Leaf cutting ants are social insects. Queen ants deposit eggs that hatch into cream colored larvae. In the spring, some larvae develop into larger (3/4-inch long) winged male and female ants, called reproductives.
Males have much smaller heads than do females and both have long, smoky black wings.
Sometime between April and June, on clear moonless nights and usually after heavy rains, these winged ants leave the colony on mating flights. These ants are attracted to porch lights and are some of the largest ants encountered in Texas.
Virgin queens carry a small piece of the fungus from their parent colony in a small cavity inside their mouths. After mating, the males die. The queen loses her wings and digs a small tunnel or gallery in which they begin laying eggs and culturing her fungus garden on her feces.
The queen feeds largely on her own eggs until small worker ants develop from the surviving eggs and begin to collect foliage on which to culture the fungus.
Colonies can survive for many years and colonies may contain over two million ants. The nest interior may be 15 to 20 feet deep and contain numerous chambers interconnected by tunnels.
Worker ants remove leaves and buds from weeds, small grains, forage and turf grasses, fruit and nut trees including plum and peach trees, blackberry bushes, and many ornamental plants. Defoliation is particularly noticeable during winter months.
Worker ants forage when temperatures range from 45 to 80 degrees during the year, but mainly at night during the summer.
Worker ants travel up to 600 feet or more along foraging trails and dismantle foliage into leaf pieces that they carry back to the colony over their bodies. In the colony, the pieces of leaves are used to raise a fungus. All members of the colony feed exclusively on the fungus.
The Texas Forest Service listed a number of procedures for the Ant Block (the only registered product to treat the leaf cutting ant) to increase likelihood of cut ant control as follows:
1) Apply bait when ants are active which would be late afternoon in summer and mid-day in winter. Dr. Roy Parker, our extension entomologist, thinks the winter treatments would be best since there are fewer resources available for the ants.
2) Avoid applying to wet soil or when rain is expected in within 24 hours.
3) Avoid prolonged exposure of bait to direct sunlight.
4) Do not apply during prolonged cold weather below 50 degrees.
5) Use only fresh bait, store in a cool dry place, keep container tightly closed, and use the bait within three months.
6) Apply 0.75 lb per colony [many openings make up one colony].
7) For single-mound nests or widely scattered holes, apply one ounce or about one capful per individual mound.
8) Do not apply more than 2.0 lb./acre.
9) After broadcast over the central nest area, apply about 1.0 ounce per foraging trail, and apply 1/3 ounce to each satellite mound with heavy ant activity.
9) Check the treated areas after 30-40 days to see if repeat treatment is necessary.