The inactivation of the nuclear polyhedrosis virus of Trichoplusia ni by gamma and ultraviolet radiation

The activity of the nuclear polyhedrosis virus of Trichoplusia ni was reduced by 90% when exposed as an aqueous suspension of polyhedra to a dose of 3 × 105 rads of gamma radiation. A dose in excess of 1 × 107 rads completely inactivated the virus in suspensions. The virus was more readily inactivated when exposed as dry deposits of polyhedra than as aqueous suspensions. Bacterial contaminants in the viral suspensions were more sensitive to gamma radiation than was the virus but the virus was the more sensitive to ultraviolet light.