Apterous: yellow, green or red, cornicles straight, black and reticulated.
Alate: green or red with dark lateral spots, antennae long, black; cornicles medium-length, black, straight and reticulated; cauda long and light-coloured.
Monoecious holocyclic (the second photo shows mating between an alate male and an apterous oviparous female).
Anholocyclic in zones with mild climate.
Poaceae and other monocotyledons.
Colonies of S. avenae proliferate strongly on inflorescences.
S. avenae is the major pest of wheat crops in spring. A strong infestation of these aphids can provoke yield losses of up to 25q/ha through direct damage due to a 1000 grain decrease in the number of grains and weight per head. Moreover, the copious secretions of honeydew foster sooty mould development.
Later-developing infestations (producing pasty textured grain) jeopardize yields less than the earlier ones (head formation, flowering).
In addition, this species is a good vector of viruses and especially barley yellow dwarf (BYDV, PAV and MAV).