Family: Nyamiviridae

Genus: Formivirus

Distinguishing features

The genus Formivirus includes six species. The viruses Formica fusca virus 1 (FfusV-1) and Formica exsecta virus 4 (FeV-4) were discovered in ants belonging to two species (Dhaygude et al., 2019, Kleanthous et al., 2019). Hymenopteran orino-related virus OKIAV85 (HORV-85) and hymenopteran orino-related virus OKIAV87 (HORV 87) were identified in hymenopteran insects by high throughput sequencing (Käfer et al., 2019). Solenopsis invicta virus 15 (SoINV-15) was identified in red fire ants (Xavier et al., 2021). Xiangshan nyami-like virus (XNyV) was identified in the metagenome of wild insect pollinators. Formiviruses are phylogenetically related to viruses in the genus Orinovirus, but form a well-supported distinct lineage (Figure 3.Nyamiviridae).

Virion

Morphology

Not reported.

Nucleic acid

Non-segmented, negative-sense RNA.

Proteins

Formivirus genomes encode five proteins including a putative nucleocapsid protein, phosphoprotein, matrix protein, glycoprotein and large protein identified on the basis of sequence similarity and structural properties shared with mononegavirus homologues.

Genome organization and replication

Formiviruses have a non-segmented negative-sense RNA genome of about 10 kb. The genome encodes five ORFs in the conserved order 3′-N-P-M-G-L-5′. There are no data on virus replication.

Biology

There are no data on virus biology beyond the host. FfusV-1 and FeV-4 were discovered in transcriptome datasets of common black ant (Formica fusca Linnaeus, 1758) and excised wood ant (Formica exsecta Nylander, 1846), respectively. HORV-85 and HORV-87 were discovered in transcriptome shotgun assemblies of a sand wasp (Gorytes laticinctus Lepeletier, 1832) and a blue mud dauber wasp (Chalybion californicum Saussure, 1867), respectively. SoINV-15 was discovered in the transcriptome of red fire ants (Solenopsis invicta Buren, 1972).

Species demarcation criteria

Species are demarcated based upon their members’ phylogeny and hosts.