Landscaping Q&A with Bruce Kreitler

A common question is "I have ants in my tree. Should I do something about that and are they hurting my tree?"

Often this question is phrased just a little differently, more along the lines of "I have ants in my tree and I want them gone."

While nobody that I know has ever been particularly fond of ants, ever since fire ants invaded the state of Texas, any residual tolerance of ants is pretty much gone.

While lots of different kinds of these insects will crawl up, on, and around trees, for the most part only "wood ants" will actually live inside the trunk and branches. Almost every time, what they are doing in your tree is just using decayed areas to tunnel through and create galleries to live in.

Even though we label them wood ants, they actually are eating something besides the tree. The small sawdust (frass) that you find below their entry holes is just material that was already dead or decayed which they moved out of the way to make living area. If you inspect that frass very closely (I know, too much time on my hands) you will usually find pieces of insects and/or vegetation that would show you what they actually eat.

Wood ants create room in dead or decayed wood to live and nest in while they forage outside of that nest. In this manner they are very similar to the ants that live in the ground. This is seldom harmful to the tree because even though the wood that the ants are in is unhealthy and decayed, the ants aren't causing it. In fact, I regard wood ants in a tree as a symptom of decay.

As a tree person, I don't get really worked up about wood ants. When I see them I'm much more interested in why a tree has enough decay to attract them than I am in the actual ants themselves. Where they can be a real problem is when there are enough of them in a nest to start spreading out.

They can use proximity to houses as a good launching point for moving into a structure. While the dead wood that they tunnel through in a tree probably isn't that important, the dead wood that is the interior structure of your house is pretty critical, and it doesn't need to be infested with tunneling insects.

Since they aren't normally feeding on the living part of a tree, treating the tree itself to get rid of ants probably won't work too well. My usual advice to people that need to get rid of ants living in a tree is to either purchase an over-the-counter "ant poison" or call in an exterminator to deal with them.

How can i kill Texas fire ants? | Pest Control Buzz Daily

Killing is easy part, keeping them out of your yard is harder. I use Orthene white powder to kill a nest top but you have to watch for where they pop up again and keep applying. The nests have deep chambers where the queen and eggs lie and if poison is applied usually they just move underground and rebuild the nest top somewhere else. By continual reapplying of the Orthene you might be able to run them out of your yard. There are some long lasting bait types now that I hear are good but I do not have any experience using them.

if you mean get rid of the immediate mounds drenching with a liquid insecticide would be the fastest remedy. The Ortho Orthene Fire Ant powder is also very effective but it does have an odor , it kills the mound in 24 hours. To help keep them away broadcast treatments of either Amdro or Logic twice a year will help. Amdro can be used alone for the mounds but it will take a week or more to get result, Logic does not kill them but is a growth regulator so it can take 2 weeks or more to kill an active mound.

The fire ants

LIFE

The fire ant wars, nature, science, and public policy in twentieth-century America

Fire ants

Texas Monthly