Nuclear Polyhedrosis Virus

The nuclear polyhedrosis virus (NPV), part of the family of baculoviruses, is a virus affecting insects, predominantly moths and butterflies. It has been used as a pesticide. The polyhedral capsid from which the virus gets its name is an extremely stable protein crystal that protects the virus in the external environment. It dissolves in the alkaline midgut of moths and butterflies to release the virus particle and infect the larva. An example of an insect that it infects is the fall webworm. NPV was once listed by the International Committee on Taxonomy of Viruses as a subgenus of Eubaculovirinae, but the term now refers to 35 species of the genus Baculoviridae—mostly alphabaculoviruses, but also one deltabaculovirus and two gammabaculoviruses. Symptoms of NPV infection include: The virus enters the nucleus of infected cells and reproduces until the cell begins to produce crystals in the fluids of the host. These crystals can transmit the virus from one host to another. The host becomes visibly swollen with fluid containing the virus, and eventually dies, turning black with decay.