How Wood Boring Insects Damage Your Trees
June 8, 2020
Wood boring insects can do damage to your tree that you may never see. Did you know that there can be damaging insects lurking below the surface of your tree’s bark? Wood boring insects come in a variety of forms and do a variety of damage to your trees.
Boring insects originate in the beetle, wasp, and moth families. The adult insects either burrow into tree bark and lay their eggs in the tree tissue, or lay them in cracks in bark. Once the eggs hatch, the real damage starts.
Borer larvae will devour wood as they tunnel throughout the tree, damaging the tree’s ability to transport water and nutrients and leaving them structurally weak. You will often see sawdust at the base of trees, or small exit holes produced when adult borers exit, in trees with a borer infestation.
These destructive insects tend to choose weakened, old or damaged trees – further weakening them to the point of death. Borer insects are difficult to control since usually an infestation goes unnoticed until it is too late. Once an infestation is found, effective treatments are limited.
Because of the damage they can do in widespread areas, especially in the case of Emerald Ash Borers, routine scouting is performed by arborists and the Department of Agriculture. Preventative treatment and tracking movements of the insects can help to control the spread of wood boring insects.
Wood Boring Insects Common to North Texas:
Emerald Ash Borer (EAB): There is no shortage of press about this invasive insect causing major destruction across the United States. The bright green beetle burrows in Ash trees and quickly kills them. EAB was found in Texas in 2016 and in Fort Worth in 2017. EAB is especially dangerous to ash populations because it attacks healthy trees and since the bright green, metallic beetle is a non-native pest, they are no natural insect predators.
Redheaded Ash Borer: A very common borer in North Texas that feeds on ash as well as oak, elm, and even grape vines. RABs specifically like to breed in dying or newly cut logs. The adult insect is ½” to 5/8” and emerges in the spring.
Red Oak Borer: This beetle attacks oak and maple trees. They lay their eggs in crevices in the bark; the larvae then tunnel into the wood. Red Oak borers cause more issues for the lumber industry because they prefer freshly cut wood. This insect is difficult to spot because it’s coloring blends with the wood color.
Cottonwood Borer: This particular borer likes to lay its eggs at the base of trees, where they hatch and burrow into the trunk, where larvae may feed for 1-2 years before pupating and emerging as adults. Because this pest attacks at the soil line, girdling can become a major issue for cottonwood, popular and willow trees; creating entry points for the larvae. The large (1.5”) black & white patterned beetles are easy to spot.
Locust Borer: This bright yellow & black patterned beetle only attacks black locust trees. The tunneling larvae weaken branches causing trees to be susceptible to breakage due to wind. Adults are seen emerging in August.
If you notice any of these insects in your trees, or notice any other signs of borer damage - such as sawdust or small holes -please contact a certified arborist immediately for a professional identification and treatment plan.
Posted: June 8, 2020