Abstract:
Fall armyworm (Spodoptera frugiperda, J.E. Smith) is a pest with devasting effects on maize. A laboratory biassay was conducted to analyse the
phytochemicals and determine the efficacy of M. spicata and R. officinalis extracts on FAW. Treatments were laid out in a Completely Randomized Design
(CRD) with 3 replications. The factors included solvent [Methanol (Me), dichloromethane (DCM), distilled water (Di)] and the plant species (M. spicata and
R. officinalis). Coragen SC 200 (Co) and Distilled water (Di) were the positive and negative controls, respectively. FAW rearing, plant extract preparation
and phytochemical screening were done using standard procedure. Data collection and analysis was done using standard procedures. The extract yield was
highest for R. officinalis regardless of the solvent used. Me-R. officinalis and Di-M. spicata extracts yielded the highest. Saponins, glycosides, alkaloid,
flavonoids and tannins. Flavonoid contents were 7.9036 mg/mL and 6.0073 ± 0.6117 mg/mL in methanolic extract of M. spicata and R. officinalis,
respectively. M. spicatha and R. officinalis extracts caused 100% mortality to 3rd instar larvae. Based on the findings, both M. spicata and R. officinalis have
several secondary metabolites that confer insecticidal activity of the plants against FAW, hence should be evaluated under field conditions.
