Most fly in the fall. In general, they are moving from drying summer grasses to young fall grasses, including small grains. This movement brings BYDV into a wheat field. Some will make short flights, just a few feet to to a few yards. This moves BYDV to new spots in a field.
Aphids often walk from plant to plant.
This gradually expands the area of an existing population and produces circular spots of infected plants if the virus is present. The earliest infected plants are near the center and the most recently infected ones are near the edges. The spots expand in size over time. Life Cycle Aphid life cycles are very complicated and vary considerably between species and even between individual populations of the same species. The following is a very abbreviated description intended to help understand what is going on in Kentucky s small grain fields.