CARPENTER ANTS

Background shows a common site for damage by this pest. Insert depicts the insects and their damage (natural size): a, larvae, b. pupa, cocoon removed; c. worker; d. winged female; e. shredded frass; which is pushed from the galleries.

CARPENTER ANTS

Carpenter ants nest in wood. They are a pest in dwellings, utility poles, posts, and tree cavities. In most sections their damage is restricted to minor parts of buildings; thus their injury is less important than that caused by termites.

Carpenter ants seek soft wood (particularly wood that has weathered and begun to decay) to make cavities in which to rear their young. They may be found in porch columns and roofs, window sills, foundation plates, and logs of cabins. The ants do not eat wood. They simply eject it in fibrous shreds as they remove it while constructing their chambers. They feed on honeydew obtained from aphids and scales and on animal remains and plant juices.

The chambers of carpenter ants are clean and are cut across the grain of the wood. Piles of shredded fibers also occur on the outside of infested wood. Wood damaged by termites is characterized by stained, grayish chambers running with the grain. Also, termites eat the wood as they remove it in extending their galleries.

A colony of carpenter ants consists of workers of various sizes, of reproductive forms, and immature individuals. It takes 9 weeks for them to develop from the egg to the adult stage and 3 to 6 years for them to produce a well-developed colony.

Carpenter ants are distributed over most of the country.

Control: Carpenter ants are controlled by applying poisonous dusts, sprays, or fumigants to their nests or the places they frequent.

Sanitation measures: Remove and destroy logs and stumps that harbor colonies. Seal crevices present in foundation walls to prevent their entry. Repair leaks in porch roofs.

Chemical applications: (1) For buildings, dust with 5 percent chlordane; 4 percent rotenone (derris powder); 10 percent DDT; or with sodium fluoride. Use about a tablespoonful per crevice. These are most effective if applied in warm, dry weather. If colonies occur in decaying wood in porches and columns, soak the wood with a 5-percent solution of pentachlorophenol (a wood preservative as well as an insecticide). (2) For tree cavities or stumps near shrubbery, stir 8 teaspoonfuls of 50 percent chlordane wettable powder into 1 gallon of water and soak the infested wood with it. Do the same with the 48-percent emulsion made from this chemical. The dusts mentioned for use in buildings can also be employed. (3) For poles and posts, introduce any one of the following materials into the cavities: A mixture composed of equal parts coal-tar creosote and gasoline; a 5-percent solution of pentachlorophenol; a mixture of either orthodichlorobenzene or trichlorobenzene and kerosene (1 to 4 parts by volume); one of the sprays made from chlordane; or fumigate with carbon tetrachloride after sealing all openings except the one being used. The latter also should be sealed as soon as the chemical is applied.