Sawflies (Suborder Symphyta) are members of the order Hymenoptera. These insects are almost completely herbivorous, with the larvae hatching and maturing in a host plant. Sawflies must lay their eggs in the tissue of host plants, and to do this they use an egg-laying device (an ovipositor) that resembles a saw. The female sawfly uses the ovipositor as a drill to open up plant tissue and lay eggs inside the plant.
There are two main differences between the sawflies and the other members of the Hymenoptera. The Hymenoptera excluding sawflies is referred to as the Apocrita. These insects are wasps and bees with a constricted abdomen. The Apocrita is further divided into the Aculeate wasps and the parasitoid wasps. In Aculeates the ovipositor is a stinger: it has been co-opted for venom delivery in some wasps, either for defense against predators or in the incapacitating of prey (i.e. spider wasps). Parasitoid wasps use their egg-laying device to lay eggs on living prey, often having very long, thread-like ovipositors.