In vitro determination of LD50 for AgriX365 on corn strain of Spodoptera frugiperda

Abstract

Fall armyworm, Spodoptera frugiperda, is currently a major and invasive pest that is threatening global maize production and food security especially in sub–Saharan Africa. Its tolerance to several available synthetic pesticides has led to research into novel pest management strategies. An in vitro laboratory bioassay was conducted at Bindura University of Science Education to determine the LD50 for AgriX365, a botanical pesticide, in a complete randomised design. There was a relative dose-dependent response in mortality rates of S. frugiperda from 0.5ml/L to 2ml/L of AgriX365. The logistic function Probit, P, calculation indicated an LD50 =1.25ml/L (1250 ppm); y=0.5998x+4.2749; R2=0.9979) of the standard or recommended field rate for AgriX365. There was a high significant difference between mean per cent mortality between treated S. frugiperda larvae and the untreated ones (p