What are EPV?

Insect poxviruses or entomopoxviruses (EPV's) infect insects from the following five insect orders: Coleoptera (beetles), Lepidoptera (moths and butterflies), Orthoptera (grasshoppers and crickets), Diptera (flies), and Hymenoptera (bees and wasps). The grasshopper EPV's are found in the genus Entomopoxvirus B, which also includes viruses from Lepidoptera and Orthoptera (Esposito 1991). All grasshopper viruses are physically similar and have roughly the same deoxyribonucleic acid (DNA) size. They differ from EPV's in other insect orders and other animal poxviruses. Indeed, there is no evidence to suggest any close relationship or similarity between grasshopper entomopoxviruses and other viruses of vertebrate or invertebrates (Langridge 1984).

Virus particles are embedded in a crystalline proteinaceous matrix referred to as an occlusion body (OB). OB's vary in size from 3 to 12 microns (mm) in diameter and may each contain up to several hundred virus particles. Twelve mm equal about 1/20,000th of an inch. OB's offer the virus particles some protection from environmental conditions and are thought to be responsible for transmission of a virus from one grasshopper to another. When OB's are ingested by a grasshopper, the virus particles are released and penetrate through the digestive tract into the body of the grasshopper. Infection by grasshopper EPV's appears to be restricted to the fat body, a tissue which is used to store food reserves and metabolize food. After the virus particles enter a fat body cell, they replicate and pack the cytoplasm with new OB's that contain virus particles. Virus particles will also spread to other fat body cells until nearly all the cells in the fat body are infected with virus (Henry et al. 1969, Granados 1981).

Epstein-Barr Virus?