Efficacy of Some Multi-Active Insecticide Formulation in Control of the Invasive Fall Armyworm (Spodoptera frugiperda, J. E. Smith)

Abstract

The use of synthetic insecticides remains a reliable tool for managing fall armyworm (FAW), Spodoptera frugiperda (J.E Smith) in Ghana. Studies were conducted to evaluate the laboratory toxicity and field efficacy of nine multi-active insecticides formulations for FAW management in maize. The insecticides evaluated were Ema star (Emamectin Benzoate + Acetamiprid), Dean (Emamectin Benzoate + Imidacloprid), Attack (Emamectin Benzoate + Nonhazardous Ingredient), Pyrinex quick (Chlorpyrifos + Deltamethrin), Galil (Imidacloprid + Bifenthrin), Adepa (Ethyl Palmitateethyl Oleate), Normax (Teflebenzuron + Alphacypermethrin), K-optimal (Lambda-Cyhalothrin + Acetamiprid) and Neemazal (Azadirachtin). Mortality of FAW larvae exposed to each formulation for 12– 96 hr was assessed using the completely randomized design. FAW larva abundance and damage incidence, and their impact on maize yield were evaluated using the randomized complete block design with each insecticide’s treatment replicated four times. The results showed that maize plants treated with Ema star or Dean recorded the highest (100%) larval mortality, while Galil, Neemazal and Normax treatments recorded the lowest (< 50%). Similarly, Ema star treated maize had a significantly lowest FAW infestation in the field. In terms of grain yield, maize plants treated with Emastar or Dean had the highest yield, and this was 3-fold higher than that of the Galil, Normax, treatments. Generally, spraying of Ema star or Dean formulations at recommended rates led to significant reductuion in FAW infestation in the field and maximum grain yield in maize.

Keywords: Larval mortality, Spodoptera frugiperda, insecticide toxicity, maize yield.