Most think of fire ants as a minor pest that you find in your yard as you walk to the mailbox, but those in the agricultural field know, they are much more than that. Fire ants, specifically red imported fire ants, are an invasive species that was accidentally introduced in the early 1900s from South America. As with other invasive species, these fire ants spread quickly and became a problem throughout the southeast. Colonies can contain up to 300,000 individual workers once they are established for a few years. These colonies can create massive mounds that can cause damage to equipment and cause bare spots resulting in less forage available for livestock. Red imported fire ants have been observed to have anywhere between 50 to 200 mounds per acre, which can disrupt daily operations. Although cases of fire ants killing livestock are extremely rare, weak and vulnerable animals can be fatally injured due to fire ant bites.
Managing these pests using granular baits is the most effective method. Bait can either be broadcast over an entire area or applied directly to each mound. Application rates can vary by product, but tend to be around 1 pound per acre and the cost can range from $10-15 per acre. Single applications can last up to a year and reduce the number of mounds by 80% the following year in some instances. These products disrupt the growth process of the immature ants and the colony eventually runs out of future workers. Late spring and early fall are the best times to apply bait when the ants are most active. Placing a potato chip near the mound for 5 minutes or so is a great way to gauge the level of foraging activity. If there are ants on the chip after a few minutes, then it is a good time to apply bait.
With the low application rates of these products, using a specifically designed spreader to accurately apply granular bait is a great strategy. Both Orange County Cooperative Extension and the Soil & Water Conservation District have fire ant bait spreaders available for farms to rent. If you need assistance with managing fire ants in your pasture or hayfield, please contact the Cooperative Extension office at (919) 245-2050.
