Leafcutter Ant

The Texas leafcutter ant, Atta texana (Family: Formicidae, Subfamily: Myrmicinae), is a highly dimorphic species with distinct worker castes. Minor workers are small (2-3 mm) and tend fungi, while major workers, or soldiers, are much larger (up to 12-14 mm) with massive heads and powerful mandibles, specialized for cutting leaves and defense. Their coloration ranges from reddish-brown to blackish-brown. Queens are considerably larger (up to 20 mm), alate during nuptial flights, and have a unique physiological adaptation to carry a starter pellet of fungus from her natal colony. Males are also alate. This species exhibits complete metamorphosis. Colonies are founded by a single queen and can become massive, housing millions of individuals within a complex network of subterranean chambers over many years, with some colonies estimated to be decades old.

Atta texana exhibits an extraordinary mutualistic relationship with a specific fungus, which it cultivates as its sole food source. Workers meticulously cut and collect fresh plant material (leaves, flowers, grasses), which they transport along well-defined foraging trails back to the nest. This plant material serves as a substrate for their symbiotic fungus, which they 'feed' and maintain within subterranean gardens. Foraging activity is primarily crepuscular and nocturnal but can extend into daylight hours, especially on overcast or humid days. They are highly destructive to vegetation, defoliating plants and trees in their foraging range. Soldiers fiercely defend colonies, and their powerful mandibles can inflict a painful bite.