Cephus cinctus, also known as wheat stem sawfly,[1] is a slow flying, yellow and black coloured, destructive pest found mainly in western North America.

[2][3] Wheat stem sawflies grow to a length of 7 to 12 mm, with males being smaller than females.

[3] After mating, female wasps lay eggs in plant stems, usually before the grass head has emerged.

[2][3] In autumn, the larva plugs the exposed end of the stem and builds a cocoon in which it overwinters.

[2][3] The species has a wide host range that includes all large-stemmed grasses except oats (Avena sativa).