Subfamily: Entomopoxvirinae

Genus: Deltaentomopoxvirus

Distinguishing features

The genus Deltaentomopxvirus includes a single species, Melanoplus sanguinipes entomopoxvirus, that includes Melanoplus sanguinipes entomopoxvirus 'O' (MSEV), which infects the North American migratory grasshopper and other related orthopteran hosts. Infection is through the midgut, with the fat body being the major target organ for virus replication. Disease develops slowly, is highly debilitating and results in high mortality.

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

The dsDNA genome of MSEV is approximately 236 kbp, encoding an estimated 263 open reading frames (ORFs); the G + C content is approximately 18%. Of the 263 ORFs, 44 partially overlap other ORFs, whilst 28 are wholly contained within longer ORFs. The inverted terminal repeats are approximately 7 kbp (Afonso et al., 1999).

For replication, please see discussion under family description.

Species demarcation criteria

There is only one species in the genus. Species demarcation for other genera in the subfamily are based on host range. As more complete genome sequences become available gene content and synteny are likely to be used.