Branch and twig borers—Scobicia declivis, Polycaon confertus
Adult borers are dark brown beetles, cylindrical in shape
and 0.25 to 0.5 inch long. The immature stage (grub) is
white, fleshy, enlarged just below the tiny head, and appears
legless. It is typically curled
up in a C-shape.
Larvae tunnel in twigs causing dieback. Adults bore into small twigs commonly at bud or spur axils to
lay eggs. This causes twigs or branches to die and leaves to wilt, resembling a blight strike from disease.
If a hole is present, the damage is caused by the borer.
Keep plants vigorous by providing proper cultural control. Prune out dying and dead parts of the tree
and remove or burn all prunings before March, because these are breeding sites for beetles. Keep area
free of prunings and wood cut from ornamentals. Pesticides should not be necessary.
Branch and twig borer adult
Hole in twig from borer