Question
150 year old live oak
Thank you for all of the wonderful information in your article.
I recently spotted carpenter ants in my 150 yr old live oak on Topsail Island, a barrier island in North Carolina [photo attached]. Should they be left to keep adding protective enzymes or should a deterent be used to prevent further holes?
If so, what would be an environmentally respectful detterent? I know of some products made with cedar oil available in my area.
Appreciativley,
Chris Mudarri
AnswerCarpenter ants nest in trees in one of two situations: 1) in rotted, decayed wood or 2) in the center heartwood section of the tree. In neither case are they harmful to the tree. Control is unnecessary for the tree's health, as the ants are taking advantage of preexisting soft, weak wood to establish their colony. Insects, disease, or environmental conditions such as drought are often responsible for weakening and killing limbs or sections of trees. This allows wood rot to set in, which results in wood decay, giving carpenter ants the opportunity to colonize the tree. Carpenter ants use knots, cracks, holes, and old insect tunnels to gain access to these areas.
Control of carpenter ants in trees is warranted if there are indications that ants are entering homes from colonies in trees. If there is evidence of this, the best control is to bait the colony.
Treating the Colony: Because carpenter ants live in colonies, a treatment which targets the colony will be most effective. Finding the colony is important. Look for the piles of sawdust to locate the entrance. Another method to find the colony is to watch the movement of foraging ants. They are most active at night. Inspect the entire structure and surrounding grounds, because the nest may be outdoors.
Once you find the colony, control strategy depends on where it is. If the colony is in a tree, you can use a dust insecticide (such as Sevin?or rotenone) labeled for use on trees in the landscape. Apply the dust directly into the nest cavity.
If the colony is in a wall void, you may need to place an insecticide inside the wall. Do not use liquid insecticides inside wall voids. Introduce the dust into the nest through the entrance hole using hand duster with a tube with a tip which fits snugly in the entrance. It may be necessary to enlarge the hole to fit the duster. You can make a duster from a flexible plastic bottle equipped with a tube tip. An old mustard or catchup bottle might work for this use. Fill the bottle no more than one-third full, insert the tip in the entrance hole and inject the dust by alternately squeezing and releasing the pressure on the bottle. Unfortunately, there aren't very many over-the-counter dust products available for homeowners. It may be money well spent to hire a pest control professional who has a greater arsenal of products at his/her disposal and proper application equipment.
Dust formulations registered for use in and around the home include Drione?(pyrethrins), Tempo?(cyfluthrin), Deltadust?(deltamethrin). These are marketed for the professionals and not readily available in retail outlets. Another useful dust formulation is Apicide?(carbaryl). It is a product made to control bees and wasps in wall voids, but, because it is labeled for wall void treatments, it can be used for these situations. It is important to make sure these wall void treatments won't come into contact with humans or pets. Be sure to store any leftover insecticide in its original container with the label intact and throw away the make-shift duster so it doesn't get used around food.
