title: Occurrence and characterization of a tetrahedral nucleopolyhedrovirus from Spilarctia obliqua (Walker).
abstract: Spilarctia obliqua Walker (Lepidoptera: Arctiidae) is a polyphagous insect pest damaging pulses, oil seeds, cereals, vegetables and medicinal and aromatic plants in India. The pest also infests turmeric and ginger sporadically in Kerala. We observed an epizootic caused by a nucleopolyhedrovirus (NPV) in field populations of the insects in December 2013. The NPV was purified and characterized. The isolate was tetrahedral in shape and belonged to multicapsid NPV. The REN profile of the SpobNPV genome with Pst I, Xho I and HindIII enzymes showed a genome size of 99.1±3.9 kbp. Partialpolh, lef-8 and lef-9 gene sequences of the isolate showed a close relationship with HycuNPV and SpphNPV. Phylogram and K-2-P distances between similar isolates suggested inclusion of the present SpobNPV isolate to group I NPV. The biological activity of the isolate was tested under laboratory conditions against third instar larvae of S. obliqua and the LC50 was 4.37×10(3)OBs/ml occlusion bodies (OBs) per ml. The median survival time (ST50) was 181 h at a dose of 1×10(6)OBs/ml and 167 h at a dose of 1×10(8)OBs/ml. SpobNPV merits further field evaluation as a potential biological control agent of S. obliqua, a serious pest of many agriculturally important crops in the Oriental region.
authors.affiliation: Division of Crop Protection, ICAR - Indian Institute of Spices Research, Marikunnu P.O., Kozhikode 673 012, Kerala, India. Electronic address: senthilkumarcm@spices.res.in.
authors.forename: C M
authors.initials: CM
authors.lastname: Senthil Kumar
authors.affiliation: Division of Crop Protection, ICAR - Indian Institute of Spices Research, Marikunnu P.O., Kozhikode 673 012, Kerala, India.
authors.forename: T K
authors.initials: TK
authors.lastname: Jacob
authors.affiliation: Division of Crop Protection, ICAR - Indian Institute of Spices Research, Marikunnu P.O., Kozhikode 673 012, Kerala, India.
authors.forename: S
authors.initials: S
authors.lastname: Devasahayam
authors.affiliation: ICAR - Indian Institute of Spices Research, Regional Station, Appangala, Madikeri 571 201, Karnataka, India.
authors.forename: Sharon
authors.initials: S
authors.lastname: D'Silva
authors.affiliation: Division of Crop Protection, ICAR - Indian Institute of Spices Research, Marikunnu P.O., Kozhikode 673 012, Kerala, India.
authors.forename: J
authors.initials: J
authors.lastname: Jinsha
authors.affiliation: ICAR - Indian Institute of Spices Research, Regional Station, Appangala, Madikeri 571 201, Karnataka, India.
authors.forename: S
authors.initials: S
authors.lastname: Rajna
mesh_terms: D000818:Animals; D061046:Biological Control Agents; D016679:Genome, Viral; D007814:Larva / Q000821:virology; D046529:Microscopy, Electron, Transmission; D009036:Moths / Q000821:virology*; D019251:Nucleocapsid / Q000648:ultrastructure; D017924:Nucleopolyhedroviruses / Q000145:classification / Q000302:isolation & purification* / Q000648:ultrastructure; D010802:Phylogeny
chemical_list: D061046:Biological Control Agents
keywords: Biopesticide; Late expression factor gene; Nucleopolyhedrovirus; Polyhedrin gene; Spilarctia obliqua; Turmeric