• Korean Journal of Microbiology
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• v.9 no.2
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• pp.69-73
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• 1971

On June in 1970 the authors discovered a pathogenecity, cytoplasmic polyhedrosis virus, of the Smithia virus in the larvae of Liparis dispay L. appeared on quercus forest in Chung-Neung district and had carried out a experiment to detect the pathogenecity of Smithia virus through the inoculation of it into the larvase, such as Liparis dispay L. Hyphantrea cunea DRURY, and Dendrolinus spectabilis BUTLER. The results obtained were as follows ; 1) Death rate of L.dispay and D.spectabilis treated by 10$^{6}$ /ml cytoplasmic polyhedrosis virus of Smithis virus were 88.0% and 85.5% respectively, when the larvaes of these insects are big enough. But there were none of pathogenecity in case of Hyphantrea cunea DRURY. 20 Dead larvae caused by the injection of Smithia virus had begum to find out about on 10 days after inoculation. Miximum death rate of L. didpay and D. spectabilis appeared on 20-25days nad on 25-30days, respectively, after the incoulation. 3) In the cytoplasm of Mid-gut cylindrical cells of both of these insects, polyhedrosis, such s hexagonal (0.5-2.0-6.0 micron) were found out and in these insects, polyhedrosis, such as hexaginal (0.5-2.0-6.0 mivton) were found out and in case of D.spectabilis were a few polyhedrosis, such as tetragonal, trianglar polyhedrosis. 4) Diluted concentration of `0$^{6}$ /ml cytoplasmic polyhedrosis virus of Smithia virus were spread out in the field conditions. The corrected mortality was confirmed as about 87.8%.

• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.632-637
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• 2007

A cytoplasmic polyhedrosis virus (CPV) was isolated from the larvae of Thaumetopoea pityocampa and shown to cause an infection of midgut cells. This viral infection revealed several important diagnostic symptoms, including discoloration of the posterior midgut, reduced feeding, and extended development time of the larvae. The virus infection is lethal to Thaumetopoea pityocampa, and with the increasing doses kills the larvae within 4-5 days post infection. Electron microscopy studies showed typical cytoplasmic polyhedral inclusion bodies that are icosahedral, and ranged from 2.4 to $5.3{\mu}m$ in diameter. Electrophoretic analysis of the RNA genome showed that the virus has a genome composed of 10 equimolar RNA segments with the sizes of 3,907, 3,716, 3,628, 3,249, 2,726, 1,914, 1,815, 1,256, 1,058, and 899 bp, respectively. Based on morphology and nucleic acid analysis, this virus was named Thaumetopoea pityocampa cytoplasmic polyhedrosis virus (TpCPV), and belongs to the genus Cypovirus, family Reoviridae.

• International Journal of Industrial Entomology and Biomaterials
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• v.21 no.1
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• pp.117-125
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• 2010

The tropical tasar silkworms, Antheraea mylitta (D) produce famous silk 'Kosa' in central part of India. Due to outdoor rearing it became susceptible to viral infection including cytoplasmic polyhedrosis virus (CPV). The common mode of entry of cytoplasmic polyhedrosis virus is per os and cause gresserie disease to the larvae. Histopathological studies elucidated the insect CPV virus produces infective polyhedral inclusion bodies (PIBs) in the midgut cell cytoplasm of virus infected fifth instar larvae. The PIBs multiply enormously in the cytoplasm without invading the nucleus. Ultrastructural studies confirmed the pathological effects of CPV on in midgut cell cytoplasm. The multiplication of polyhedral inclusion bodies took place into the vacuoles and form virogenic stromata in the cytoplasm of cells. However, the encapsulations of polyhedral inclusion bodies into the polyhedrin protein occurred and polyhedra were released into the lumen. At the late stage of infection, cells showed the regressed cytoplasmic organelles with large vacuoles and elongated mitochondria. Hence, the horizontal transmission of CPV causing the midgut cells disintegration in the tasar silkworm, Antheraea mylitta (D) confirmed during infection.

• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.1
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• pp.69-72
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• 2005

Bleaching powder solution (1 to $5\%$), slaked lime solution (0.1 to $0.5\%$) and formalin (1 and $2\%$) were tested for their efficacy against cytoplasmic polyhedrosis virus and Nosema mylittansis spores to control virosis and pebrine respectively in tasar silkworm, Antheraea mylitta in indoor rearing condition. All the disinfectants tested were found effective in suppressing the infection of virosis and pebrine significantly. Complete inactivation of Antheraea mylitta cytoplasmic polyhedrosis virus (AmCPV) was recorded when treated with $4\%$ bleaching powder, $0.4\%$ slaked lime for 20 min and $2.0\%$ formalin for 30 min. Similarly treatments of $3.0\%$ bleaching powder solution for 20 min and $2.0\%$ formalin for 30 min were found effective in complete inactivation of N. mylittanis spores.

• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.2
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• pp.97-101
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• 2006

The efficacy of wood ash from Terminalia arjuna (arjun) and T. tomentosa (asan) has been tested against virosis of tasar silkworm, Antheraea. mylitta D. The Polyhedral Occlusion Bodies (POBs) of Cytoplasmic Polyhedrosis Virus of A. mylitta (AmCPV) were exposed to the aqueous solution (0.5 to 4%) of wood ash for 5 to 30 minutes. The treated suspension of POBs was orally inoculated once to tasar silkworm larvae after 24 hours of $1^{st}$ moult, and larvae reared in indoor on arjun leaves till spinning. The application of aqueous solution of wood ash has established its potential as antiviral agent against cytoplasmic polyhedrosis virus. Two percent aqueous solution of wood ash from arjun and asan dissolved the Polyhedral Occlusion Bodies (POBs) of cytoplasmic polyhedrosis virus of tasar silkworm and inactivated the virions within a short period of 20 to 30 minutes. In vivo efficacy of aqueous solution of wood ash resulted in reduction of larval mortality due to virosis. The mortality was reduced to $2.56{\pm}0.21\;and\;3.03{\pm}0.32%$ when treatment of 2.0% solution of wood ash of arjun and asan respectively were applied for 20 minutes, compared to inoculated control $(92.18{\pm}7.52%)$. No mortality was recorded when treatment of 2.5% solution of wood ash of arjun and asan were applied for 10 minutes or more.

• Korean Journal of Microbiology
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• v.8 no.1
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• pp.21-34
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• 1970

This experiment was undertaken to examine the injurious environment conditions for occuring of the virus disease, grasserie and cytoplasmic polyhedrosis in rearing of silk worms, to observe of cytoplsamic polyhedrosis diseased silkworms with histological preparation and to define the virus origin on the gattine and the disease of shrinked form after moulting (Okichijimi). The results obtained are as follows. 1) The grasserie in spring season rearing was remarkably infected in highly percent with 20.1 % in high temperature condition during 3rd to 4th instar, the high temperature during 1st to 2nd instar and 5th instar in 16.5% and 16.3%, respectively. In the fall season rearing, the disease was infected by the feeding of soft leaves plot in 5.3% and 4.8%, respectively with significant difference in 5% level, accordingly, it was thought to the nutritional condition is a factor in occuring of the disease. 2) In spring season rearing, the number ofl infected silk worms of cytoplasmic polyhedrosis was increased in the high temperautre and high humidity conditions, and in fall season rearing, order of the low temperature and high humidity plot, first feeding plot and feeded with hard leaves plot were found insome high infected ratio of the disease than control plot. 3) The occuring of cytoplasmic polyhedrosis was observed even in control rearing plot with the examining of anatomical and histological preparation in spring and fall. 4) It was found that the high diseased ratio of the gattine and disease of shrinked form after moulting in 21.8% of control and 93.2% in feeded with inocylated plot in the biosassay of inoculum. It was defined as a virus flacherie acoording to the Danaka and Shimizu's examine method.

• Korean journal of applied entomology
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• v.30 no.3
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• pp.219-226
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• 1991

A cytoplasmic polyhedrosis virus isolated from the oriental tobacco budworm, Heliothis assulta (HaCPV), was studied on morphology of the polyhedron and virus particles, analysis of viral protein and nucleic acid, and bioassay of the HaCPV to determine the feasibility of application as a microbial control agent. The shape of polyhedron was hexagonal ranging 0.5-3.7 ${\mu}m$ and the virus particles were icosahedral outline measured 55 nm in diameter. Polyhedral protein was composed of a major polypetide of 24.3 Kd and 5 minor components and virus particle had seven polypeptides ranging in 28.0 Kd-133. 6 Kd by the SDS-P AGE. The genome of virus was segmented with 10 double stranded RNA in the total mol. wt. of 18.08 Md ranging in 0.65 Md -2.79 Md. The $LC_{50}$ values of the HaCPV to the 3rd instar of H. assulta larvae were calculated to $2.895{\times}10^5PIBs/ml$. The $LT_{50}$ values in the concentration of $5.0{\times}10^{6}PIBs/ml$ was 16.4 days.

• Journal of Sericultural and Entomological Science
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• v.18 no.2
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• pp.83-88
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• 1976

A study was made on the interstrain difference in dose-infection response and induction response of silkworm to the two strains of cytoplasmic polyhedrosis virus to obtain some informations on screening the leading strains. Comparison of dose-infection responses of larvae following the inoculation of the inclusion body of cytoplasmic polyhedrosis virus revealed that there is no significance in the resistance to dose-infection and any of strains were more resistant at advanced stage(4th instar) than younger stage(2nd instar). In the pathogenicity between cytoplasmic polyhedrosis virus with hexagonal and tetragonal outline, the hexagonal polyhedra showed higher pathogenicity than the tetragonal polyhedra. However, the averages of $LC_{50}$ of cytoplasmic polyhedrosis virus with hexagonal outline to larvae of parental inbred line were 6.12${\times}$10$\^$6//$m\ell$ at 2nd instar and 1.57${\times}$10$\^$7//$m\ell$ at 4th instar in spring and those to their hybrids were 1.28${\times}$10$\^$6//$m\ell$ at 2nd ins tar and 4.99${\times}$10$\^$6//$m\ell$ at 4th ins tar in autumn. Meanwhile the $LC_{50}$ averages of tetragonal polyhedra. to larvae of parental inbred line were 2.06${\times}$10$\^$7//$m\ell$ at 2nd instar and 5.67${\times}$10$\^$7//$m\ell$ at 4th instar in spring and those to their hybrids were 9.84${\times}$10$\^$6//$m\ell$ at 2nd instar and 3.86${\times}$10$\^$7//$m\ell$ at 4th instar in autumn, respectively. In comparison of induction response of silkworm larvae to inoculation of tetragonal polyhedra of cytoplasmic polyhedrosis virus, the induction rate of hexagonal polyhedra was remarkably higher in the treatment of inoculation at 2nd instar than at 4th instar and at the concentration of 1.3${\times}$10$\^$6//$m\ell$ than at any others. Most of induction showed a mixed infection with hexagonal and tetragonal polyhedra of cytoplasmic polyhedrosis virus.

• Journal of Sericultural and Entomological Science
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• v.16 no.1
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• pp.85-92
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• 1974

Many of studies on the transovarial transmission of occult virus and their activation due to various stresses such as cold or heat treatment, chemical feeding, and nutritional deficiency, etc., in the silkworm, Bombyx mori L. have been made, but any attempts have been not made to control virus diseases by detection of the occult virus-carried moths in the production of silkworm egg of hybrids, because of difficulty to detect occult virus in any stage. Therefore, it may be worth while to disclose whether a sublethal infection of the moths from which active virus are detectable, has the same level of induction rate as that of occult virus activation, thus to apply its results for the reduction of the occurence of virus diseases in silkworm rearing. For these purposes, the following experiment was conducted as one of preliminary steps. In this study, investigations on the generation-to-generation transmission of occult virus and a sublethal infection, and the role of chromosomal gene of the host, Jam 103 and Jam 104 in the Previous generation, and Jam 103 x Jam 103 and Jam 104 f Jam 104 in the next generation were made for the induction of virus diseases due to the transmitted virus. The frequency of cytoplasmic polyhedrosis due to the induction in the F$_1$ generation was markedly higher in the cross-batches, male$\times$female and male$\times$female in which inoculated individuals were used as fem ale parents than in the cross-batches, male$\times$female and male$\times$female in which virus has been not inoculated or inoculated only to male in the previous generation. The tendency of increasing rate was observed in any treatments; such as the inoculations of cytoplasmic polyhedrosis virus (10$\^$5/, 10$\^$6/ 10$\^$7, and 10$\^$8//ml ill different concentration of inocula) , cold-treatment (5$^{\circ}C$, 12hrs or 24hrs), and formalin-feeding treatment (2％ or 3％). The shape of polyhedra (tetragonal in outline) examined in the F, larvae was identified as that of the inoculated polyhedra with partial application of immunofluorescent techniques. These results suggests that the cytoplasmic polyhedrosis virus in B. meri L. are transmitted to the next generation through the egg, apparently in the occult state. And the experimental results of various cross-batches revealed the egg cytoplasm plays an important part i the transmission of the occult virus of the cytoplasmic polyhedrosis virus,

• BMB Reports
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• v.39 no.4
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• pp.412-417
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• 2006

We examined the intracellular localization of NS5 protein of Dendrolimus punctatus cytoplasmic polyhedrosis virus (DpCPV) by expressing NS5-GFP fusion protein and proteins from deletion mutants of NS5 in baculovirus recombinant infected insect Spodoptera frugiperda (Sf-9) cells. It was found that the NS5 protein was present at the plasma membrane of the cells, and that the N-terminal portion of the protein played a key role in the localization. A transmembrane region was identified to be present in the N-terminal portion of the protein, and the detailed transmembrane domain (SQIHMVWVKSGLVFF, 57-71aa) of N-terminal portion of NS5 was further determined, which was accorded with the predicted results, these findings suggested that NS5 might have an important function in viral life cycle.