Subfamily: Entomopoxvirinae

Genus: Betaentomopoxvirus

Distinguishing features

The genus includes poxviruses that infect insects of the order Lepidoptera. The genus includes 16 species. Mature virions are occluded within spheroids after cell disintegration and are thought to be important for dissemination. Disease signs include; re-organisation of the host cell cytoskeleton, arrested moulting of the larvae, larval paralysis, loss of coordination and lethargy.

Virion

Virions are ovoid and brick-shaped and are approximately 225–275 × 320–375 nm in size, with a cylindrical core and sleeve-shaped lateral bodies. Surface globular units give the virion a mulberry-shaped appearance and are approximately 40 nm in diameter.

Genome organization and replication

There are currently 5 members of the genus Betaentomopoxvirus that have fully sequenced genomes. Their dsDNA genomes range from 228–307 kbp, encoding 247–334 putative genes; the G + C content is approximately 18–21%. The inverted terminal repeats vary from approximately 5.5–24 kbp. For the betaentomopoxviruses sequenced to date there are approximately 148 genes that are conserved between viruses and that are also relatively co-linear. There are 104 genes shared with members of other entomopoxvirus genera (Bawden et al., 2000, Thézé et al., 2013). Phylogenetic analyses using the 49 genes common to the family Poxviridae supports classification into two subfamilies, as well as the separation of the lepidopteran entompoxviruses from the orthopteran entomopoxvirus (Melanoplus sanguinipes entomopoxvirus,genus Deltaentomopoxvirus) which were previously grouped together in the same genus based on virion morphology.

For replication, please see discussion under family description.

Species demarcation criteria

Species demarcation is based on host range. As more complete genome sequences become available gene content and synteny are likely to be used.