloroform extract scored the lowest median lethal dose (LD50, 0.134 mg cm-2) against the pest after 48 h of exposure. This finding indicated that chloroform extract was the most toxic for T. castaneum compared with the other extracts. The results of the oil analysis revealed that (9Z,12Z)-octadeca-9,12-dienoic acid, hexadecanoic acid, (Z)-octadec-9-enoic acid, and (E)-octadec-6enoic acid were the main components, but the concentration differed from one extract to another. These results suggest that chloroform and hexane extracts have potent insecticidal activity and could be used in grain storage to control pests.

No abstract

No abstract

Application of botanical pesticides is a new trend in pest control nowadays as an environmentally safe alternative measures for synthetic chemicals. Hence, this study was aimed to analyze the phytochemical constituents of four medicinal Chinese plants, namely Lonicera maackii, Platycladus orientalis, Viburnum opulus, and Crataegus pinnatifida, and to investigate the insecticidal potentialities of leaves extracts of these plants against Tribolium castaneum. The research was carried out under laboratory conditions, at the Institute of Resources and Environmental Engineering, Shanxi University, China. Ethyl acetate, methanol and water extracts of the plant leaves were tested at different concentrations (5, 2.5, and 1.25% w/v). Yields of extracting materials, mortality and repellent effects were the important parameters evaluated. The phytochemical screening showed the presence of alkaloids, saponins, tannins, flavonoid, and terpenoids in C. pinnatifida, but the other plants contain some of these compounds. The highest ethyl acetate extract concentration (5%) of V. opulus and C. pinnatifida obtained the best mortality means (5.00±0.41 and 4.75±0.25a, respectively), compared to the other treatments, but without significant differences from the middle concentration (2.5%) of both extracts. In repellency test, L. maackii methanol achieved the highest repellency percentage (91.38%). The findings proved that ethyl acetate extract of V. opulus and C. pinnatifida are the best insecticidal treatment, whereas methanol extract of L. maackii is the best repellent effect, against T. castaneum. These three plants require additional studies to be assessed as a component in pest management of store pests.