n Kentucky there is a complex of aphid species that feeds on wheat. The bird cherry oat, the English
grain (Fig.1), the greenbug, and the corn aphids are the most important species. Their role as vectors of plant viruses, particularly Barley Yellow Dwarf Virus (BYDV), branded them as the key pest on
wheat grain production. These aphid species overwinter as nymphs, and can be active when temperatures are above 45⁰ F. It is known that BYDV infections are more damaging when they occur in early growth stages of the wheat plant. Thus, aphids have more opportunities to infect young plants under this climatological circumstances.