Several aphid species feed on the leaves and grain heads of wheat. Adult aphids are only about 1/8 inch long, and may or may not have two pairs of nearly transparent wings. These pests are significant in that they are capable of transmitting diseases, such as barley yellow dwarf (BYD) virus, in addition to the damage inflicted by their feeding habits.
The bird cherry-oat aphid is dark green and the primary species that transmits BYD. It is usually the most common species observed in wheat.
The English grain aphid is pale green with black antennae and cornicles (‘tailpipes’), which are longer than the antennae and cornicles of other aphid species normally observed in wheat.
The greenbug is pale green with a dark green stripe down the back of the wingless form. The tips of the legs and cornicles are black, and the antennae are mostly black.
The corn leaf aphid is bluish-green with black legs, cornicles and antennae.
The rice root aphid occurs on the roots of wheat and is also known to transmit BYD.