FORMALDEHYDE AS AN ANTIVIRAL AGENT AGAINST A GRANULOSIS VIRUS OF PIERIS BRASSICAE

A granulosis virus of Pieris brassicae failed to produce infection in second-instar larvae when applied to the surface of a synthetic diet containing 0.04% w v of actual formaldehyde (H·CHO). On the other hand, tests in which the diet containing formaldehyde was fed to the larvae which had already fed on virus afforded no evidence that it could prevent the development of symptoms. In the case of transovarially transmitted infection, also, the incidence of primary virus disease was as low among larvae fed on diet without formaldehyde as on diet containing formaldehyde. In the case of P. brassicae the low incidence of virus observed among certain stocks feeding on diet compared with sibling larvae on fresh cabbage leaves cannot, therefore, be ascribed to the presence of formalin in the diet. © 1969.