wheat sawfly

from the GNU version of the Collaborative International Dictionary of English.

• A small European sawfly (Cephus pygmæus) whose larva does great injury to wheat by boring in the stalks.
• Any of several small American sawflies of the genus Dolerus, as Dolerus sericeus and Dolerus arvensis, whose larvæ injure the stems or heads of wheat.
• Pachynematus extensicornis, whose larvæ feed chiefly on the blades of wheat; -- called also grass sawfly.