First record of a nucleopolyhedrovirus infecting brown-tail moth larvae, Euproctis chrysorrhoea (L.) (Lepidoptera: Lymantriidae) in India

Barkat Hussain,M Kannan,G Sivakumar,Abdul Rasheed War,Chandish R Ballal

doi:10.1186/s41938-019-0117-9

Abstract

Ladakh (Jammu and Kashmir) is the coldest arid region of India, where apricot is a major fruit grown across the region. In recent years, severe infestation by the defoliating caterpillar, brown-tail moth, Euproctis chrysorrhoea (L.) (Lepidoptera: Lymantriidae), on apricot trees has been reported in and around the Batalik sector. During field surveys, dead larvae of the brown-tail moth infected with a nucleopolyhedrovirus (NPV) were found. Electron microscopic studies revealed the typical baculovirus occlusion bodies (OBs) with polyhedral structures. Under a scanning electron microscope (SEM), the OBs of Euproctis NPV appeared to have crystalline structures of variable shapes and sizes which varied from 1.016 to 1.596 μm. Most of the OBs were tetrahedral and few were of hexagonal in shape. The transmission electron microscope (TEM) images of the OBs revealed the tetrahedral shape. The leaf disc bioassay showed the LC50 of 1 × 104 OBs/ml against second instar larvae of Euproctis chrysorrhoea. The 95% fiducial limits ranged from 1.416 to 2.887. This is the first report of NPV from the brown-tail moth in India from the Ladakh region. NPV being safe and environmentally friendly could be an ideal component for the integrated pest management (IPM) approach to controlling the pest.

Highlights

IntroductionThe outbreak of an invasive pest, the brown-tail moth, Euproctis chrysorrhoea (L.), in the Ladakh region is a bottleneck for fruit trade from this region (Tundup et al, 2016; Lamo, 2017; Bhagat, 2018)
Ladakh is the high-altitude cold desert region in Jammu and Kashmir and is one of the major producers of apricot in India
Collection and extraction of baculovirus The NPV was isolated from the dead larvae of E. chrysorrhoea, collected from apricot trees, in the Bioassay Median lethal concentration (LC50) of Euproctis NPV to second instar larvae was estimated by a leaf disc bioassay method (Magholi et al, 2014) with few modifications

Summary

Introduction

The outbreak of an invasive pest, the brown-tail moth, Euproctis chrysorrhoea (L.), in the Ladakh region is a bottleneck for fruit trade from this region (Tundup et al, 2016; Lamo, 2017; Bhagat, 2018). Raghuvanshi et al (2016) reported severe infestation by this defoliating insect on apricot in the Dah-Hanu belt of Ladakh. Defoliation by this pest leads to poor quality and unmarketable fruit and renders them unfit for human consumption and commercial uses. The brown-tail moth and its virus, Euproctis nucleopolyhedrovirus (Euptoctis NPV), are invasive to India. It has been reported in restricted places in China (You et al, 1983).

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