Sawfly, any of a group of four-winged insects. The name sawfly comes from the shape of the ovipositor (the egg-laying organ of the female). The ovipositor usually has rows of toothlike ridges and somewhat resembles a saw. The female uses the ovipositor to make slits in various plant parts where she lays her eggs.

Sawflies range from 1/4 inch to two inches (6 mm to 5 cm) in length. Many species have bodies of red, green, or yellow. Although the adult sawfly is relatively harmless, the caterpillarlike larvae of some species cause much destruction, especially to forests and cultivated plants Spraying with various insecticides is usually an effective means of control.

Sawflies make up several families of the order Hymenoptera. The majority of sawflies are of the family Tenthredinidae.

SawfliesSawflies lay their eggs in the leaves and stems of plants and trunks of trees.