insect whose female has a saw-like ovipositor for inserting eggs into the leaf or stem tissue of a host plant
source: WordNet 3.0
Any one of numerous species of hymenopterous insects belonging to the family Tenthredinidæ. 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 larvæ resemble those of Lepidoptera.