Ascoviridae

Definition

A family of large, enveloped double-stranded DNA viruses in the order Pimascovirales that infect primarily invertebrates, especially noctuid moth larvae (Lepidoptera: Noctuidae) and species of Spodoptera. Ascoviruses are distinguished by their unique cytopathology: infection causes cell enlargement and nuclear lysis, producing membrane-bound vesicles filled with virions that circulate in host hemolymph, giving infected larvae a characteristic opaque, milky-white appearance. The family comprises two genera, Ascovirus and Toursvirus, and transmission typically occurs horizontally through parasitoid wasps that vector virions between hosts.

Etymology

From Ascovirus (type genus, from Greek askos 'bladder, sac' + virus) + -viridae (family suffix for viruses)

Example

Infection of fall armyworm (Spodoptera frugiperda) larvae with Spodoptera frugiperda ascovirus 1a (SfAV-1a) causes retarded growth, reduced feeding, and eventual death; the virus is mechanically transmitted by female braconid wasps during oviposition.

Related Terms

• Ascovirus
• Pimascovirales
• Nucleocytoviricota
• iridovirus
• entomopathogenic virus
• cytopathic effect
• Hemolymph
• parasitoid transmission

Usage Notes

Always capitalized as a formal taxon name. Distinguished from Iridoviridae and other large DNA viruses of insects by the distinctive vesicle formation and wasp-mediated transmission. The term refers to the family rank; individual viruses are called ascoviruses (lowercase) or by their specific epithets. Host range appears restricted to Lepidoptera, with no confirmed infections in arachnids or other arthropod classes.