**Texas Leafcutting Ants** (*Atta texana*) are a highly social, specialized ant species native to the southern U.S. The conflict is severe, localized **agricultural and landscape destruction**: they are one of the 40 known species of “fungus-farming” ants. They cut and carry massive amounts of **fresh leaf, flower, and needle material** back to their nest, not to eat it, but to use it as a substrate to grow a specific fungus (their only food source). This defoliation can quickly strip small trees and shrubs and causes major damage to timber, citrus, and garden plants.
Taxonomy and Classification
Texas Leafcutting Ants belong to the order Hymenoptera, family Formicidae. They undergo complete metamorphosis. They form massive, deep, perennial colonies that are extremely difficult to eradicate, some covering over 2,000 square feet.
Physical Description
Adult Workers are variable, 1/16 to 1/2 inch long.
- **Appearance (Key ID):** Reddish-brown ants with sharp, prominent **spines** on the thorax and large heads. They exhibit a size caste system, with major workers having massive heads.
- **Behavior (Key ID):** They form continuous, moving **parades** of ants carrying small, semi-circular pieces of leaf material overhead along clear, established trails, marching toward the nest entrance (the characteristic “moving foliage”).
- **Nest (Key ID):** Large mounds of loose, excavated soil with many crater-like openings (often 6 to 12 inches wide) where the workers enter and exit.
- **Conflict:** Severe defoliation and widespread landscape destruction.
Distribution and Habitat
Texas Leafcutting Ants are found in Texas, Louisiana, and parts of the Deep South U.S. Their habitat is open, well-drained soil, often in pastures, forest edges, or fields.
Behavior and Conflict
The conflict is high economic damage and extreme resilience.
- **Fungus Dependency:** Because they feed only on their cultivated fungus, standard sugar or protein ant baits are useless. They require specialized baits that contain a fungicide or growth regulator that kills the fungus garden itself.
- **Deep Nests:** The colony can extend 15 to 20 feet deep, making physical or liquid chemical treatment of the entire structure impossible.
- **Defoliation:** They can strip a mature citrus tree in a single night.
Management and Prevention
Control requires specialized, persistent baiting and colony targeting.
- Use baits specifically formulated for leafcutting ants (often containing hydramethylnon or sulfluramid), which workers carry into the nest, contaminating and killing the fungus garden.
- **Protection:** Use metal or slick plastic barriers around vulnerable young trees and plants to physically block access to the foliage.
- For massive colonies, professional pest control may be required to inject specialized dusts or granules into the nest openings.
Conservation and Research
Texas Leafcutting Ants are managed as high-priority agricultural and forest pests. They are also highly conserved for their complex, mutualistic relationship with their fungus and their importance in the study of social behavior and agriculture.