Growth Characteristics and Competitive Abilities of a Nucleopolyhedrovirus and an Entomopoxvirus in Larvae of the Smaller Tea Tortrix, Adoxophyes honmai (Lepidoptera: Tortricidae)

Ishii, Takayoshi; Takatsuka, Jun; Nakai, M.; Kunimi, Yasuhisa

doi:10.1006/bcon.2001.0988

Cited by 45 publications

(39 citation statements)

References 33 publications

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“…Few studies have addressed interactions between multiple insect pathogens within one host, but evidence to date indicates that pathogens may act either in synergy or interference when they infect the same host individual (Malakar et al 1999b, Ishii et al 2002, Thomas et al 2003, Hughes and Boomsma 2004. Virtually all studies of co-infection of insect hosts have been conducted in laboratory settings and have provided some evidence that infection by one pathogen may alter the host's physiology and make it more or less suitable for a second pathogen.…”

Section: Introductionmentioning

confidence: 99%

Emergent fungal entomopathogen does not alter density dependence in a viral competitor

Liebhold

Plymale

Elkinton

et al. 2013

Ecology

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Abstract. Population cycles in forest Lepidoptera often result from recurring densitydependent epizootics of entomopathogens. While these systems are typically dominated by a single pathogen species, insects are often infected by multiple pathogens, yet little is known how pathogens interact to affect host dynamics. The apparent invasion of northeastern North America by the fungal entomopathogen Entomophaga maimaiga some time prior to 1989 provides a unique opportunity to evaluate such interactions. Prior to the arrival of E. maimaga, the oscillatory dynamics of host gypsy moth, Lymantria dispar, populations were apparently driven by epizootics of a nucleopolyhedrovirus. Subsequent to its emergence, E. maimaiga has caused extensive mortality in host populations, but little is known about how it has altered multigenerational dynamics of the gypsy moth and its virus. Here we compared demographic data collected in gypsy moth populations prior to vs. after E. maimaiga's invasion. We found that the recently invading fungal pathogen virtually always causes greater levels of mortality in hosts than does the virus, but fungal mortality is largely density independent. Moreover, the presence of the fungus has apparently not altered the gypsy mothvirus density-dependent interactions that were shown to drive periodic oscillations in hosts before the arrival of the fungus.

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Section: Introductionmentioning

confidence: 99%

Emergent fungal entomopathogen does not alter density dependence in a viral competitor

Liebhold

Plymale

Elkinton

et al. 2013

Ecology

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“…Apparently, EPVs use hemocytes to spread within susceptible tissues (11). The course of EPV infection is generally slow (13); insects can survive as long as several weeks after the initial infection and can even remain in the larval stage longer than an uninfected host (17). OBs are disseminated in the environment through regurgitation, defecation, and, ultimately, the disintegra-tion of dead hosts (11,18).…”

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confidence: 99%

New Insights into the Evolution of Entomopoxvirinae from the Complete Genome Sequences of Four Entomopoxviruses Infecting Adoxophyes honmai, Choristoneura biennis, Choristoneura rosaceana, and Mythimna separata

Thézé

Takatsuka

Li³

et al. 2013

J Virol

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dPoxviruses are nucleocytoplasmic large DNA viruses encompassing two subfamilies, the Chordopoxvirinae and the Entomopoxvirinae, infecting vertebrates and insects, respectively. While chordopoxvirus genomics have been widely studied, only two entomopoxvirus (EPV) genomes have been entirely sequenced. We report the genome sequences of four EPVs of the Betaentomopoxvirus genus infecting the Lepidoptera: Adoxophyes honmai EPV (AHEV), Choristoneura biennis EPV (CBEV), Choristoneura rosaceana EPV (CREV), and Mythimna separata EPV (MySEV). The genomes are 80% AT rich, are 228 to 307 kbp long, and contain 247 to 334 open reading frames (ORFs). Most genes are homologous to those of Amsacta moorei entomopoxvirus and encode several protein families repeated in tandem in terminal regions. Some genomes also encode proteins of unknown functions with similarity to those of other insect viruses. Comparative genomic analyses highlight a high colinearity among the lepidopteran EPV genomes and little gene order conservation with other poxvirus genomes. As with previously sequenced EPVs, the genomes include a relatively conserved central region flanked by inverted terminal repeats. Protein clustering identified 104 core EPV genes. Among betaentomopoxviruses, 148 core genes were found in relatively high synteny, pointing to low genomic diversity. Whole-genome and spheroidin gene phylogenetic analyses showed that the lepidopteran EPVs group closely in a monophyletic lineage, corroborating their affiliation with the Betaentomopoxvirus genus as well as a clear division of the EPVs according to the orders of insect hosts (Lepidoptera, Coleoptera, and Orthoptera). This suggests an ancient coevolution of EPVs with their insect hosts and the need to revise the current EPV taxonomy to separate orthopteran EPVs from the lepidopteran-specific betaentomopoxviruses so as to form a new genus. Poxviruses are large double-stranded DNA (dsDNA) viruses infecting a wide range of animals. They belong to the phylogenetically related group of viruses termed nucleocytoplasmic large DNA viruses (NCLDV) (1). They harbor linear dsDNA genomes with inverted terminal repeats (ITRs) (2). Poxvirus genomes are 130 to 375 kbp long and replicate in the cytoplasm (3). The family Poxviridae includes two subfamilies: the Chordopoxvirinae, infecting vertebrates, and the Entomopoxvirinae, infecting insects. The chordopoxviruses are classified into nine genera, including Orthopoxvirus and Avipoxvirus (4), and have been the subjects of the main body of research on poxviruses (5, 6). The entomopoxviruses (EPVs) are currently divided into three genera based on host range and virion morphology: Alphaentomopoxvirus, infecting coleopterans; Betaentomopoxvirus, infecting lepidopterans and orthopterans; and Gammaentomopoxvirus, infecting dipterans (4). However, the lack of genomic data has precluded the integration of unifying genetic criteria into this classification. That is why the orthopteran EPV Melanoplus sanguinipes entomopoxvirus was removed from the Betaentomopoxvirus ...

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“…However, very few studies have focused on determining the effect of mixed infections on indicators of viral fitness. For example, mixed infection of the lepidopteran Adoxophyes honmai with a nucleopolyhedrovirus (AdhoNPV) and an entomopoxvirus (dsDNA virus) resulted in a reduction in the fitness of both viruses (Ishii et al, 2002). In contrast, early studies on the interaction of an alphabaculovirus (AcMNPV) with an unclassified RNA virus of Trichoplusia ni revealed that RNA virus-infected larvae had reduced growth compared to healthy insects, but with little or no significant effects on the pathogenicity or speed of kill of alphabaculovirus OBs against host larvae (Vail, Morris & Collier, 1983).…”

Section: Discussionmentioning

confidence: 99%

Iflavirus increases its infectivity and physical stability in association with baculovirus

2016

Draw Science

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Virus transmission and the prevalence of infection depend on multiple factors, including the interaction with other viral pathogens infecting the same host. In this study, active replication of an iflavirus, Spodoptera exigua iflavirus 1 (order Picornavirales) was observed in the offspring of insects that survived following inoculation with a pathogenic baculovirus, Spodoptera exigua multiple nucleopolyhedrovirus. Tracking the origin of the iflavirus suggested the association of this virus with the occlusion bodies of the baculovirus. Here we investigated the effect of this association on the stability and infectivity of both viruses. A reduction in baculovirus pathogenicity, without affecting its infectivity and productivity, was observed when associated with the iflavirus. In contrast, viral association increased the infectivity of the iflavirus and its resistance to ultraviolet radiation and high temperature, two of the main factors affecting virus stability in the field. In addition, electron microscopy analysis revealed the presence of particles resembling iflavirus virions inside the occlusion bodies of the baculovirus, suggesting the possible co-occlusion of both viruses. Results reported here are indicative of facultative phoresis of a virus and suggest that virus-virus interactions may be more common than currently recognized, and may be influential in the ecology of baculovirus and host populations and in consequence in the use of baculoviruses as biological insecticides.

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Growth Characteristics and Competitive Abilities of a Nucleopolyhedrovirus and an Entomopoxvirus in Larvae of the Smaller Tea Tortrix, Adoxophyes honmai (Lepidoptera: Tortricidae)

Cited by 45 publications

References 33 publications

Emergent fungal entomopathogen does not alter density dependence in a viral competitor

Emergent fungal entomopathogen does not alter density dependence in a viral competitor

New Insights into the Evolution of Entomopoxvirinae from the Complete Genome Sequences of Four Entomopoxviruses Infecting Adoxophyes honmai, Choristoneura biennis, Choristoneura rosaceana, and Mythimna separata

Iflavirus increases its infectivity and physical stability in association with baculovirus

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