Twig pruner larvae feed in the branches of many hardwoods and cut these branches from the trees. Shade and park trees are frequently so severely pruned by this insect that the shape and appearance of the tree is altered. It is not unusual to see the ground thickly strewn with these severed twigs. The twig pruner seldom results in the death of the tree. The thorax is nearly cylindrical.
Legs are present.
The adults fly about the time the oak leaves begin to form, and deposit the eggs near the tip of the twigs in the axil of a leaf. The young larva mines down the stem, increasing in size as it goes, until late in the summer it serves the branch by several concentric cuts from the center outward, except for the thin bark. The larva retreats up the fallen stem and secures itself between two wads of fibrous frass, where it pupates in the fall or early the following spring. The pruning process is not always in itself especially injurious, because when the pruner occurs in only low to moderate numbers, the vitality of the tree is not impaired. The ultimate effects, however, are likely to be more serious, especially further south.