Evaluation of Nuclear Polyhedrosis Virus (NPV) and Emamectin Benzoate against Spodoptera litura (F.) (Lepidoptera: Noctuidae)

Abstract

Abstract The Oriental leaf worm moth, Spodoptera litura (F.) (Lepidoptera: Noctuidae), is among the most voracious insect pests in a variety of economically important crops, particularly cotton. It has developed resistance against conventional chemical insecticides. Therefore, it is vital to evaluate an integrated application of bio- and synthetic pesticide against this pest. Nuclear polyhedrosis virus (NPV) can be a potent alternative to control this pest. The present study was conducted to evaluate the efficacy of NPV and emamectin benzoate (Proclaim® 19EC) against three geographically distinct populations of S. litura in vitro conditions. Second and fourth larval instars were treated by three different concentrations of NPV (NPV-1 2 × 109, NPV-2 3 × 109, and NPV-3 4 × 109 POB ml−1) and emamectin benzoate (EB 0.1 ppm) alone and in combination. The results showed that the highest mortality rate (83.28%) was recorded for NPV-3 + EB, followed by NPV-2 + EB, NPV-1 + EB, EB, NPV-3, NPV-2, and NPV-3 at all the tests. Moreover, Faisalabad (FSD) population was found more susceptible, followed by Layyah (LY) and Multan (ML) populations. Reduction in pupation, adult emergence and egg eclosion was found directly related to the pathogenicity of the applied pathogens. The results of this study revealed that biorational control of S. litura with combined application of NPV + emamectin benzoate was an effective tool.

Keywords

• Nucleopolyhedrosis virus, Emamectin benzoate
• Spodoptera litura
• Efficacy