Field and glasshouse experiments with two raspberry viruses transmitted by Amphorophora rubi Kalt. showed that raspberry varieties differed greatly in the frequency with which plants became infected. Of the varieties tested, Norfolk Giant seemed the most resistant and Lloyd George the most susceptible, but raspberry plants are relatively resistant to infection and both viruses spread only slowly, even in Lloyd George. Spraying plants of this variety with systox decreased the population of A. rubi more than by spraying with DDT emulsion or parathion; spraying with systox also appeared to decrease the spread of veinbanding virus.