Inactivation of nuclear polyhedrosis virus (Baculovirus subgroup A) by monochromatic UV radiation

Area of Science:

• Entomology
• Virology
• Photochemistry

Background:

• The Douglas-fir tussock moth, Orgyia pseudotsugata, is a significant pest in forestry.
• Nuclear polyhedrosis viruses (NPVs) are common pathogens used in biological control of insects.
• Understanding virus inactivation mechanisms is crucial for optimizing biocontrol strategies.

Purpose of the Study:

• To investigate the efficacy of monochromatic ultraviolet (UV) radiation in inactivating the occluded nuclear polyhedrosis virus of Orgyia pseudotsugata.
• To determine the relationship between UV wavelength and the fluence required for virus inactivation.

Main Methods:

• Exposure of occluded Orgyia pseudotsugata NPV to monochromatic radiation at specific wavelengths (290, 300, 310, and 320 nm).
• Quantification of virus inactivation based on exposure to varying light fluences.
• Analysis of dose-response curves to determine inactivation kinetics.

Main Results:

• All tested UV wavelengths (290-320 nm) demonstrated the capacity to inactivate the occluded nuclear polyhedrosis virus.
• A clear trend was observed where increasing wavelength necessitated significantly higher fluences for effective virus inactivation.
• The data suggest a wavelength-dependent susceptibility of the virus to UV radiation.

Conclusions:

• Monochromatic UV radiation is a viable method for inactivating Orgyia pseudotsugata NPV.
• UV inactivation efficacy is inversely related to wavelength, with shorter wavelengths being more potent.
• These findings have implications for the storage, formulation, and application of baculovirus-based biopesticides.