n. (Zool.) Any one of numerous species of hymenopterous insects belonging to the family Tenthredinidae. The female usually has an ovipositor containing a pair of sawlike organs with which she makes incisions in the leaves or stems of plants in which to lay the eggs. The larvae resemble those of Lepidoptera. [ 1913 Webster ]

. (a) A small European sawfly (Cephus pygmaeus) whose larva does great injury to wheat by boring in the stalks. (b) Any of several small American sawflies of the genus Dolerus, as Dolerus sericeus and Dolerus arvensis, whose larvae injure the stems or heads of wheat. (c) Pachynematus extensicornis, whose larvae feed chiefly on the blades of wheat; -- called also grass sawfly. [ Webster 1913 Suppl. ]