any of various four-winged hymenopteran insects (esp. families Tenthredinidae and Cimbicidae): the abdomen of the female is provided with a pair of sawlike organs that cut into plants, the eggs being then deposited in the cuts
See sawfly in American Heritage Dictionary 4
noun
Any of various hymenopterous insects, chiefly of the family Tenthredinidae, the females of which have sawlike ovipositors used for cutting into plant tissue to deposit their eggs.