Hickory Trees & Wood Borers

Common Hickory Wood Borers

Some common hickory wood borers include twig and branch purner larvae, lyctid powderpost beetles, hickory spiral borer and a longhorned beetle called the painted hickory borer. Twig and branch purner larvae girdle branches and twigs by gouging a groove around their circumference, causing them to die and fall off the tree. Lyctid powderpost beetles attack hardwood hickory used in home construction. They prefer hardwoods less than five years old, according to the University of Florida Extension. Hickory spiral borers attack every part of the tree but its leaves and makes spiral-shaped burrows within the bark, and painted hickory borers' larvae feed beneath the bark then enter the heartwood. These roundhead borers are more destructive than their flathead cousins, according to the Oklahoma State University Extension.

Look for frass. Frass is the insect's excrement and it will accumulate at the base of the infested tree or around the entrance to the boring tunnels. Frass resembles sawdust. Don't mistake wood borer damage for woodpecker damage---woodpeckers don't leave piles of frass around their holes.

Because many borers and their larvae make their home beneath the bark of the tree, that will likely be the first place you notice damage to a hickory tree. Damage, however, isn't usually perceived until the tree has been significantly stressed, enough to show it outwardly. If you notice that a tree is losing branches or twigs, you may have an infestation of twig and branch pruner larvae, which girdle those parts of the tree, causing them to die. Many borers and their larvae penetrate into the sapwood or heartwood of the tree, disrupting its water and nutrient flow, causing it to die.

Wood borers are protected by the bark of the tree, which prevents penetration of any pesticide. According to the Oklahoma State University Extension, "Once borers enter the cambium, sapwood or heartwood, they are protected from most control efforts. Their presence may remain concealed until it is too late to save trees." The best tactic is to grow healthy, hardy trees that are well -adapted to their location.