Question
i have two acres of land 40 miles north of houston tx. and have had tremendous problems with carpenter ants eating the insides of the trees out and dropping the wood at the base of the tree. ive been steadily applying insecticed (ortho max bug begone with bifenthrin .0115%) and they still persist. ive also sprayed the malothon by ortho directly. can you suggest anything.

also is there anything specific that i can feed the tree with that will help to mabey regenerate the tree and help it to flourish again. i dont believe the trees are to far gone but a couple have got quite a bit of dead limbs mixed with live branches as well.

Answer
Hi there:
Carpenter ant nests are very common inside trees, especially older trees that are hollow or have a significant amount of decay, dead limbs and branches. The nests are usually in rotted, decayed wood, although some nests may extend into sound heartwood in the center of the tree.

Carpenter ants in trees are not directly harmful to the tree. Control is not essential for the tree's health, as the ants are only taking advantage of an existing situation of soft, weak wood in which to establish their colony. Stress, mechanical injury, environmental conditions, disease or other insects are responsible for killing limbs or sections of the trees in which the ants are able to nest. Once injury has occurred, wood decay can set in if moisture is present; it is the wood decay that gives the 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 inside trees is difficult but can be done as a way to reduce invasion of the ants into adjacent structures. It is also possible for ant colonies located inside trees to form satellite colonies inside a nearby home wall. Available controls are not likely to permanently rid a tree of carpenter ants so retreatment every year or so may be necessary. Dust insecticides containing pyrethroids or carbaryl labeled for use on trees in the landscape are suggested for control. Apply the dust directly into the nest cavity.
Plugging or sealing tree cavities or treating tree wounds with wound dressings is not advised. Such treatments are unnecessary and will not eliminate nor prevent decay or carpenter ant activity. Also, cutting down otherwise viable trees that happen to be infested with carpenter ants is generally not necessary.
As for regeneration of your trees, other than possible fertilzing(after a soil test)and proper watering there is not a lot you can do. Hope this helps,Bill