Virus diseases have been reported from more than 800 species of insects and mites. Isolates of the baculovirus and cytoplasmic polyhedrosis virus groups have biological properties which should lead to their successful use as microbial control agents in integrated pest management programmes.
These viruses infect the larval stages of many lepidopterous and hymenopterous pests, producing a chronic or lethal infection and the release of large quantities of relatively stable infective inclusion bodies (IBs).
The IBs serve as the means by which the viruses are transmitted and persist outside the host.
Younger larvae are more susceptible to infection than older stages, and this difference influences the timing of application and doses of virus needed for practical pest control.