Hop stunt viroid(HSVd) was detected on symptomless apricot (Prunus armeniaca) samples in Ontario, Canada. Global distribution of HSVd is wide however this is the first report for Canada. The viroid is mechanically transmitted and has a broad host range including other Prunus species, citrus, cucumber and grapevine. The origin and route of entry into Canada are unknown.
For the full story see:
Michelutti, R., M. Al Rwahnih, H. Torres, G. Gomez, M. Luffman, A. Myrta, and V. Pallas. 2004. First record of Hop stunt viroid in Canada. Plant Dis. 88: 1162. Published online as d-2004-0806-01N, 2004.