Sawfly is an insect related to ants, bees, and wasps. Sawflies lay their eggs in the leaves and stems of plants and trunks of trees. Adult females have a sawlike organ that slits the plant tissue and pushes the egg inside. Most immature sawflies resemble caterpillars but have more legs along their abdomens. Some sawfly caterpillars gather in large numbers and may form galls (swellings) on plants. Adults have four membranous wings.
The most destructive North American sawflies are those that attack pine, fir, larch, and spruce trees. Other important species damage garden roses, currant bushes, wheat stems, cherry and pear trees, and birch and elm trees.
