The corn armyworm, Spodoptera frugiperda, is a polyphagous insect that causes important economic losses worldwide. Its control with highly toxic chemical insecticides is inefficient given the generation of resistance. Biological control with nucleopolyhedroviruses emerges as an alternative considering the efficacy and high specificity of these agents. However, baculoviruses are affected by environmental conditions, ultraviolet solar radiation being the most limiting factor for field efficacy. For this reason, the present work aimed to determine the susceptibility of a S. frugiperda nucleopolyhedrovirus to type UVA, UVB and UVC monochromatic ultraviolet radiation. Five concentrations of purified virus were exposed to each type of UV radiation over different times for a maximum of one hour. A negative effect of the three radiation types was observed on insecticidal activity, being greatest at higher exposure time and UV radiation energy. These results confirmed the need to develop a formulation which includes solar protectors for ensuring biopesticide efficacy under field conditions.