Texas Leafcutting Ant (Atta texana)

Anonymous. 1989. Insects and Diseases of Trees in the South. USDA Forest Service. Protrotection Report R8-PR16. 98 pp.

Taxonomy

Domain	Eukarya
Kingdom	Animalia
Phylum	Arthropoda
Subphylum	Hexapoda
Class	Insecta
Subclass	Pterygota
Infraclass	Neoptera
Superorder	Holometabola
Order	Hymenoptera
Suborder	Apocrita
Infraorder	Aculeata
Superfamily	Vespoidea
Family	Formicidae
Subfamily	Myrmicinae
Tribe	Attini
Genus	Atta

Scientific Name

Atta texana

Scientific Name Synonyms

Myrmica texana

Oecodoma texana

Common Name

Texas leaf-cutter ant

Importance

The Texas leafcutting ant, or town ant, is a serious pest of pine regeneration in the upland areas of west central Louisiana and east Texas. It does not occur in other forested areas across the South.

Identifying the Insect

Leafcutting ants are rust colored with large heads. They live in large colonies. The queen is 3/4 inch (18 mm) long, and lives in an underground chamber. The worker ants are most numerous and range in size from 1/10 to 1/2 inches (3 to 12 mm) long. Ant nests consist of numerous crescent-shaped mounds on the surface and extensive underground passageways and chambers. The mounds may be restricted to a small area or extend over an acre or more. Foraging trails cleared of vegetation are often present around the central town area.

Identifying the injury

Leafcutting ants will attack hundreds of plant species. They damage all species of southern yellow pine by removing the needles, buds, and bark of seedlings during the winter and early spring when other green vegetation is unavailable. This is when large acreages of pine regeneration can be killed around leafcutting ant colonies. Once the seedlings have reached the height of 2 to 3 feet, they are rarely killed by leafcutting ants.

Biology

The ants have a mating flight in May or June. After mating, the females establish nests beneath the soil and become the queens of the colonies. Worker ants carry the cut foliage and other vegetative material back to the nest, where it is used to culture the fungus that is their primary food.

Control

There are few natural enemies. Control can be attained by fumigating the nest.