Naturally occurring IgM antibodies to a small RNA insect virus in some mammalian sera in New Zealand.

Antibodies to cricket paralysis virus were demonstrated in sera from a pig, a horse, and numerous cattle in New Zealand. The reactions in immunodiffusion tests were variable, but significant and consistent reactions were obtained with these sere in virus neutralization assays using Drosophila cells. The sedimentation coefficient of the antibodies was 19S, and their activity was destroyed by treatment with 0.1 M 2-mercaptoethanol, indicating that they were of the IgM class.