The Texas leaf cutting ant has to be the most frustrating of all South Texas landscape pest. These hard to control ants can strip a tree or ornamental of all its leaves overnight.

Research conducted in South America revealed that a large leaf cutting ant colony harvested 13,000 pounds of leaves over a 6-year period and excavated 44 tons of soil during the mound construction process.

Hopefully, no Kleberg County colonies are this large. However, anyone familiar with the pest will tell you that even the smallest colony is a landscape problem that can grow into a major headache.

The leaf cutting ant is quite an interesting insect. Mating flights occur on clear moonless nights during April and May usually following heavy rainfall. Mated females fall to the ground and dig small nesting galleries in the soil.

Leaf cutting ants are fungus feeders and after establishing a nest the female takes a fungus wad, that she has carried in her mouth, and begins to culture it as food for her first eggs.

The first hatch of workers is quite small due to limited food intake; however these first workers bring back leaf fragments that are used to grow more fungus, thus providing more food for future broods.

Where conditions are favorable, colonies may expand to contain over 2 million ants and several queens.

Above ground colonies appear crater-shaped, 5 to 14 inches-high and 1 to 2 feet in diameter. Below ground, the nest consists of several chambers that may reach 15 to 20 feet deep. Chambers are connected by tunnels.

Each colony has a central entrance hole and numerous lateral foraging tunnels or feeder holes. Leaf cutting ant colonies are very complex structures designed to protect the ant from predators and provide an efficient air circulation system.

Large colonies can cover an area up to an acre. In heavily infested areas it is difficult to distinguish where one colony ends and another begins.

During the summer months leaf cutting ants forage almost exclusively at night. The pest have a clearly defined foraging trail and it is not unusual for ants to travel 600 feet or more to reach a suitable plant.

Foraging trails are often littered with pieces of leaf tissue that can be traced to a feeder hole.

Considerable plant damage can occur is a few hours and ants are capable of stripping small trees in a 6 to 8 hour period.

The large size and complexity of the nest combined with the fact that the ants feed on the fungus that they cultivate makes control difficult.

Treatment of foraging trails with formulations of contact insecticides combined with the drenching mounds with an approved liquid insecticide will provide some relief.

There are also gluelike products available that will provide some protection to landscape plants. Unfortunately, it is just plain difficult to obtain complete control of large, well established colonies.