Nuclear Polyhedrosis Virus Strain Research Articles

Evaluating a newer nuclear polyhedrosis virus strain against the cotton moth Helicoverpa armigera on soybean (Glycine max)

Soybean is one of the economically significant crops in the world and is cultivated over a large area in Krasnodar Krai (Russia). In recent years, the harmfulness of the cotton moth Helicoverpa armigera Hubner (Lepidoptera: Noctuidae) has significantly increased for soybeans. The use of chemical insecticides leads to formation of resistance which can be prevented by bioinsecticides based on entomopathogenic baculoviruses. The aim of this research was to compare the biological efficacy of the Russian strains of the nuclear polyhedrosis virus (NPV) of cotton moth (CM) and the viral biological product Helicovex CK (Switzerland) and was conducted during 2020–2021. The treatment of the phytophage caterpillars and the comparison of the productivity of experimental strains, determined by the number of polyhedra formed per caterpillar were carried out under laboratory and field conditions. The experiments showed that the efficiency of the strain NPV CM M isolated from the caterpillars of the cotton moth selected on the tomato crops of the Federal Research Center of Biological Plant Protection in the laboratory and field did not significantly differ from the efficacy of the biological product Helicovex CK and amounted to 84.3–92.4%. In addition, the strain NPV CM M was distinguished by higher productivity and greater adaptability to storage in dried form than the strains NPV CM - 17 and NPV CM - 18. The productivity of the strain NPV CM M was 2.4–2.8 x 1010 polyhedra per one caterpillar, and the efficacy after one year of storage was 55.0%. The conducted studies revealed the possibility and prospects of using the Krasnodar strain.

Isolation and particle characterization of different strains of BmNPV isolated from south Indian region

Grasserie is a deadly viral disease which turns a clean creamy white silkworm into zombie worm. The nuclear polyhedrosis of B. mori caused by Nuclear Polyhedrosis Virus strain Bm (BmNPV) showing jaundice-like symptoms is collectively referred to as polyhedrosis. This DNA virus multiplies only in the nucleus of the host cells forming its complete structure in the host cell. The drawback of this disease is huge amount of crop loss. And to avoid this, the only way is prevention or the use of hazardous chemicals. To avoid all these, finding a new natural way is necessary. Before we think of controlling the virus, one should understand the detail characters of BmNPV. Light scattering is a fundamental analytical technique for the characterization of particulate materials and is most commonly applied to colloidal systems, nanoparticles and acromolecules in solution or dispersion to determine particle size and zeta Potential. This examination mainly focused on size and surface charge determination using SZ-100 nanoparticle series instrument. Further, the average OB size was found to be 150.7 nm, 138.8 nm, 143.8 nm, 140.0 nm and 140.5 nm in diameter for HRH, HSR, KNK, MSI and VKK BmNPV strain respectively. The zeta potential is often measured as a function of pH or other change in the chemistry to help formulators create new products with a long shelf life. The zeta-potentials of isolates were found to be more of negative because of the presence of PEP with the charge of - 29.0 mV, -35.4 mV, -45.0 mV, -28.1 mV and -23.5 mV for HRH, HSR, KNK, MSI and VKK BmNPV strain respectively. Thus, by exposing, these aspects may help to deduce in detail structural characteristics of different south Indian strains of BmNPV.

Virin HSK and Helicovex SK – efficacy and safety of baculovirus-based bioinsecticides

Insect pest control is a key mechanism to give humans advantage over insects in competition for food resources. Bioinsecticides are highly virulent in target insects, can control their populations and prevent a sharp increase in their number. The bioinsecticide Virin HSK was created in FBRI SRC VB “Vector”. Helicoverpa zea single nuclear polyhedrosis virus strain HS-18 is the active basis for Virin HSK. Here we studied the effectiveness of Helicovex SK and Virin HSK bioinsecticides as cotton bollworms control agent in comparison with the chemical insecticide Pirinex, CE and determined the safety of these insectisides for the entomophage. The flow rate of the working fluid was 200 l/ha. Helicovex SK and Virin HSK protected soybean during bean ripening and corn in the period from wax ripeness to harvesting. Helicovex SK and Virin HSK had higher efficiency than Pirinex KE.

Effect of temperature on the development of baculoviruses

AbstractDevelopment of infection of 4 strains of nuclear polyhedrosis virus (NPV) in third instar Diatraea saccharalis larvae at 10 different temperatures was compared. Two wild strains, the Anticarsia gemmatalis MNPV (AgMNPV) and the Trichoplusia ni MNPV (TnMNPV), and two selected strains, AgMNPV‐D10 and TnMNPV‐D11 were inoculated in 11‐day‐old D. saccharalis larvae and kept in temperatures of 17, 22, 24, 26, 28, 30, 32, 35, 37 and 39°C. The results showed that larval mortality increased with temperature, and the increase of temperature caused also the reduction of lethal time 50% (LT50) values. The maximal polyhedral production was obtained at 28°C for the 4 viral strains and a drastic reduction in the number of polyhedra was observed even for a difference of 2°C above or below this ideal temperature. The selected strains showed a 10‐fold increase in polyhedra yield when compared to the wild type strains.

Physical Mapping of Bombyx mori Nuclear Polyhedrosis Virus Strain D1 : Identification of Novel Interspersed Homologous Regions

Physical Mapping of Bombyx mori Nuclear Polyhedrosis Virus Strain D1 : Identification of Novel Interspersed Homologous Regions

Field Comparison of Different Strains of Gypsy Moth Nuclear Polyhedrosis Virus Against Gypsy Moth (Lepidoptera: Lymantriidae) in Western Maryland in 1990

Gypchek, as the LD P226 strain of the nuclear polyhedrosis virus of the gypsy moth, Lymantria dispar (L.), was compared in small forest plots with the Abington isolate (Pass 10), each at three dosages. Also evaluated were one dose of virus produced in cell culture, one dose of Gypchek applied without sunscreen, and an untreated control. A dose-response was demonstrated for both the Abington and Gypchek strains. The Abington isolate killed significantly faster than the Gypchek strain, but no statistical difference was seen in virulence, as measured by larval mortality, between the two products. Virus produced in cell culture was found to be active in the bioassay of field-collected larvae. The presence or absence of the sunscreen Orzan did not affect results. Treatment effects as measured by late-season field parameters (larval mortality, defoliation, and egg mass population change) were obscured by forest-wide natural mortality factors.

Sequence and in vitro translational analysis of a 1629-nucleotide ORF in Autographa californica nuclear polyhedrosis virus strain E2

The complete nucleotide (nt) sequence of an open reading frame (ORF) (map unit 5.1 to 3.8) from Autographa californica nuclear polyhedrosis virus strain E2 (AcMNPV-E2) has been determined. This 1629-nt ORF has a coding potential for a 61-kDa Pro-rich protein. However, in vitro translation of the 1629-nt ORF and sodium dodecyl sulfate-polyacrylamidegel electrophoresis (SDS-PAGE) revealed a 78-kDa protein product. The discrepancy between the M r predicted by the nt sequence and that obtained from the in vitro translational analysis is due to the high Pro content of this protein. The high Pro content causes anomalous migration of this protein during SDS-PAGE.

Pathological response of the parasitoid, Glyptapanteles militaris, to nuclear polyhedrosis virus-infected armyworm hosts

The development of the embryonic and larval stages of the internal gregarious parsitoid, Glyptapanteles (= Apanteles) militaris, is adversely affected by the hypertrophy strain of a nuclear polyhedrosis virus in the armyworm, Pseudaletia unipuncta. The initial effects are cessation of parasitoid growth and general tissue disruption, followed by the melanization of parasitoid tissues. Melanization spreads from the parasitoids' caudal vesicle throughout the body, culminating in eventual encapsulation in virus-infected hosts. Parasitoids in armyworm hosts infected with the typical strain of nuclear polyhedrosis virus exhibited no abnormal development.

INTERACTIONS BETWEEN TWO BACULOVIRUSES AND SEVERAL INSECT PARASITES

AbstractSeveral parasites were surveyed for their ability to develop to pupation in virus-infected hosts. The tachinid Compsilura concinnata (Meigen), the ichneumonids Campoletis sonorensis (Cameron) and Hyposoter exiguae (Viereck), and the braconid Cotesia marginiventris (Cresson) developed to pupation in the armyworm, Pseudaletia unipuncta (Haworth), infected with either the Hawaiian strain of granulosis virus (HGV) or the hypertrophy strain of nuclear polyhedrosis virus (HNPV). The braconid Chelonus insularis Cresson died after its HGV- or HNPV-infected host P. unipuncta died. On the other hand, the braconid Glyptapanteles militaris (Walsh) died in HNPV-infected P. unipuncta before the host died. Some of these parasites had tissues that were melanized and some were encapsulated by the host. The ichneumonid H. exiguae and the braconids Chelonus insularis and Cotesia marginiventris developed to pupation in HGV-infected Spodoptera exigua (Hübner). In some cases, developmental time of parasites in virus-infected hosts was longer than in control hosts.

Hemolymph factor in armyworm larvae infected with a nuclear-polyhedrosis virus toxic to Apanteles militaris

The parasitoid, Apanteles militaris, was killed or failed to pupate when its armyworm host was infected with the hypertrophic strain of a nuclear-polyhedrosis virus. Virion-free plasma from diseased larvae killed the parasitoids when injected into uninfected larvae. The toxic factor was partially precipitated from plasma that was 50% saturated with ammonium sulfate and was completely precipitated in 50% ethanol or methanol. Parasitoids in larvae infected with the typical strain of nuclear-polyhedrosis virus seemed unaffected.

A strain of nuclear-polyhedrosis virus causing extensive cellular hypertrophy

A newly discovered strain of a nuclear-polyhedrosis virus causes extensive hypertrophy to the tracheal cells of the armyworm, Pseudaletia unipuncta. This extreme hypertrophy, the absence of infection in the fat cells, and the long period of lethal infection clearly differentiate it from the typical strain of a nuclear-polyhedrosis virus which has been described previously. It also differs from the typical strain in causing the following cytopathological changes: an increase in the number and an alteration in the appearance of the mitochondria in the infected cell, the development of innumerable folds in the cell and nuclear membranes, and the formation of electron-transparent areas in the cytoplasm. At an early stage of infection when the cellular hypertrophy is marked, there is at first no virus rods. The rods appear later, and the polyhedra still later. The polyhedra and virus rods of the new strain resemble those of the typical strain. Its infectivity is also enhanced by a granulosis virus in a synergistic association as in the case of the typical strain. When armyworm larvae are fed equal concentrations of the new and the typical strains, very few of them, if any, develop the signs and symptoms of the new strain. The larval specimens, from which the new strain was obtained, had been collected in a field in Hawaii during 1958 and 1960, and showed the typical signs and symptoms of nuclear polyhedrosis at the time of collection. Accordingly, the larval specimens may have been infected originally by two strains of a nuclear-polyhedrosis virus. Three larvae collected in alfalfa fields at Davis, California, also exhibited signs and symptoms of the new strain.