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Submitted to: Journal of Entomological Society
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/9/1998 Publication Date: N/A Citation: N/A Interpretive Summary: One of the limitations of insect pathogenic viruses as biological control agents for insect pests of forest and agricultural crops is the rapid inactivation of the viruses by sunlight or ultraviolet light. In recent years a group of chemicals, fluorescent brighteners or optical brighteners, which absorb energy from ultraviolet light and emit it as visible light, have been studied for their ability to protect insect pathogenic viruses from ultraviolet light. Certain of these chemicals were found to enhance infectivity of the viruses even beyond protection from ultraviolet light. This article reviews the literature on enhancement of infection of insect pathogenic virus by fluorescent brighteners. Although the mode of action is not fully understood enhanced infectivity has been demonstrated for 14 different viruses representing 4 different families. The enhanced infectivity generally resulted in earlier mortality and in some cases extended infectivity of the virus to older larvae, which would be beneficial for biological control. Thus if proper formulations can be made, the fluorescent brighteners have the potential to increase the effectiveness of certain insect pathogenic viruses for biological control of certain lepidopteran pests of forest and agricultural crops. Technical Abstract: Fluorescent brighteners or optical brighteners, chemicals that absorb energy from ultraviolet light (UV) and emit it as visible light, have been studied as UV protectants for entomopathogens to extend their effectiveness in the field as biocontrol agents. Some stilbene fluorescent brighteners have been demonstrated both to provide some protection from UV degradation and to enhance infectivity independently of the UV protection for several entomopathogenic viruses. Although the mode of action of this enhanced infectivity is not fully understood, enhanced infectivity of 10 nucleopolyhedroviruses and a granulovirus (Baculoviridae), a cypovirus (Reoviridae), an iridovirus (Iridoviridae), and an entomopoxvirus (Poxviridae) has been demonstrated. The enhanced infectivity produced by the fluorescent brighteners generally resulted in earlier mortality and in some cases extended infectivity of the virus to older instars. In a few cases the host range was extended, i.e., viruses which were not infective for a particular species under normal conditions were infective with the addition of a fluorescent brightener. Thus, if proper formulations can be made, the fluorescent brighteners have the potential to increase the effectiveness of certain entomopathogenic viruses for biocontrol of certain lepidopterous pests of forest and agricultural crops. |
