Insecticidal Activities of Aromatic Plant Extracts against Four Agricultural Insects

The insecticidal activities of 30 aromatic plant extracts against four insect pests were examined by direct contact application. Against Nilaparvata lugens female adults, Myzus persicae female adults, and Plutella xylostella larvae, at 5,000 ppm, >90% mortality was achieved in the methanol extracts of the rhizomes from Cnidium officinale, Acorus gramineus, Acorus calamus var. angustatus and Curcuma Ionga, the whole plant from Agastache rugosa, the fruits from Illicium verum and Piper nigrum, and the flower bud from Eugenia caryophyllata as well as Cinnamomum camphora steam distillate. Against Spodoptera litura larvae, all test plant extracts were ineffective. The plants described merit further study as potential insect-control agents against insect pests.