Robyn Stewart
If you have spent any duration of time in the South, I’m sure you are well familiar with the unpleasant experience of getting bitten by fire ants. Fire ant hills are prevalent in almost every county in Georgia and can be seen in yards, pastures, alongside roads, and other places. There are two different species of fire ant– the red (Solenopsis invicta Buren) and black (Solenopsis richteri Forel), both of which are invasive species in the southern United States. These species were brought from South America into Alabama in the 1930’s and have quickly spread and become a nuisance ever since.
The first step in pest management is identification. Imported fire ants are often identified by the mounds they build or their bites, but they are also known for their aggressive swarming behavior if their mound is disturbed. Most fire ant colonies consist of winged males, winged females, one or more queens, and worker ants. An average colony may contain over 500,000 workers and several hundred other winged forms and queens. Some colonies have single queens, while others have multiple queens. Areas with single queen colonies will contain 40-150 mounds per acre, while areas with multiple queen colonies there can be upwards of 200 or more mounds per acre. Most fire ant mounds will be found in sunny open areas and can reach 18-24 inches high.
Integrated Pest Management is the most effective way of using both cultural, mechanical, and chemical means to reduce and eliminate fire ant colonies in an economic and environmentally friendly way. A common method for managing fire ants in home lawns and ornamental turf is the “Two-Step Method”. This program is suitable for ornamental turf, lawns, and pasture (double check to ensure products are safe for use around livestock if pasture). It is most effective on medium to large areas and is fairly affordable. The two steps refers to a baiting step and an individual mound treatment. Once or twice a year, a bait-formulated insecticide or product should be broadcast as directed by the label- typically at 1-1.5 lbs per acre. Baits are typically composed of small food granules (like soybean) treated with an insecticide. The worker ants will forage for the bait and bring it back to the colony, where the insecticide then kills the ants as they consume it. When used properly, baits can suppress about 90% of ants. It is usually recommended that bait be broadcasted in late spring/early summer and again in the fall for the best control of fire ant populations. The second step in this method is to apply an individual mound treatment to any nuisance colonies that are present in high-traffic areas. This may be around your house, outbuildings, water sources, etc. Individually treating all mounds is not an economically viable option for medium to large sized acreage, therefore, it should be used as a supplement for the baiting step. If you have less than 20 mounds present on your property, individual mound treating is effective, but requires more labor, more monitoring, and the ants will reinvade the space more quickly than baiting first.
Fire ants will always be an issue in Georgia, but using some IPM control methods can help reduce their numbers on your property. Always follow all pesticide label guidance for safety and maximum efficacy. If you have questions on fire ant control, contact the Lincoln County Extension Office at 706-359-3233 or uge3181@uga.edu
