-- The twig pruner occurs throughout the East. It prefers hickory and
basswood but also attacks oaks. Larvae bore into the stems and cut off
or prune twigs, terminals, and branches about .25 to 1 inch (6 to 25
mm) in diameter. Severe pruning adversely affects tree form and the
aesthetic quality of ornamental plantings, and creates clean-up problems.
Insect (figure 27a). -- Larvae are cylindrical, white, and measure
about .5 to .8 inch (12 to 21 mm) long at maturity. Adult beetles are
Injury (figure 27b). -- During the summer, fall, and winter, pruned
twigs (with leaves attached) 12 to 40 inches (30 to 100 cm) long litter
the ground under infested trees. The end of the severed twig presents
a smoothly cut surface. Split the pruned twigs to reveal the larva.
-- Adults emerge during spring and deposit eggs in small twigs. The
larva burrows down the center of the stem and severs the twig, which
falls to the ground, in late summer or fall. Pupation and adult emergence
occur the following spring. There is one generation per year.
-- Collect and burn severed twigs during the fall and winter. Natural
enemies help control the twig pruner.