Predators such as ladybird beetles, lace wings, and Nabid bugs will typically keep aphid populations below economic thresholds. It is very rare to have aphid populations without predators feeding on it. Maintaining untreated refuges without insecticides may conserve natural enemies and contribute to natural control.
For EGA, the cost of spray treatments will be often more that the dollar cost of damage if natural enemies are destroyed in the spray process. It is hard to pay for a spray with soft white spring wheat prices and obtain a yield increase.
For the bird-cherry oat aphid, seed treatments with an aphidicide will help reduce populations. Foliar sprays are less effective. Treating bird-cherry oat aphid will help control barley-yellow dwarf virus.