BIOACTIVE CHARACTERIZATION AND EFFICACY OF NEEM SEED LOTION AGAINST STORED PRODUCT INSECTS OF MAIZE (ZEA MAYS L.), RICE (ORYZA SATIVA L.) AND COWPEA (VIGNA UNGUICULATA L. WALP)

Abstract

Insects pest of stored products are responsible for the significant losses of grain crops in storage and the best approach is the application of insecticides. Synthetic insecticides have immediate effects on the target insects; however, associated with adverse health implications. In view of this fact, there is a need for alternative to conventional chemicals. Thus, this study was conducted to assess the efficacy of the neem seed lotion against stored product insects; Sitophilus zeamais, Sitophilus oryzae, Rhyzoper thadominica, and Tribolium castaneum. Chemical compositions of neem seed were determined using HPLC analysis while evaluation of the bioactive chemical constituents from formulated neem seed lotions was done with six concentrations (100, 80, 60, 40 20 and 0% v/v) at Crop and Environmental Protection department, LAUTECH, Ogbomoso, Nigeria. and each treatment was arranged in complete randomized design with four replications. The results revealed different bioactive compounds and the major bioactive compounds from quantitative analysis is Azadirachtin A which is the real insecticidal active compound while qualitative analysis revealed Saponins, Glycosides, Steroids and Anthraquinones strongly present in the neem seed formulation. The tested neem seed lotion exhibited insecticidal action against the studied insects within 24 hours of exposure and response of the studied insects to neem seed lotions was the same and the efficacy of this bioinsecticide was not dose-dependent. Therefore, this neem seed lotion can be incorporated into the management program of stored product insects as an alternative to synthetic insecticides.