Jute hairy caterpillar, Spilosoma (=Spilarctia) obliqua (Walker) (Arctiidae: Lepidoptera), is an irregular and polyphagous insect pest that occurs all over India. A severe natural viral epizootic was observed in the field population of S. obliqua in jute. The virus was characterized as Spilosoma obliqua nucleopolyhedrovirus (SpobNPV NBAIR1) based on morphological, biological, and molecular characterization. Under scanning and transmission electron microscopy (SEM and TEM), the occlusion bodies (OBs) of SpobNPV NBAIR1 appeared as both tetrahedral and triangular with the size ranged from 1.04-1.72 μm. The results on the bioassay studies revealed that the lowest LC50 value of 2.93 OBs/mm2 by leaf disc bioassay against the second instar S. obliqua showed its high virulence. The identity of SpobNPV was further confirmed by the amplification of polyhedrin gene (NCBI GenBank accession no. MK288145). Eleven species of lepidopteran insects, viz., Spodoptera litura, S. exigua, S. frugiperda, Helicoverpa armigera, Plutella xylostella, Amsacta albistriga, Maruca vitrata, Trichoplusia ni, Pieris brassicae, Agrotis ipsilon, and Bombyx mori, were not susceptible to the infection with SpobNPV NBAIR1. Field experiments on jute crop revealed 68.92, 78.59, and 93.16% reduction in larval population of S. obliqua at 3, 4, and 7 days post spray of SpobNPV NBAIR1 (1.5 × 1012 OBs/ha at 2 ml/l), respectively. The present study is a renewed effort in the management of S. obliqua by the new strain of SpobNPV NBAIR1.

中文翻译：

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斜长螺旋毛虫（SpobNPV）菌株NBAIR1的四面体和三角核多角体病毒的特征和野外评估

黄麻毛毛虫，螺旋螺（= Spilarctia）obliqua（Walker）（Arctiidae：Lepidoptera）是一种不规则的多食性虫害，遍及印度。在黄麻的S. obliqua野外种群中观察到严重的自然病毒流行病。根据形态，生物学和分子特征，该病毒的特征为斜长螺旋体核多角体病毒（SpobNPV NBAIR1）。在扫描和透射电镜下（SEM和TEM），SpobNPV NBAIR1的咬合体（OBs）呈四面体和三角形，大小在1.04-1.72μm之间。生物测定研究的结果表明，叶圆盘生物测定法对第二龄无性链球菌的最低LC50值为2.93 OBs / mm2，显示出其高毒力。通过多角体蛋白基因的扩增（NCBI GenBank登录号MK288145）进一步证实了SpobNPV的身份。鳞翅目昆虫的11种，即斜纹夜蛾，exigua，S。frugiperda，棉铃虫，小菜蛾，小菜蛾，Trichoplusia ni，Pieris brasicae，Agrotis ipsilon和Bombyx mori不易感。 SpobNPV NBAIR1感染。对黄麻作物的田间试验表明，在喷洒SpobNPV NBAIR1（2 ml / l时分别为1.5×1012 OBs / ha）后的3、4和7天，S。obliqua幼虫种群减少68.92、78.59和93.16％。本研究是通过新的SpobNPV NBAIR1菌株在斜纹酵母中的新尝试。frugiperda，Helicoverpa armigera，Plutella xylostella，Amsacta albistriga，Maruca vitrata，Trichoplusia ni，Piris brasicae，Agrotis ipsilon和Bombyx mori对SpobNPV NBAIR1均不敏感。对黄麻作物的田间试验表明，在喷洒SpobNPV NBAIR1（2 ml / l时分别为1.5×1012 OBs / ha）后的3、4和7天，S。obliqua幼虫种群减少68.92、78.59和93.16％。本研究是通过新的SpobNPV NBAIR1菌株在斜纹酵母中的新尝试。frugiperda，Helicoverpa armigera，Plutella xylostella，Amsacta albistriga，Maruca vitrata，Trichoplusia ni，Piris brasicae，Agrotis ipsilon和Bombyx mori对SpobNPV NBAIR1均不敏感。对黄麻作物的田间试验表明，在喷洒SpobNPV NBAIR1（2 ml / l时分别为1.5×1012 OBs / ha）后的3、4和7天，S。obliqua的幼虫种群减少了68.92、78.59和93.16％。本研究是通过新的SpobNPV NBAIR1菌株在斜纹酵母中的新尝试。SpobNPV NBAIR1喷洒后第3、4和7天分别倒水（1.5×1012 OBs / ha，2 ml / l）。本研究是通过新的SpobNPV NBAIR1菌株在斜纹酵母中的新尝试。SpobNPV NBAIR1喷洒后第3、4和7天分别倒水（1.5×1012 OBs / ha，2 ml / l）。本研究是通过新的SpobNPV NBAIR1菌株在斜纹酵母中的新尝试。