Are termites really attacking your tree?
Finding termites in a tree is alarming, but the tree is not always the victim. In most places, termites feed mainly on dead or decaying wood. They often move into dead limbs, stumps and hollow, decayed trunks. In that case, termites are a sign that decay was already present, not the original cause of the problem.
There are exceptions. Some species, such as Formosan subterranean termites in the southern United States, are known to infest living trees and can hollow out the heartwood. University extension programs in affected areas have run tree-treatment efforts for this reason.
If you are unsure what you have, a licensed pest control professional or certified arborist can identify the insect, which matters because the treatment depends on the species.
Signs of termites in a tree
- Mud tubes: pencil-wide tunnels of soil running up the bark from the ground
- Hollow or soft wood: wood that sounds hollow when tapped, or that feels spongy under the bark
- Frass or debris: small pellets or sawdust-like material near holes or at the base (some termites leave pellets, others leave very little)
- Swarmers or discarded wings: winged termites emerging, often in spring or after rain, and small piles of wings near the trunk or window sills
- Carton material: a papery, brownish, chewed-wood-and-soil material in cavities or exit points, associated with some species
Tapping the trunk and looking for tunnels beneath loose bark can help, but be careful with a large tree that may have structural weakness.
Termites or carpenter ants?
The two are often confused. Carpenter ants excavate wood to nest, not to eat it, and they leave clean, smooth galleries with coarse sawdust. Termite galleries often look rougher, with soil or mud. Ants have a narrow waist, elbowed antennae and, in winged forms, front wings longer than the back; termites have a thick waist, straight beaded antennae and wings of nearly equal length. Because treatments differ, confirm the insect before spending money.
Do termites eat maple and other living trees?
Termites can be found in maples and many other tree species, mostly where wood is dead, wet or decayed. A healthy maple is not usually a prime target, but decayed sections of any species can host termites. Trees with wounds, large pruning cuts, or hollow trunks are easier for them to enter. Being careful about holes and cavities in tree trunks is therefore part of the picture.
Why termites in a tree matter for your house
Termite colonies do not stay in one piece of wood. A colony in a stump or tree near a building can forage through the soil toward wooden structures, and tree roots or stumps that rot over time may add to the wood supply. If a tree near your home has termites, have the house inspected. Keep firewood, wood mulch and wood debris away from the foundation. Our cedar mulch around fruit trees article covers how mulch and termites relate.
How to treat a termite-infested tree
Stump and dead wood
- Remove dead branches and limbs, and dispose of them away from the house
- Consider stump removal or grinding if the stump is near a building
- Do not stack infested wood against structures
Living trees
Options for living trees are limited, and results vary. A tree can often survive if the main heartwood is still solid and the infestation is caught early, but one with extensive hollowing may need to be evaluated for safety.
- A licensed pest control operator can apply a termiticide to the soil around the base or inject treatments into infested cavities, following label directions
- In areas with Formosan termites, professionals may use baits or targeted treatments of the tree
- A certified arborist can check structural soundness and advise whether pruning or removal is better
Pesticide products for termites are regulated and many are intended for professional use. Follow the label closely, keep them away from water sources and pets, and consider hiring a licensed applicator rather than treating a large tree on your own.
Smells, natural enemies and home remedies
Online lists often claim that certain smells repel termites, such as orange oil, neem oil or vinegar. Some of these products can kill termites on contact in the right conditions, but there is little evidence they eliminate a whole colony hidden inside a tree or underground. Ants and some other insects prey on termites, but you cannot rely on them to remove an established colony. For an active infestation, professional treatment is generally the safer path.
When the tree is a hazard
Termites often indicate decay, and a tree with a hollow or decayed trunk can fail without much warning. Signs of concern include a leaning trunk, dying branches, large cavities, and fungal growth at the base, which can also accompany root rot. Keep people and vehicles away from a questionable tree and have an arborist assess it.
Prevention
- Keep mulch thin and away from the trunk and from building walls
- Avoid leaving stumps, buried wood or heaps of lumber near the house
- Prune correctly and avoid leaving large wounds or stubs
- Fix drainage so soil near the trunk does not stay soggy
- Have a pest professional do regular termite inspections, especially in warmer regions