 The trait of hypovirulence could be transferred from an avirulent strain to a lethal strain through anastomosis, the fusion of hyphae.It was later discovered that this attenuated virulence was due to infection by a dsRNA mycovirus, "Cryphonectria hypovirus 1" (CHV1).Considering the nature of hypovirulent strains, there has been a strong interest to use them to manage lethal "C. parasitica" strains.