Bird-Cherry Oat Aphid

Rhopalosiphum padi

Two bird-cherry oat aphids
Two bird-cherry oat aphids. Photo courtesy of Frank Peairs. Licensed under CC BY 3.0.
Bird-cherry oat aphids are a tiny pest of small grains such as wheat and oats.
Bird-cherry oat aphids are typically olive green in color with the posterior being more red or brown. Under very warm conditions the adults are paler in color. Nymphs are similar in shape to the adults but are yellow-green in color.
Colony of bird-cherry oat aphids
Colony of bird-cherry oat aphids. Photo courtesy of Frank Peairs. Licensed under CC BY 3.0.
Bird-cherry oat aphids cause damage by sucking plant juices from developing plants, weakening the plant. They are also a vector for barley yellow dwarf virus.
Insecticides are available for controlling bird-cherry oat aphids, although natural predators usually keep populations under control. Always read and follow all label instructions.