Damage caused by the Texas leaf-cutting ant, or town ant, is confined in
the United States to southeast Texas and west-central Louisiana. The ant
causes damage to a variety of green plants throughout the year and
causes serious damage to pine seedlings during the winter when other
green plants are scarce. During this period, stands of young seedlings
may be completely defoliated and the stems girdled. The ant carries bits
of needles, buds, and bark back to its nest to serve as the medium on
which it cultivates a fungus. The fungus is the ant’s only known food.
[Illustration: Texas leaf cutting ant.]
Ant colonies are characterized by numerous crescent-shaped mounds five
to fourteen inches high, and by a series of well defined foraging trails
cleared of vegetation. The mounds may be confined to a relatively small
area or extend over an acre or more. Each mound serves as the entrance
to a football-sized, hemispherical-shaped nest which the ants construct
at depths up to 20 feet below the surface. The nests are interconnected
by a series of narrow tunnels, and connected to lateral foraging tunnels
which may surface a hundred yards or more from the colony. Leaf-cutting
ants, like many other social insects, are segregated into castes. The
queen dominates the colony and is responsible for its reproduction.
Large worker ants, or soldiers, provide protection from intrusion by
other insects, while the smaller workers collect the leaves and tend the
fungus gardens.
Various chemicals such as fumigants, contact poisons, and baits have
been used to control the leaf-cutting ants with varying success. No
natural control has yet been found.