Wheat Stem Sawfly (Hymenoptera: Cephidae): Damage and Detection

The wheat stem sawfly, Cephus cinctus Norton, continues to be a threat to spring wheat production in the northern Great Plains. Winter wheat has also recently come under attack. Losses from lodging can be reduced by early harvest of heavily infested fields. Infestations can be detected by the presence of dark stem spots which are caused by boring larvae. Head weights of infested winter wheat plants were reduced by 2.8-10%. Infestation rates were higher in larger diameter stems, which also could produce the heaviest heads. Solid-stemmed wheat lines were less vulnerable to larval damage.