Evaluation of indigenous the nucleopolyhedrovirus (NPV) of Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) in combination with chlorantraniliprole against Spodoptera species

Ghulam Sarwar,Mubasher Ahmad Malik,Muhammad Ahsin Ayub,Naeem Arshad Maan,Muhammad Farooq,Muhammad Rafiq Shahid

doi:10.1186/s41938-021-00403-8

Abstract

BackgroundThe armyworms, Spodoptera exigua (Hübner), and S. litura (Fabricius) (Lepidoptera: Noctuidae) are polyphagous pests of many cash crops. Heavy crop losses have been reported for the fruit and vegetable crops each year owing to the diverse impact on global economies. The present study was aimed to sort out a novel method of pest control using the insect’s own nucleopolyhedrosis virus (NPV) alone and in combination with a new chemistry insecticide chlorantraniliprole.ResultsIn the study, the effect of indigenous isolated nucleopolyhedrovirus (NPV) and the chemical insecticide (chlorantraniliprole) formulations against the 2nd and 4th larval instars of S. litura and S. exigua, collected from the different geographical region of Punjab (Pakistan) province, was evaluated. Three concentrations of the NPV isolate, sub-lethal (1 × 104, 6 × 104 POB ml−1), lethal (3 × 105 POB ml−1), and chlorantraniliprole 0.01 μl l−1, were applied alone and in combination against the 2nd and 4th larval instars of both pest species. The lethal concentration of NPV + chlorantraniliprole exhibited synergistic interaction and caused high larval mortality against both instars, while in all other combinations, additive effect was observed. Moreover, NPV + chlorantraniliprole at lethal concentration exhibited decreased pupation, adult emergence, and egg eclosion.ConclusionThe implications of using NPV alone and in combination with an insecticide are discussed briefly in this study.

Highlights

The armyworms, Spodoptera exigua (Hübner), and S. litura (Fabricius) (Lepidoptera: Noctuidae) are polyphagous pests of many cash crops
The S. litura multiple nucleopolyhedroviruses (SlM-nucleopolyhedrosis virus (NPV)) have been molecularly characterized, and their biological activity has been tested against S. litura populations in Pakistan (Ahmad et al 2018; Ali et al 2018; Ayyub et al 2019) and all over the world (Laarif et al 2011 and Kumar et al 2012a, 2012b)
Mortality of S. litura The 2nd instar larvae showed a 38.10% mortality rate when exposed to a sub-lethal concentration of chlorantraniliprole (0.01 ppm), while the larvae treated with NPV showed 34.02, 48.41, and Mortality of S. exigua

Summary

Introduction

The armyworms, Spodoptera exigua (Hübner), and S. litura (Fabricius) (Lepidoptera: Noctuidae) are polyphagous pests of many cash crops. Spodoptera exigua (Hübner) and S. litura (Fabricius) (Lepidoptera: Noctuidae) are native to Asia (Farahani et al 2012). Both attack more than 90 plant species. Baculoviruses consist of rod-shaped, dsDNA-occluded viruses that infect insect pests belonging to the orders Lepidoptera, Hymenoptera, and Diptera (Williams et al 2017). Due to their fast-killing nature and host specificity, some of these viruses have been used as commercial bioinsecticides (Sosa-Gómez 2017). The S. litura multiple nucleopolyhedroviruses (SlM-NPV) have been molecularly characterized, and their biological activity has been tested against S. litura populations in Pakistan (Ahmad et al 2018; Ali et al 2018; Ayyub et al 2019) and all over the world (Laarif et al 2011 and Kumar et al 2012a, 2012b)

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Discussion

Conclusion