Genomic analysis of hyperparasitic viruses associated with entomopoxviruses.

Polinton-like viruses (PLVs) are a diverse group of small integrative dsDNA viruses that infect diverse eukaryotic hosts. Many PLVs are hypothesized to parasitize viruses in the phylum for their own propagation and spread. Here, we analyze the genomes of novel PLVs associated with the occlusion bodies of entomopoxvirus (EPV) infections of two separate lepidopteran hosts.

Conserved infections and reproductive phenotypes of Wolbachia symbionts in Asian tortrix moths.

Wolbachia is a ubiquitous endosymbiotic bacterium that manipulates insect reproduction. A notable feature of Wolbachia is male killing (MK), whereby sons of infected females are killed during development; however, the evolutionary processes by which Wolbachia acquired the MK ability remain unclear. The tea tortrix moth Homona magnanima (Tortricidae) harbours three non-MK Wolbachia strains (wHm-a, wHm-b and wHm-c) and an MK strain wHm-t.

Diverse Molecular Mechanisms Underlying Microbe-Inducing Male Killing in the Moth Homona magnanima.

Male killing (MK) is a type of reproductive manipulation induced by microbes, where sons of infected mothers are killed during development. MK is a strategy that enhances the fitness of the microbes, and the underlying mechanisms and the process of their evolution have attracted substantial attention. Homona magnanima, a moth, harbors two embryonic MK bacteria, namely, () and (), and a larval MK virus, Osugoroshi virus (OGV; Partitiviridae).

Distinct effects of three Wolbachia strains on fitness and immune traits in Homona magnanima.

The endosymbiotic bacterium Wolbachia occasionally increases host fitness or manipulates host reproductions to enhance vertical transmission. Multiple Wolbachia strains can coinfect the same host individual, which alters the density as well as phenotypes of the bacteria. However, the effects of Wolbachia coinfection on host fitness remain largely unknown.

Insight into the regulation of the Nrf2 pathway in response to ascovirus infection in Spodoptera exigua.

Background: Ascoviruses are a type of entomopathogenic microorganism with high biological pest control potential and are expected to contribute to the natural control of lepidopteran pests. However, knowledge of the molecular mechanism underlying the biocidal activity of ascovirus on its host insects remains limited.

Results: In this study, the relative enzyme activity of superoxide dismutase and peroxidase, as well as the expression level of Spodoptera exigua peroxidase (SePOD), were found to be significantly increased at 6 h post infection with Heliothis virescens ascovirus 3h (HvAV-3h).

Chelonus inanitus bracovirus encodes lineage-specific proteins and truncated immune IκB-like factors.

Bracoviruses and ichnoviruses are endogenous viruses of parasitic wasps that produce particles containing virulence genes expressed in host tissues and necessary for parasitism success. In the case of bracoviruses the particles are produced by conserved genes of nudiviral origin integrated permanently in the wasp genome, whereas the virulence genes can strikingly differ depending on the wasp lineage. To date most data obtained on bracoviruses concerned species from the braconid subfamily of Microgastrinae.

Mass-Rearing and Molecular Studies in Tortricidae Pest Insects.

Tortricidae (Lepidoptera), commonly known as tortrix or leafroller moths, comprises many agricultural and forestry pests, which cause serious agricultural losses. To understand the biology of such pest moths, fundamental techniques have been in high demand. Here, methods for mass-rearing, observations, and molecular studies are developed using two tea tortrix, Homona magnanima and Adoxophyes honmai (Lepidoptera: Tortricidae).

Cross-Resistance of the Codling Moth against Different Isolates of Cydia pomonella Granulovirus Is Caused by Two Different but Genetically Linked Resistance Mechanisms.

Cydia pomonella granulovirus (CpGV) is a widely used biological control agent of the codling moth. Recently, however, the codling moth has developed different types of field resistance against CpGV isolates. Whereas type I resistance is Z chromosomal inherited and targeted at the viral gene of isolate CpGV-M, type II resistance is autosomal inherited and targeted against isolates CpGV-M and CpGV-S.

Confirmation of Oryctes rhinoceros nudivirus infections in G-haplotype coconut rhinoceros beetles (Oryctes rhinoceros) from Palauan PCR-positive populations.

Coconut rhinoceros beetle (CRB), Oryctes rhinoceros, is a pest of palm trees in the Pacific. Recently, a remarkable degree of palm damage reported in Guam, Hawaii, Papua New Guinea and Solomon Islands has been associated with a particular haplotype (clade I), known as "CRB-G". In the Palau Archipelago, both CRB-G and another haplotype (clade IV) belonging to the CRB-S cluster coexist in the field.

Horizontally transmitted parasitoid killing factor shapes insect defense to parasitoids.

Interkingdom competition occurs between hymenopteran parasitoids and insect viruses sharing the same insect hosts. It has been assumed that parasitoid larvae die with the death of the infected host or as result of competition for host resources. Here we describe a gene family, (), that encodes proteins toxic to parasitoids of the Microgastrinae group and determines parasitism success.

3H-31, A Non-structural Protein of Heliothis virescens ascovirus 3h, Inhibits the Host Larval Cathepsin and Chitinase Activities.

3h-31 of Heliothis virescens ascovirus 3h (HvAV-3h) is a highly conserved gene of ascoviruses. As an early gene of HvAV-3h, 3h-31 codes for a non-structural protein (3H-31) of HvAV-3h. In the study, 3h-31 was initially transcribed and expressed at 3 h post-infection (hpi) in the infected Spodoptera exigua fat body cells (SeFB).

Coexistence of Two Male-Killers and Their Impact on the Development of Oriental Tea Tortrix Homona magnanima.

Male-killing, the death of male offspring induced by maternally transmitted microbes, is classified as early, or late, male-killing. The primary advantage afforded by early male-killing, which typically occurs during embryogenesis, is the reallocation of resources to females, that would have otherwise been consumed by males. Meanwhile, the key advantage of late male-killing, which typically occurs during late larval development, is the maximized potential for horizontal transmission.

Direct and sensitive detection of a microsporidian parasite of bumblebees using loop-mediated isothermal amplification (LAMP).

The reduction of bumblebee populations has been reported in the last decades, and the microsporidian parasite Nosema bombi is considered as one of the factors contributing to such reduction. Although the decline of bee populations affects both wild plants and human food supply, the effects of Nosema spp. infections are not known because it is difficult to obtain infective spores from wild bees due to their low prevalence.

Closely Related Male-Killing and Nonmale-Killing Wolbachia Strains in the Oriental Tea Tortrix Homona magnanima.

Wolbachia are inherited intracellular bacteria that cause male-specific death in some arthropods, called male-killing. To date, three Wolbachia strains have been identified in the oriental tea tortrix Homona magnanima (Tortricidae, Lepidoptera); however, none of these caused male-killing in the Japanese population. Here, we describe a male-killing Wolbachia strain in Taiwanese H.

In Vitro Infectious Risk Assessment of Heliothis virescens ascovirus 3j (HvAV-3j) toward Non-target Vertebrate Cells.

As specific pathogens of noctuid pests, including Spodoptera exigua, S. litura, Helicoverpa armigera, and Mythimna separata, ascoviruses are suitable for the development of bioinsecticides. In this study, the infectivity of Heliothis virescens ascovirus 3j (HvAV-3j) on insect and mammalian cells was evaluated.

Multiple Infection and Reproductive Manipulations of Wolbachia in Homona magnanima (Lepidoptera: Tortricidae).

Endosymbiotic bacterium Wolbachia interacts with host in either a mutualistic or parasitic manner. Wolbachia is frequently identified in various arthropod species, and to date, Wolbachia infections have been detected in different insects. Here, we found a triple Wolbachia infection in Homona magnanima, a serious tea pest, and investigated the effects of three infecting Wolbachia strains (wHm-a, -b, and -c) on the host.

The virome of , an invasive pest of soft fruit.

(Matsumura) is one of the most damaging and costly pests to invade temperate horticultural regions in recent history. Conventional control of this pest is challenging, and an environmentally benign microbial biopesticide is highly desirable. A thorough exploration of the pathogens infecting this pest is not only the first step on the road to the development of an effective biopesticide, but also provides a valuable comparative dataset for the study of viruses in the model family .

Morphological properties of the occlusion body of Adoxophyes orana granulovirus.

A granulovirus (GV) that produces occlusion bodies (OBs) having an unusual morphology was found in an Adoxophyes sp. (Lepidoptera: Tortricidae) larva in a tea field in Miyazaki Prefecture, Japan. This isolate is considered to be a mutant of Adoxophyes orana granulovirus, designated AdorGV-M, because the nucleotide sequence of its genome is 99.

An ascovirus isolated from Spodoptera litura (Noctuidae: Lepidoptera) transmitted by the generalist endoparasitoid Meteorus pulchricornis (Braconidae: Hymenoptera).

The family Ascoviridae is a recently described virus family whose members are transmitted by parasitoids and cause chronic and lethal infections in lepidopteran insects. Little is known about the biology and ecology of ascoviruses, and few isolates have been found outside the United States. We report here the isolation of a new ascovirus variant from Spodoptera litura in Japan.

Comparison of tolerance to sunlight between spatially distant and genetically different strains of Lymantria dispar nucleopolyhedrovirus.

Baculoviruses are a family of insect-specific pathogenic viruses can persist outside for long periods through the formation of occlusion bodies. In spite of this ability, the UV of sunlight is an essential factor that limits the survival of baculoviruses outside the host. In the current study, we compared the UV tolerance of two strains of Lymantria dispar multiple nucleopolyhedrovirus (LdMNPV), which were isolated in spatially different regions (LdMNPV-27/0 in Western Siberia (Russia) and LdMNPV-45/0 in North America (USA)) and dramatically differ in their potency.

A virus carries a gene encoding juvenile hormone acid methyltransferase, a key regulatory enzyme in insect metamorphosis.

Microbial parasitism, infection, and symbiosis in animals often modulate host endocrine systems, resulting in alterations of phenotypic traits of the host that can have profound effects on the ecology and evolution of both the microorganisms and their hosts. Information about the mechanisms and genetic bases of such modulations by animal parasites is available from studies of steroid hormones. However, reports involving other hormones are scarce.

Identification of an Early Male-Killing Agent in the Oriental Tea Tortrix, Homona magnanima.

Arthropods are frequently infected with inherited symbionts, which sometimes confer fitness benefits on female hosts or manipulate host reproduction. Early male killing, in which infected males die during embryogenesis, is induced by some bacteria, such as Wolbachia and Spiroplasma. A female-biased sex ratio has been found in Homona magnanima, collected from a tea plantation in Japan.