Environmentally Friendly Agent Against Fall Armyworm (Spodoptera frugiperda): Antifeedant Potency of Mentha spicata Aqueous Extracts

Abstract

The rising trends of insect resistance, coupled with escalating environmental pollution from synthetic pesticides, heighten the need for a more effective and, non-hazardous agents to control insect/pests. Different aqueous extracts of Mentha spicata were screened for their phytochemical constituents and their antifeedant activities against Spodoptera frugiperda. Screening of the different aqueous extracts of Mentha spicata obtained by cold maceration revealed the presence of phenolics and tannins. The concentration of phenols and tannins in the water, glycerine, and glycerine plus water (glycerine-water) extracts were significantly different (p < 0.05). Mentha spicata water extract had a greater antifeedant activity against Spodoptera frugiperda as compared to glycerine and glycerine-water (60:40, v/v) extracts at a concentration of 5g/100 mL. The estimated % antifeedant activity recorded were 97 as against 8.21 and 49.81, respectively. Aqueous neem seed water extracts gave an estimated % antifeedant activity of 93.07 and it served as a control. Saponins were absent in all extracts and only water extracts had alkaloids present. The simple, non-hazardous, and cost-saving extraction method demonstrated could be applied in both commercial and subsistent farming to counteract the damnable effects of Spodoptera frugiperda infestation.