Twig beetles are insects of conifer trees, principally pines. Beetles are tiny (1 – 3 mm) long and dark brown in color. Twig beetles may become active in March and persist through October. There are 2 to 4 insect generations per year.
These tiny wood boring insects are found in smaller twigs and branches with thin bark. Large branches are not affected. Beetles infest just underneath the bark producing galleries and mining the tree cambium. Reddish tan sawdust is present, but little if any pitch is produced.
Twig beetles are usually a secondary pest found in dead and dying twigs. Trees that are drought stressed or have suffered a root injury are more prone to damage. Recently transplanted trees may be killed by twig beetles.
Increasing plant health and vigor with proper cultural practices is the first line of defense. Sanitation is also important. Do not leave freshly pruned live wood (slash) around other conifer trees. Remove and dispose of pruned branches promptly.
Spraying with insecticide may be warranted and is especially important with recently transplanted trees. Two or 3 sprays evenly spaced sprays during the season with insecticides including the active ingredients carbaryl (Sevin) and permethrin (Eight) will control twig beetles. Read insecticide label directions before making any applications.