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.

Whole-genome sequence of , isolate recovered from the gut of feeding on cabbage.

We present the whole-genome sequence of (previously ) obtained from long and short reads. It is a dominant gut symbiont of the notorious crop pest , highly prevalent in lepidopteran midguts and a useful model for the evolution of resistance to antimicrobials.

Nudiviruses in free-living and parasitic arthropods: evolutionary taxonomy.

The nudiviruses (family: Nudiviridae) are large double-stranded DNA (dsDNA) viruses that infect insects and crustaceans, and have most recently been identified from ectoparasitic members (fleas and lice). This virus family was created in 2014 and has since been expanded via the discovery of multiple novel viral candidates or accepted members, sparking the need for a new taxonomic and evolutionary overview. Using current information (including data from public databases), we construct a new comprehensive phylogeny, encompassing 49 different nudiviruses.

A novel and diverse family of filamentous DNA viruses associated with parasitic wasps.

Large dsDNA viruses from the class are currently composed of four viral families infecting insects and/or crustaceans. Since the 1970s, particles described as filamentous viruses (FVs) have been observed by electronic microscopy in several species of Hymenoptera parasitoids but until recently, no genomic data was available. This study provides the first comparative morphological and genomic analysis of these FVs.

The effect of diet composition on the diversity of active gut bacteria and on the growth of Spodoptera exigua (Lepidoptera: Noctuidae).

Gut microbiota plays a functional role in nutrition among several insects. However, the situation is unclear in Lepidoptera. Field studies suggest the microbiome may not be stable and is determined by diet, while in the laboratory, Lepidoptera are routinely reared on diet containing antibiotics with unknown effects on microbial communities.

Persisting roadblocks in arthropod monitoring using non-destructive metabarcoding from collection media of passive traps.

Background: Broad-scale monitoring of arthropods is often carried out with passive traps ( Malaise traps) that can collect thousands of specimens per sample. The identification of individual specimens requires time and taxonomic expertise, limiting the geographical and temporal scale of research and monitoring studies. DNA metabarcoding of bulk-sample homogenates has been found to be faster, efficient and reliable, but the destruction of samples prevents validation of species occurrences and relative abundances.

Developments in the classification and nomenclature of arthropod-infecting large DNA viruses that contain pif genes.

Viruses of four families of arthropod-specific, large dsDNA viruses (the nuclear arthropod large DNA viruses, or NALDVs) possess homologs of genes encoding conserved components involved in the baculovirus primary infection mechanism. The presence of such homologs encoding per os infectivity factors (pif genes), along with their absence from other viruses and the occurrence of other shared characteristics, suggests a common origin for the viruses of these families. Therefore, the class Naldaviricetes was recently established, accommodating these four families.

Changes in Bacterial Community Structure Across the Different Life Stages of Black Soldier Fly (Hermetia illucens).

The digestive capacity of organic compounds by the black soldier fly (BSF, Hermetia illucens, Diptera: Stratiomyidae, Linnaeus, 1758) is known to rely on complex larva-microbiota interactions. Although insect development is known to be a driver of changes of bacterial communities, the fluctuations along BSF life cycle in terms of composition and diversity of bacterial communities are still unknown. In this work, we used a metabarcoding approach to explore the differences in bacterial diversity along all four BSF developmental stages: eggs, larvae, pupae, and adult.

First Evidence of Past and Present Interactions between Viruses and the Black Soldier Fly, .

Black soldier flies (BSFs, ) are becoming a prominent research model encouraged by the insect as food and feed and waste bioconversion industries. Insect mass-rearing facilities are at risk from the spread of viruses, but so far, none have been described in BSFs. To fill this knowledge gap, a bioinformatic approach was undertaken to discover viruses specifically associated with BSFs.

Climate-induced forest dieback drives compositional changes in insect communities that are more pronounced for rare species.

Species richness, abundance and biomass of insects have recently undergone marked declines in Europe. We metabarcoded 211 Malaise-trap samples to investigate whether drought-induced forest dieback and subsequent salvage logging had an impact on ca. 3000 species of flying insects in silver fir Pyrenean forests.

Virulence and genetic characterization of six baculovirus strains isolated from different populations of Spodoptera frugiperda (Lepidoptera: Noctuidae).

Fall armyworm (FAW), Spodoptera frugiperda (Smith, 1797), is a polyphagous, voracious, and economically important agricultural pest. Biological control of FAW is a strategy that must be further explored. This study evaluated six baculovirus strains isolated from infected FAW larvae from Mexico, Argentina, Honduras, and the United States.

Monitoring Insect Transposable Elements in Large Double-Stranded DNA Viruses Reveals Host-to-Virus and Virus-to-Virus Transposition.

The mechanisms by which transposable elements (TEs) can be horizontally transferred between animals are unknown, but viruses are possible candidate vectors. Here, we surveyed the presence of host-derived TEs in viral genomes in 35 deep sequencing data sets produced from 11 host-virus systems, encompassing nine arthropod host species (five lepidopterans, two dipterans, and two crustaceans) and six different double-stranded (ds) DNA viruses (four baculoviruses and two iridoviruses). We found evidence of viral-borne TEs in 14 data sets, with frequencies of viral genomes carrying a TE ranging from 0.

Chromosomal scale assembly of parasitic wasp genome reveals symbiotic virus colonization.

Endogenous viruses form an important proportion of eukaryote genomes and a source of novel functions. How large DNA viruses integrated into a genome evolve when they confer a benefit to their host, however, remains unknown. Bracoviruses are essential for the parasitism success of parasitoid wasps, into whose genomes they integrated ~103 million years ago.

Wide spectrum and high frequency of genomic structural variation, including transposable elements, in large double-stranded DNA viruses.

Our knowledge of the diversity and frequency of genomic structural variation segregating in populations of large double-stranded (ds) DNA viruses is limited. Here, we sequenced the genome of a baculovirus ( multiple nucleopolyhedrovirus [AcMNPV]) purified from beet armyworm () larvae at depths >195,000× using both short- (Illumina) and long-read (PacBio) technologies. Using a pipeline relying on hierarchical clustering of structural variants (SVs) detected in individual short- and long-reads by six variant callers, we identified a total of 1,141 SVs in AcMNPV, including 464 deletions, 443 inversions, 160 duplications, and 74 insertions.

Occurrence and Molecular Phylogeny of Honey Bee Viruses in Vespids.

Since the discovery that honey bee viruses play a role in colony decline, researchers have made major breakthroughs in understanding viral pathology and infection processes in honey bees. Work on virus transmission patterns and virus vectors, such as the mite , has prompted intense efforts to manage honey bee health. However, little is known about the occurrence of honey bee viruses in bee predators, such as vespids.

Viruses in the Invasive Hornet .

The Asian yellow-legged hornet , a major predator of honeybees, is spreading in Europe in part due to a lack of efficient control methods. In this study, as a first step to identify biological control agents, we characterized viral RNA sequences present in asymptomatic or symptomatic hornets. Among 19 detected viruses, the honey bee virus was predominant in all the samples, particularly in muscles from the symptomatic hornet, suggesting a putative cause of the deformed wing symptom.

Biodiversity, Evolution and Ecological Specialization of Baculoviruses: A Treasure Trove for Future Applied Research.

The , a family of insect-specific large DNA viruses, is widely used in both biotechnology and biological control. Its applied value stems from millions of years of evolution influenced by interactions with their hosts and the environment. To understand how ecological interactions have shaped baculovirus diversification, we reconstructed a robust molecular phylogeny using 217 complete genomes and ~580 isolates for which at least one of four lepidopteran core genes was available.

ICTV Virus Taxonomy Profile: Baculoviridae.

The family Baculoviridae comprises large viruses with circular dsDNA genomes ranging from 80 to 180 kbp. The virions consist of enveloped, rod-shaped nucleocapsids and are embedded in distinctive occlusion bodies measuring 0.15-5 µm.

The Domestication of a Large DNA Virus by the Wasp Venturia canescens Involves Targeted Genome Reduction through Pseudogenization.

Polydnaviruses (PDVs) are compelling examples of viral domestication, in which wasps express a large set of genes originating from a chromosomally integrated virus to produce particles necessary for their reproductive success. Parasitoid wasps generally use PDVs as a virulence gene delivery system allowing the protection of their progeny in the body of parasitized host. However, in the wasp Venturia canescens an independent viral domestication process led to an alternative strategy as the wasp incorporates virulence proteins in viral liposomes named virus-like particles (VLPs), instead of DNA molecules.

Genetic footprints of adaptive divergence in the bracovirus of Cotesia sesamiae identified by targeted resequencing.

The African parasitoid wasp Cotesia sesamiae is a generalist species structured in locally adapted populations showing differences in host range. The recent discovery of Cotesia typhae, a specialist, sister species to C. sesamiae, provides a good framework to study the genetic determinants of parasitoid host range.

Discovery of associated tunisia virus: a new ssRNA(+) virus representing a new insect associated virus family.

In the global context of arboviral emergence, deep sequencing unlocks the discovery of new mosquito-borne viruses. Mosquitoes of the species , , and were sampled from 22 locations worldwide for transcriptomic analyses. A virus discovery pipeline was used to analyze the dataset of 0.