You Live In Fire Ant Territory?
Fire ants currently infest over 260 million acres in Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, and Puerto Rico. They have the potential to establish in other areas where average minimum temperatures are above 10 deg;F and rainfall is greater than 10 inches a year, or in irrigated areas. Localized infestations have also been reported in Arizona and Virginia.
Research indicates that the red imported fire ant may spread significantly further north than has been predicted in the past (including as far north, perhaps, as Long Island, N.Y. in the East, Washington State in the West, and Southern Illinois in the Midwest).
You Have Fire Ant Mounds?
Fire ant mounds are not particularly visible during the first thirty days of colony development. However, as the colony grows, the fire ant mound becomes very noticeable. It initially appears as a small amount of soil that has been pushed out of the ground. But then it grows to as high as 1 1/2 feet and 2 ft in diameter for a mature colony. Imported fire ant mounds are usually built in open sunny areas, sometimes supported by a wall, post or shrub. A mature colony will contain 100,000 to 500,000 workers. As many as 20% of the workers can be outside of the colony looking for food. They may go as far as 100 feet from their nest in that search. In the summer fire ants forage at night. In the spring and fall they forage in the daylight hours.
In most home landscapes, you should not wait for a colony to get to that size. A colony can have more than one mound all connected by tunnels just below the surface of the soil. The ants will defend those tunnels as well as the mounds, so stepping on a tunnel is just as hazardous as stepping on a mound. The mound has no external openings; underground tunnels radiating from the mound allow ants to come and go in search of food. Entrances to those tunnels can be as far as 10 yards away from the mound. The mound is a series of interlocking tunnels and chambers, which may reach more than five feet below the surface. Location of ants within the mound is dependent on weather conditions, water level and other factors.
Identifying Fire Ants
Distinguishing between ant species is sometimes difficult and some species of fire ants are native to the U.S. Generally fire ants will be reddish brown to black in color. They can be 1/8” to ¼” long. Workers are most active at surface temperatures between 72 degrees F and 96 degrees F.
Fire ant colonies may include one or more queens. Single queen colonies are very territorial toward other fire ants. Newly mated queens landing in the territory of a single queen colony are attacked and killed. Colony life is different in multiple queen colonies. Workers in these colonies are less aggressive toward workers from other mounds, therefore mounds are closer together, making areas more heavily infested. In multiple queen sites, newly mated queens are often accepted into the colony instead of being killed. Multiple queen colonies may contain a few queens or up to several hundred. Control of these colonies is challenging, because as long as one queen survives the colony can continue.