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

• Journal of fish pathology
• /
• v.7 no.1
• /
• pp.1-5
• /
• 1994

Nuclear polyhedrosis virus was successfully infected the continuous Sf cell line. At 12hrs post-infectio(P.I), the cell lost the motility and the nuclei of the cells were hypertrophied. At 24hrs P.I, the cells were somewhat abnormal form and PIB formation was observed. At 48hrs, the PIBs formed in all cells. PIBs in the nuclei were released in the culture media at 72hrs P.I. By the observation of NPV morphogenesis by electron microscopy at 13hrs P. I, the virogenic stroma formed in the nucleus, and nucleocapsids formed. At 48hrs P.I, many nucleocapsids were bundled and then occluded in PIB, and PIBs were matured. PIB shapes were mostly tetragonal and a polyhedron was about $3{\sim}10{\mu}m$ in size. Virions were rod shape. nucleocapsids ranging in size $30{\sim}40{\times}300{\sim}400nm$.

• Korean Journal of Computational Design and Engineering
• /
• v.4 no.2
• /
• pp.87-99
• /
• 1999

We developed a Part Information Brokering System, namely PIBS, that can inter-link part suppliers and buyers using WWW(World Wide Web). The major contribution of this paper is that the system provides a 3D collaboration environment that enables multiple users to share the same workspace where they cooperatively manipulate part features in real time. PIBS carries out two major functions: one to maintain part data in a part library, and the other to provide the means for the clients to cooperate. An object-oriented database is used for the part library which stores apart information registered by part suppliers. VRML(Virtual Reality Modeling Language) the ISO standard for 3D visualization on WWW, is used to represent 3D part models. Several Java programs have been implemented to support synchronous and a synchronous communication of the 3D models. Once the users are interconnected through the system, a user's manipulation of part objects is transparently and instantaneously transmitted to the others. This means that all the participants can are the same view and movement of the 3D part models. Since the system is developed using a Java applet-server architecture, it requires no additional software other than standard web browser. The prototype system has been successfully implemented, and demonstrated its applicability to virtual 3D part information sharing.

• Korean journal of applied entomology
• /
• v.28 no.2
• /
• pp.82-87
• /
• 1989

Mass production of Spodoptera litura nuclear polyhedrosis virus (SINPV) was carried out on massively reared host insects. The yield of SINPV was maximal with $6.7{\;}\times{\;}10^9$ PIBs per larva on the 8th day post inoculation, when 5th instar larvae were inoculated with $1.1{\;}{\times}{\;}10^7$ PIBs per ml, and 2 g of artificial diet was sufficient for food consumption of a larva. The moribund larvae were more suitable for handling and mass production of virus than the completely dead larvae. The larvae, when treated with methoprene ($Manta^{\circledR}$), prolonged their larval period and consequently became bigger to result in higher yield(about 15%) of virus.

• Korean journal of applied entomology
• /
• v.30 no.3
• /
• pp.212-218
• /
• 1991

Pathogenicity of Spodoptera exigua nuclear polyhedrosis virus (SeMNPV) against the host insect and 8 species of lepidopterous insects and cross infection of baculoviruses to third instar of S. exigua larvae were studied to determine as a biocontrol agent for S. exigua. The median lethal concentrations($LC_{50}$)of the SeMNPV to egg mass was $2.855\times10^5$ PIBs/ml and higher than that to the larvae of S. exigua. Mortality of the SeMNPV in third ins tar larvae was more increased than that in first and fifth instar of S. exigua larvae by 1.16 and 4.11 times, respectively. The median lethal times($LT_{50}$) to $1.56\times10^6$ PIBs/ml was in the range of 4.25 to 5.04 days. Infectivity of the SeMNPV against eight species of lepidopterous insects was showed only in the host insect, S. exigua. Autographa cali/ornica MNPV, Mamestra barassicae MNPV, and Trichoplusia ni MNPV were cross-infected to third instar of S. exigua larvae among ten of baculoviruses tested.

• Korean journal of applied entomology
• /
• v.35 no.3
• /
• pp.228-231
• /
• 1996

To produce Spodoptera exigua nuclear polyhedrosis virus (SeNPV) using S. exigua larvae, the efficiency of the in vivo production was analysed by larval instar, inoculum and mortality. The results revealed that the mortality of 4th instar larvae inoculated with 1.OX 10' EIBs per ml was 86.7% and the yields of SeNPV was maximal, demonstrating that 4th instar larvae inoculated with 1 . 0l~o6 PIBs per ml were effective to mass production of SeNPV.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.2
• /
• pp.395-400
• /
• 2004

Choristoneura fumiferana (Cf-2Cl) insect cells were cultured and immobilized by using cellulosesulfate (NaCS) and polydiallyldimethylammoniumchloride (PDADMAC). A concentration of CfMNPV (Choristoneura fumiferana multiple-mucleopolyhedrovirus) and a Cf-2Cl cell density in the microspheres have been achieved at the densities of $1.57\times10^{10}$ PIBs/ml and $7.5\times10^7$ cells/ml, respectively. Additionally, MTT-test was used to measure the viable cell density in the microspheres, and the confidence of MIT-test was investigated before and after baculovirus infection in the immobilized cell culture.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.17 no.1
• /
• pp.125-129
• /
• 2008

The purpose of this study was to investigate the characteristics of Mamestra brassicae nucleopolyhedrovirus (MabrNPV)-K1 isolated in Korea. Polyhedra of MabrNPV-K1 showed irregular appearance in shape with the average diameter $1.8{\mu}m$. MabrNPV-K1 contained a number of nucleocapsids within a viral envelope embedded in polyhedron. The polyhedrin of MabrNPV-K1 was composed of single polypeptide with a M.W. of approximate 31 kDa which is identical to the commercialized MabrNPV, Mamestrin, as a biological control agent. The nucleotide and amino acid sequences within the coding region of MabrNPV-K1 polyhedrin shared 99.0% similarity with the polyhedrin gene from previous reported MabrNPVs. The median lethal concentrations ($LC_{50}$) of MabrNPV-K1 and Mamestrin to M. brassicae larvae were $3.9{\times}10^3$ PIBs/larva and $6.0{\times}10^4$ PIBs/larva, respectively. Mortality of the MabrNPV-K1 against to the third instars larvae was 15 times higher than that of the Mamestrin. The median lethal times ($LT_{50})$ of MabrNPV-K1 by the concentration of polyhedra were lower ($4.4{\sim}6.1$ days) than those of Mamestrin ($4.1{\sim}8.6$ days). These results suggest that a local strain MabrNPV-K1 has high pathogenicity to M. brassicae and may be useful for the development of biological control agent to control this.

• Korean Journal of Organic Agriculture
• /
• v.23 no.4
• /
• pp.797-811
• /
• 2015

This study was carried out to identify the control effect of entomopathogenic microagent against Spodoptera exigua on organic chinese cabbage. In laboratory condition, insecticidal activity of 4 commercial BT pesticides against S. exigua were lower than 10% against second instar S. exigua. The insecticidal activity of entomopathogenic nematode were 33.3%, 83.3% and 100% at the concentration of $1{\times}10^2$, $3{\times}10^2$, $1{\times}10^3nematodes/ml$, respectively. Mixture of BT and nematode showed growth inhibition against S. exigua larvae. S. exigua nucleopolyhedrovirus (SeNPV) of $10^5PIBs/ml$ showed more than 70% insecticial activity. The yield of SeNPV was increased as in higher initial inoculation concentration of NPV, food supply, and growth temperature increased. In greenhouse experiment, the control value of BT and nematode mixture treatment was higher than BT and nematode treatment alone against S. exigua. In treatment of $10^7PIBs/ml$ of SeNPV, S. exigua was controlled completely. In farm condition, mixture of microbial agent and organic agricultural material showed higher control value against lepidopteran pest including S. exigua than BT single treatment.

• Journal of Microbiology and Biotechnology
• /
• v.16 no.10
• /
• pp.1485-1490
• /
• 2006

In this study, comparative replicational properties of Hyphantria cunea nucleopolyhedrovirus (HycuNPV) in Lymantria dispar (IPLB-LdElta) and Spodoptera frugiperda (IPLB-Sf21) cell lines were investigated. Our microscopic observations showed that cytopathic effects (CPEs) in LdElta cells appeared 12 h later than those in Sf21 cells. Whereas polyhedral inclusion bodies (PIBs) formed at 48 h postinfection (p.i.) in LdElta cells, it formed at 36 h p.i. in Sf21 cells. Extracellular virus production determined according to the 50% tissue culture infective dose ($TCID_{50}$) method in LdElta cells started about 12 h later when compared with Sf21 cells. Titers of extracellular virus in LdElta and Sf21 cells were calculated as $1.77{\times}10^9$ plaque forming units (PFU)/ml and $5.6{\times}10^9PFU/ml$, respectively, at 72 h p.i. We also showed that viral DNA replication began at 12 h p.i. in both cell lines. Viral protein synthesis was determined by SDS-polyacrylamide gel electrophoresis (PAGE) and polyhedrin synthesis was observed at 12 h p.i. in both cell lines. The results indicate that while the synthesis of macromolecules is 12 h later and production of extracellular virus is almost 3-fold lower in LdElta cells compared with those in Sf21 cells, the LdElta cell line is still a productive cell line for infection of HycuNPV.