Abstract:

The optical brighteners were recently found to enhance the biological activity of viruses against insects of economic importance.The chemicals,which are stilbenes,improve the ability of a virus to infect and kill its hosts and to act as a UV protectant.Depending on the host-virus combination,the brighteners were shown to reduce the amount of virus required to kill(LC₅₀) and(in some instances)the time required to kill(LT₅₀).The righteners were also shown to cause lethal virus infections in insects harboring sub-lethal amounts of virus.In addition,the host range for a given virus might be enlarged.The brighteners had the potential to be very useful as a component in virus formulations for the control of insect pest populations.Whereas the site of action(insect midgut) was known,the mode of action was not yet fully understood.Additional research in this area will lead to a greater understanding of the mechanisms and will result in getting new methods for biocontrol.The present paper reviews the research on optical brighteners as enhancers,and the possible problems and applications for field operation.For example,formulations containing brighteners would be most suitable to control forest insect pests without damage to the environment.

Key words: Optical brightener, Insect virus, Enhancement