Flat-headed Borers

Flat-headed borers are a group of beetles that are known for their ability to damage and kill trees and shrubs in Central Texas. These insects are named for their flat and elongated bodies, and they are known to infest a wide range of hardwood and coniferous trees.

Flat-headed borers primarily attack trees that are already stressed or weakened by other factors, such as drought, disease, or injury. They enter the tree through wounds in the bark and then tunnel into the sapwood and heartwood, where they feed and lay eggs. This feeding and tunneling causes damage to the tree’s internal structure, which can lead to wilting, dieback, and ultimately death of the tree if the infestation is not controlled.

To control flat-headed borers, a combination of pesticides and cultural practices can be used. Pesticides that are effective against flat-headed borers include neonicotinoids, such as imidacloprid and dinotefuran, as well as pyrethroids, such as permethrin and bifenthrin. These chemicals can be applied as a soil drench, trunk injection, or foliar spray, depending on the specific product and the stage of infestation.

It’s also important to focus on cultural practices that help to maintain the health and vigor of trees, such as proper irrigation, fertilization, and soil management. Minimizing mechanical injury to the bark of the tree, and avoiding soil compaction around the base of the tree is also important. These actions can help reduce the susceptibility of the trees to flat-headed borer attack.

In addition, certain types of natural predators and parasites of flat-headed borers, such as parasitic wasps and nematodes, can also provide biological control. Identifying and protecting these beneficial organisms is an important part of an integrated pest management strategy.


You can identify if your tree is infested if you see small holes appearing in the bark of your tree. If you see any holes in your tree, it is often a good idea to have an Arborist assess the issue.

Author: Andrew Anstrom
Board Certified Master Arborist