Flatheaded & Roundheaded Borers

What it looks like

Look for D-shaped or round exit holes in the bark, along with bark cracking or staining. Affected trees often show dieback starting at the top of the canopy or on the sun-exposed side.

Often mistaken for: General drought stress or other trunk damage

When it shows up in the Triangle

Adults are active in spring and summer, laying eggs on sun-scalded bark, fresh wounds, or drought-stressed trunks.

Where you’ll see it

Landscape trees like maple, oak, and dogwood — especially recently transplanted or drought-stressed trees.

What you can do

• Water new or stressed trees consistently, especially in the first 2-3 years after planting
• Avoid wounding the trunk with mowers, string trimmers, or over-pruning
• Don't over-prune in ways that expose bark to sun scald
• Keep mulch around the base to moderate soil temperature and moisture
• Watch for exit holes, bark damage, or canopy dieback and address tree stress early