WSMV can survive in a variety of environments as long as a primary or alternative host and the mite vector (Aceria tosichella) are present. It is an obligate parasite and must have a viable host for replication. The virus relies exclusively on its vector for transfer from host to host (Slykhuis, 1955) and survives in non-wheat production areas by using alternative hosts such as a variety of native grasses (Bowden et al., 1991; Christian and Willis, 1993).