Exit Holes
Small holes in the bark where adults have emerged. Depending on the species, holes may be round, oval, or D-shaped.
Tree Borers in Texas: Signs, Treatment & Prevention Guide
Homeowner Tree Care Guide
Understanding Tree Borers
Tree borers are among the most destructive problems a tree can face. Since the larvae feed beneath the bark, damage is often hidden until it's too late.
What borers are
Not just one insect
“Borers” refers to a group of beetles and moths whose larvae live inside trunks, branches, or roots. They are difficult to spot early because most of the damage happens under the bark.
Why they matter
They feed where it counts
Borer larvae tunnel into the cambium, disrupting the movement of water and nutrients through the tree. Heavy infestations can weaken, girdle, or kill a tree over time.
Who is most at risk
Stressed trees
Borers commonly attack trees already struggling from drought, transplant shock, root stress, soil compaction, bark injury, or other underlying issues.
Important note
Not every hole, dead branch, or declining canopy means borers. Correct identification matters because treatment timing, product choice, and expectations can vary by tree species and by the specific insect involved.
Signs to look for
Because borer larvae stay hidden beneath the bark, the best way to catch a problem early is by looking for the evidence they leave behind.
Frass or Sawdust
A sawdust-like material can collect in bark crevices, on limbs, or around the base of the tree as larvae feed and tunnel inside.
Oozing Sap or Pitch
Some trees try to push insects out by bleeding sap or pitch from entry points. Fresh gumming or bleeding on the trunk can be an important clue.
Woodpecker Activity
If woodpeckers are working one area of the trunk repeatedly, they may be hunting larvae beneath the bark. Bark flecking or probing can be a strong warning sign.
Other signs of borers
In addition to visible bark symptoms, trees with borer pressure often show decline in the quality of their canopy.
- Upper canopy thinning
- Premature yellowing or browning
- Dieback on individual limbs or branch tips
- Weak overall growth
Important takeaway
The borer is often not the first problem. It is commonly the result of a tree already under stress. That is why watering, mulching, root-zone care, and reducing bark injury are such a big part of tree care!
Prevention is the best defense.
Water deeply
During hot, dry weather, deep watering helps maintain sap flow and supports the tree’s natural defenses.
Mulch correctly
Apply 2 to 3 inches of mulch over the root zone, but keep it pulled back from the trunk to avoid moisture buildup against the bark.
Avoid extra stress
Prevent mower and weed eater damage, avoid unnecessary bark wounds, and don’t over-prune stressed trees.
If you already have an infestation
- Systemic treatment: Some cases may be treated with a systemic insecticide, but product and timing depend on the tree and the insect.
- Pruning: If damage is isolated to smaller limbs, pruning out affected wood may help reduce spread.
- Removal: If the trunk is heavily infested and the canopy is badly compromised, removal may be the safest option.
When to get help
- Multiple holes are appearing on the trunk or major scaffold limbs
- Sap is bleeding from several spots
- You see fresh frass or sawdust
- Sections of the canopy are declining
- You are not sure whether the issue is borers, drought stress, disease, or something else
Need help with a stressed tree?
If you purchased your tree from The Tree Place and it is showing signs of stress, fill out the support form and include photos of the trunk, foliage, and any holes, frass, sap, or dieback.
- Include clear close-up photos of the trunk
- Include a wider shot of the full tree
- Show any holes, sawdust, sap, or dead limbs
- Add details about watering and when symptoms first appeared