Non-occluded virus

Pronunciation
/non uh-KLOO-ded VY-rus/
Category
Disease Ecology
Singular
non-occluded virus
Plural
non-occluded viruses

Definition

An insect virus that lacks an occlusion body—a crystalline protein matrix that normally embeds and protects in the environment. Non-occluded viruses (NOVs) are transmitted horizontally or vertically without the durable, soil-persistent packaging that characterizes occluded viruses such as (NPVs) and (GVs). Their naked virions are generally more susceptible to environmental inactivation, requiring direct -to-host transmission or preservation within host tissues.

Etymology

From Latin 'occludere' (to shut up, enclose), with the negative prefix 'non-'; refers to the absence of the proteinaceous occlusion body that encloses in related virus groups.

Example

The non-occluded virus HzNV-1 ( nudivirus 1) infects ; unlike the occluded Helicoverpa armigera used as a , HzNV-1 spreads through venereal transmission and vertical inheritance without forming protective polyhedra, making it poorly suited for environmental persistence but effective as a covert, vertically maintained .

Synonyms

  • NOV
  • non-occluded baculovirus (historical, deprecated)
  • nudivirus (when referring to specific taxonomic group)

Related Terms

Usage Notes

The term is morphological, not strictly taxonomic: historically, some NOVs were classified as 'non-occluded ,' but molecular placed many in separate (Nudiviridae, ). now reserve 'non-occluded virus' for descriptive contexts emphasizing the absence of occlusion bodies, while using formal taxonomic names (e.g., nudivirus, ) for classification. Contrast with 'occluded virus' is essential in biocontrol: occlusion bodies enable as stable, sprayable , whereas NOVs typically require living or culture for propagation and delivery.