A new ascovirus from Spodoptera exigua and its relatedness to the isolate from Spodoptera frugiperda

A new ascovirus was isolated from Spodoptera exigua in Indonesia and was tentatively assigned as a new species, Spodoptera exigua ascovirus 5a (SeAV-5a) according to the present ICTV ascovirus naming scheme based on DNA restriction fragment length polymorphism (RFLP), hybridization, formation of occlusion body, tissue tropism and host spectrum. SeAV-5a replicated primarily in the fat body of susceptible hosts. SeAV-5a could be transmitted to S. frugiperda, Pseudoplusia includens and Trichoplusia ni, but not to Heliothis virescens. Infection with SeAV-5a arrested growth of the hosts, but prolonged their survival, which continued up to 33 days. Clusters of virions were seen inside the characteristic vesicles. Occasionally, virions were contained within vacuoles (one to five per vacuole) and some virions were embedded in occlusion bodies. The size of the SeAV-5a virion was 347×134 nm; however, aberrant long secondary viral products were also seen. The presence of occlusion body and Southern hybridization and Western immunoblot analyses suggest that SeAV-5a is more closely related to S. frugiperda ascovirus 1a (SfAV-1a) than to Trichoplusia ni ascovirus 2 (TnAV-2). Certain regions of the 182 kb genome of SeAV-5a showed hybridization to that of SfAV-1a. Two fragments in each of the SfAV-1a EcoRI and HindIII digests hybridized to the SeAV-5a genomic DNA probe. Five to eight HindIII and EcoRI fragments in SeAV-5a DNA hybridized to the SfAV-1a genomic probe.

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Bacmid Expression of Granulovirus Enhancin En3 Accumulates in Cell Soluble Fraction to Potentiate Nucleopolyhedrovirus Infection

Viruses ◽

10.3390/v13071233 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1233

Author(s):

Adriana Ricarte-Bermejo ◽

Oihane Simón ◽

Ana Beatriz Fernández ◽

Trevor Williams ◽

Primitivo Caballero

Keyword(s):

Trichoplusia Ni ◽

Recombinant Virus ◽

Spodoptera Exigua ◽

Insect Cells ◽

Soluble Fraction ◽

Autographa Californica ◽

Insect Midgut ◽

Baculovirus Infection ◽

Occlusion Bodies ◽

Infected Cells

Enhancins are metalloproteinases that facilitate baculovirus infection in the insect midgut. They are more prevalent in granuloviruses (GVs), constituting up to 5% of the proteins of viral occlusion bodies (OBs). In nucleopolyhedroviruses (NPVs), in contrast, they are present in the envelope of the occlusion-derived virions (ODV). In the present study, we constructed a recombinant Autographa californica NPV (AcMNPV) that expressed the Trichoplusia ni GV (TnGV) enhancin 3 (En3), with the aim of increasing the presence of enhancin in the OBs or ODVs. En3 was successfully produced but did not localize to the OBs or the ODVs and accumulated in the soluble fraction of infected cells. As a result, increased OB pathogenicity was observed when OBs were administered in mixtures with the soluble fraction of infected cells. The mixture of OBs and the soluble fraction of Sf9 cells infected with BacPhEn3 recombinant virus was ~3- and ~4.7-fold more pathogenic than BacPh control OBs in the second and fourth instars of Spodoptera exigua, respectively. In contrast, when purified, recombinant BacPhEn3 OBs were as pathogenic as control BacPh OBs. The expression of En3 in the soluble fraction of insect cells may find applications in the development of virus-based insecticides with increased efficacy.

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SYNERGISM OF PYRETHROIDS BY PIPERONYL BUTOXIDE AND MGK-264 AGAINST HELIOTHIS VIRESCENS, SPODOPTERA EXIGUA, AND SPODOPTERA FRUGIPERDA (LEPIDOPTERA: NOCTUIDAE)1

Journal of Entomological Science ◽

10.18474/0749-8004-23.3.229 ◽

1988 ◽

Vol 23 (3) ◽

pp. 229-233

Author(s):

J. A. Joyce ◽

R. J. Ottens ◽

G. A. Herzog ◽

M. H. Bass

Keyword(s):

Spodoptera Frugiperda ◽

Heliothis Virescens ◽

Spodoptera Exigua ◽

Synergistic Effects ◽

Fall Armyworm ◽

Piperonyl Butoxide ◽

Tobacco Budworm ◽

Lepidoptera Noctuidae ◽

Beet Army Worm ◽

Army Worm

Laboratory cultures of field-collected larval tobacco budworm, Heliothis virescens (F.), beet army worm, Spodoptera exigua (Hübner), and fall armyworm, S. frugiperda (J. E. Smith) were bioassayed for response to three pyrethroids in combination with piperonyl butoxide (PBO), or MGK-264. The greatest synergistic effects were seen in S. exigua which also displayed the greatest tolerance to pyrethroids without synergists. The highest SR50 (synergist ratio) value for S. exigua was 22.1 with fenvalerate-PBO mixed in a ratio of 1:5, the highest for S. frugiperda was 4.6 with fenvalerate-MGK-264 1:5, and the highest for H. virescens was 1.3 with permethrin-MGK-264 1:5 or with fenvalerate-PBO 1:5.

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Population Dynamics of Six Major Insect Pests During Multiple Crop Growing Seasons in Northwestern New Mexico

Insects ◽

10.3390/insects10110369 ◽

2019 ◽

Vol 10 (11) ◽

pp. 369 ◽

Cited By ~ 1

Author(s):

Djaman ◽

Higgins ◽

O’Neill ◽

Begay ◽

Koudahe ◽

...

Keyword(s):

Population Dynamics ◽

Spodoptera Frugiperda ◽

Trichoplusia Ni ◽

Helicoverpa Zea ◽

Spodoptera Exigua ◽

Insect Pests ◽

Potato Psyllid ◽

Bactericera Cockerelli ◽

Commercial Farm ◽

Striacosta Albicosta

This study was conducted to monitor the population dynamics of six major insect pests at the NMSU Agricultural Science Center at Farmington (ASC-Farmington) and within an adjacent commercial farm (Navajo Agricultural Products Industry, NAPI) for more effective and efficient pest management during the 2013–2019 period. Specific pheromone traps, sticky and net traps were used to collects moths of beet armyworm (Spodoptera exigua), cabbage looper (Trichoplusia ni), corn earworm (Helicoverpa zea), fall armyworm (Spodoptera frugiperda), potato psyllid (Bactericera cockerelli), and western bean cutworm (Striacosta albicosta). These insects generally appear in early June and their population decreases toward the end of August/early September with different peak times and magnitudes during July and August. Bactericera cockerelli was not substantially present in the commercial farm due to intensive insecticide application. Overall, all six insect species were present at ASC-Farmington, with relative abundance, in percent of the total collected moths by all traps, varying from 6.5 to 19% for Trichoplusia ni, 16 to 29.2% for Spodoptera exigua, 1.5 to 20.6% for Striacosta albicosta, 10 to 25% for Helicoverpa zea, 18.5 to 25.6% for Spodoptera frugiperda and 8.5 to 26.9% for Bactericera cockerelli. In NAPI’s commercial field, while the potato psyllid Bactericera cockerelli was not recorded, Trichoplusia ni and Spodoptera exigua showed decreasing rates that varied from 27.5 to 4.2% and from 49.3 to 7.8%, respectively. Striacosta albicosta, Helicoverpa zea and Spodoptera exigua showed increasing rates varying from 2.9 to 28%, from 7.8 to 25.3% and from 10.9 to 52%, respectively. The results of this study could serve as a guideline for sustainable management strategies for each of the six species for production profitability.

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Lack of involvement of haemocytes in the establishment and spread of infection in Spodoptera frugiperda larvae infected with the baculovirus Autographa californica M nucleopolyhedrovirus by intrahaemocoelic injection

Journal of General Virology ◽

10.1099/0022-1317-83-7-1565 ◽

2002 ◽

Vol 83 (7) ◽

pp. 1565-1572 ◽

Cited By ~ 50

Author(s):

Thomas E. Clarke ◽

Rollie J. Clem

Keyword(s):

Spodoptera Frugiperda ◽

Trichoplusia Ni ◽

Fluorescent Protein ◽

Fat Body ◽

Autographa Californica ◽

Green Fluorescent Protein Gene ◽

Primary Role ◽

Late Instar ◽

Noctuid Species ◽

Green Fluorescent

It is thought that insect haemocytes, or blood cells, play an important role in baculovirus pathogenesis by amplifying and helping to spread the infection within the insect. Here, infection is described of the lepidopteran noctuid species Spodoptera frugiperda with the baculovirus Autographa californica M nucleopolyhedrovirus (AcMNPV). Late instar S. frugiperda larvae were infected by intrahaemocoelic injection using a recombinant of AcMNPV expressing the enhanced green fluorescent protein gene to visualize infected cells. Approximately 1000-fold higher doses of injected virus were required to initiate infection in S. frugiperda larvae than in another permissive noctuid species, Trichoplusia ni. Infected S. frugiperda larvae survived twice as long as T. ni larvae and exhibited a slower build-up of virus in the haemolymph. In S. frugiperda, infection of fat body and epithelium was observed prior to significant infection of haemocytes, even though the virus was delivered by intrahaemocoelic injection. Expression of eGFP was first detected 12–18 h post-injection within the fat body and, by 24 h, infection had spread to the tracheal and body wall epithelium. In contrast, only 5% of haemocytes were infected at 24 h and the proportion of infected haemocytes increased slowly to only around 50% at 5 days post-infection, when most larval death occurred. Thus, in S. frugiperda, haemocytes do not appear to have a primary role in AcMNPV pathogenesis. This relative lack of infection of haemocytes may in part explain why S. frugiperda larvae are more resistant to AcMNPV infection than T. ni larvae.

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Sex Pheromones of Noctuid Moths. V. Circadian Rhythm of Pheromone-Responsiveness in Males of Autographa californica, Heliothis virescens, Spodoptera exigua, and Trichoplusia ni (Lepidoptera: Noctuidae)12

Annals of the Entomological Society of America ◽

10.1093/aesa/58.5.597 ◽

1965 ◽

Vol 58 (5) ◽

pp. 597-600 ◽

Cited By ~ 34

Author(s):

H. H. Shorey ◽

Lyle K. Gaston

Keyword(s):

Circadian Rhythm ◽

Heliothis Virescens ◽

Trichoplusia Ni ◽

Sex Pheromones ◽

Spodoptera Exigua ◽

Autographa Californica ◽

Lepidoptera Noctuidae

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Persistence of an Occlusion-Negative Recombinant Nucleopolyhedrovirus in Trichoplusia ni Indicates High Multiplicity of Cellular Infection

Applied and Environmental Microbiology ◽

10.1128/aem.67.11.5204-5209.2001 ◽

2001 ◽

Vol 67 (11) ◽

pp. 5204-5209 ◽

Cited By ~ 50

Author(s):

James C. Bull ◽

H. C. J. Godfray ◽

David R. O'Reilly

Keyword(s):

Trichoplusia Ni ◽

Serial Passage ◽

Virus Genome ◽

Occlusion Body ◽

Wild Type ◽

Viral Genomes ◽

Occlusion Bodies ◽

Nuclear Polyhedrosis ◽

Mutant Forms ◽

Virus Genomes

ABSTRACT We use data from the serial passage of co-occluded recombinantAutographa californica nuclear polyhedrosis virus (AcMNPV) to estimate the viral multiplicity of infection of cells within infected insects. Co-occlusion, the incorporation of wild-type and mutant virus genomes in the same occlusion body, has been proposed as a strategy to deliver genetically modified viruses as insecticides in a way that contains their spread in the environment. It may also serve as a means whereby naturally occurring mutant forms of NPVs can be maintained in a stable polymorphism. Here, a recombinant strain of AcMNPV was constructed with a deletion of itspolyhedrin gene, rendering it incapable of producing occlusion bodies (i.e., occlusion negative). This was co-occluded with wild-type AcMNPV and used to infect fifth-instarTrichoplusia ni larvae. The fate of both genotypes was monitored over several rounds of insect infection. Levels of the occlusion-negative virus genome declined slowly over successive rounds of infection. We applied these data to a model of NPV population genetics to derive an estimate of 4.3 ± 0.3 viral genomes per occlusion body-producing cell.

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Heliothis virescens ascovirus 3h blocks the cell cycle of Spodoptera exigua fat body cells at G 2 /M phase by downregulating cyclin B 1 and cyclin‐dependent kinase 1

Journal of Cellular Physiology ◽

10.1002/jcp.30665 ◽

2021 ◽

Author(s):

Xiao‐Hui Song ◽

Ni Li ◽

Chang‐Jin Yang ◽

Yanyang Wu ◽

Guo‐Hua Huang

Keyword(s):

Cell Cycle ◽

Heliothis Virescens ◽

Spodoptera Exigua ◽

Fat Body ◽

Cyclin B ◽

Cyclin Dependent Kinase ◽

M Phase ◽

Heliothis Virescens Ascovirus

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Sequence and organization of the Heliothis virescens ascovirus genome

Journal of General Virology ◽

10.1099/vir.0.82651-0 ◽

2007 ◽

Vol 88 (4) ◽

pp. 1120-1132 ◽

Cited By ~ 39

Author(s):

Sassan Asgari ◽

John Davis ◽

David Wood ◽

Peter Wilson ◽

Annette McGrath

Keyword(s):

Nucleotide Sequence ◽

Spodoptera Frugiperda ◽

Heliothis Virescens ◽

Trichoplusia Ni ◽

Open Reading Frames ◽

Homologous Genes ◽

Circular Genome ◽

Genes Encoding ◽

Heliothis Virescens Ascovirus ◽

Reading Frames

The nucleotide sequence of the Heliothis virescens ascovirus (HvAV-3e) DNA genome was determined and characterized in this study. The circular genome consists of 186 262 bp, has a G+C content of 45.8 mol% and encodes 180 potential open reading frames (ORFs). Five unique homologous regions (hrs), 23 ‘baculovirus repeat ORFs' (bro) and genes encoding a caspase homologue and several enzymes involved in nucleotide replication and metabolism were found in the genome. Several ascovirus (AV)-, iridovirus- and baculovirus-homologous genes were identified. The genome is significantly larger than the recently sequenced genomes of Trichoplusia ni AV (TnAV-2c) and Spodoptera frugiperda AV (SfAV-1a). Gene-parity plots and overall similarity of ORFs indicate that HvAV-3e is related more closely to SfAV-1a than to TnAV-2c.

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