''Ichnovirus'' is a genus of

viruses A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almo ...

, in the family ''

Polydnaviridae ''Polydnaviriformidae'' ( PDV) is a family of insect viriforms; members are known as polydnaviruses. There are two genera in the family: '' Bracoform'' and '' Ichnoviriform''. Polydnaviruses form a symbiotic relationship with parasitoid wasps. ...

''.

Parasitoid In evolutionary ecology, a parasitoid is an organism that lives in close association with its host (biology), host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionarily stable str ...

wasps serve as hosts, and these wasps are themselves parasitoids of

Lepidoptera Lepidoptera ( ) or lepidopterans is an order (biology), order of winged insects which includes butterflies and moths. About 180,000 species of the Lepidoptera have been described, representing 10% of the total described species of living organ ...

. There are 21 species in this genus.

Taxonomy

The genus ''Ichnovirus'' contained 21 species in ICTV version 1999a-2020: The genus ''Ichnoviriform'' contains 22 species starting ICTV version 2021 The species ''Ichnoviriform rostralis'', previously known as ''Tranosema rostrale bracovirus'' was moved to ichnoviriform from bracoviriform (bracovirus) in 2021.

Structure

Viruses in ''Ichnovirus'' are enveloped, with prolate ellipsoid and cylindrical geometries. Genomes are circular and segmented, around 6.0-20kb in length.

Life cycle

Viral replication is nuclear. DNA-templated transcription is the method of transcription. The virus exits the host cell by nuclear pore export. Parasitoid wasps in the subfamilies Banchinae and Campopleginae serve as hosts, but these wasps are themselves parasites of

lepidoptera Lepidoptera ( ) or lepidopterans is an order (biology), order of winged insects which includes butterflies and moths. About 180,000 species of the Lepidoptera have been described, representing 10% of the total described species of living organ ...

. The wasp injects one or more eggs into its host along with a quantity of virus. The virus and wasp are in a

symbiotic Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biolo ...

relationship: expression of viral genes prevents the wasp's host's immune system from killing the wasp's injected egg and causes other physiological alterations that ultimately cause the parasitized host to die. Transmission routes are parental.

References

External links

Viralzone: Ichnovirus

ICTV
{{Taxonbar, from=Q18822162 Polydnaviridae Virus genera Insect viral diseases