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