Red imported fire ants are 1/8-1/4” long and reddish-brown or black.
With hay moving around the country due to this year’s drought, officials in several states are concerned that the red imported fire ant (RIFA) could unwittingly be, as the pesky insect’s name states, imported into new areas.
Late last month, soon after a south-central Missouri farmer discovered RIFA while unloading hay bought from Florida, University of Missouri Extension warned about the pest. The insects in the farmer’s hay went on the attack after being disturbed rather than scattering as other ants typically do.
“I don’t think this is necessarily an isolated incident,” says Stacy Hambelton, an Ozark County Extension ag business specialist. “Because of the drought, we have truckload after truckload after truckload of hay moving into and through this area. A lot of it is coming from places where they have problems with this kind of fire ant.”
Significant populations of RIFA, an aggressive, stinging insect native to South America, are found in 13 Southern states (see quarantine map), covering 320 million acres, according to USDA’s Animal and Plant Health Inspection Service (APHIS). Of major concern: The ants can infect new areas by hitching rides in hay bales, nursery stock and other products that contain, or have been in contact with, soil. To keep that from happening, USDA has required that hay in areas with established RIFA populations be inspected and certified before being shipped from a quarantine zone.
The ants are 1/8-1/4” long and reddish-brown or black, according to the Oklahoma Department of Agriculture: “They are best recognized by their aggressive behavior and mound-shaped nests. They respond quickly and aggressively when disturbed. The ants normally eat insects but will feed on almost any type of plant or animal material, causing direct danger to crops.”
While RIFA attacks are rarely fatal to people or livestock, the ants still pose serious economic and ecological threats, says Missouri state entomologist Richard Houseman. “They can damage soybeans and other crops, and their mounds may disrupt farm operations and damage equipment. Red imported fire ants disrupt natural ecosystems by displacing beneficial native insects and killing small mammals, reptiles and ground-nesting birds.”
Buying hay from Northern states might be the best bet for heading off problems, Hambelton says. But that might not be feasible in light of this year’s drought. “I’m not sure there’s enough hay available to the north and west of here to take care of all the need we have for hay.”
Buyers who must buy in areas covered by the APHIS quarantine should ask for proof that the hay has been certified RIFA-free by either USDA or a regulatory official in the state from where the hay originated.
To make sure ants aren’t hiding in the hay, Hambelton recommends placing a piece of hot dog, a dab of peanut butter or a card soaked in peanut oil on each bale. “Leave it on the hay for an hour or so, then come back to see if any ants have been drawn out. The cost of a few hot dogs or a jar of peanut butter isn’t really all that much if it gives you some peace of mind. If you do find fire ants in the hay, contact your local Extension office, state entomologist or state ag department for advice on how to get rid of them.”
Sellers caught moving imported fire ants out of quarantine areas can be fined. “At the very least, you’ll be required to transport the hay back to its place of origin at your own expense,” notes Kenny Naylor, environmental resources specialist with the Oklahoma ag department. “So it pays to be diligent about making sure that you’re not moving these ants around.”
For more information, download a two-page advisory from APHIS.