Usually the aphid vectors cannot overwinter in Alberta and they normally drift in every spring from the United States. These aphids may already be infective they but can also pick up the virus from infected perennial grasses in Alberta. The aphids can remain infectious for life, which is around 40 days. Damage Description Symptoms vary with the host species and the stage of crop development. Infections at the seedling stage may result in death or dwarfing as well as sterile heads.
Leaves turn yellow from the tip down, along the leaf margins or in blotchy patches.
Discolored areas enlarge and progress to the base of the plant. Heads may be wholly or partially sterile. There may also be an increase or decrease of tillers produced by infected plants. Cereal plants infected early in the season may be shaded out by healthy or late infected surrounding plants. Winter wheat seedlings may be 100 per cent infected with BYDV before freeze-up in the fall.