EFFECT OF ULTRAVIOLET RADIATION OF KNOWN WAVELENGTHS ON A GRANULOSIS VIRUS OF PIERIS-BRASSICAE

When the known granulosis virus of Pieris brassicae was exposed to ultraviolet radiation from a germicidal lamp (predominantly 253.7 nm) it was much more rapidly inactivated in pure films than in films of crude virus, where colored and solid impurities were present. In both cases inactivation occurred more rapidly in wet films than in dry films. When the inactivating effect of UV of different wavelengths was compared, using a highly purified virus preparation, it was found that this decreased progressively as the wavelength was increased but that inactivation was still brought about by, at any rate, the shorter wave ultraviolet radiation (291.5-310 nm) present in sunlight as it reaches the earth. Owing to the lengthy exposures involved the effect of the longer wave ultraviolet (320-380 nm) was not determined. © 1969.