Insecticidal activity of Vitex doniana (Black plum) on Spodoptera littoralis (moth)

Abstract

Vitex doniana is a medium-sized deciduous tree of 8–18 m high, with a heavy rounded crown and a clear pole up to 5 m in height. The study evaluated the insecticidal efficacy of V. doniana extract on Spodoptera littoralis using bark and leaves. The plant parts were collected from Abubakar Tafawa Balewa University, Bauchi. Samples were left to dry by air under normal conditions in the laboratory for 2 weeks. The dried samples were ground into powder using a blender. The powder was then extracted using 350% ethanol by cold maceration. The culture of S. littoralis was maintained in the laboratory on cabbage and corn leaves for the insect to acclimatize to the environment. The phytochemicals found in the extract were alkaloids, glycosides, flavonoids, saponins, tannins, steroids, and terpenoids. The study revealed that the crude ethanolic extract of leaves at 400 mg concentration was more effective against the seventh larva stage than that of the bark at the same concentration with average mortality rate of 6.08%, compared to 4.08% for the bark. Hence, the use of V. doniana leaves as an insecticide for the control of
S. littoralis is safe and environmental friendly compared to the synthetic insecticides, which are
hazardous, and its residual effect is persistent in the environment.