Under Fire: Fire Ant Management for Pastures and Hayfields

Adapted from Fire Ant Management in Pastures by S. Barbara, NCSU Extension Entomologist

By Lynn Stillwell Sampson County Livestock Agent Swine and Waste Management

Fire ants are a major problem in NC and other southern states. We’ve all seen there mounds or worse not seen them and been stung. Fire ants are found through out southeast NC and are quickly spreading westward. Sampson and Duplin Counties along with 49 other

counties are under quarantine and movement of hay outside of the “red counties” is regulated by the NC Department of Agriculture and Consumer Services and requires a permit.

Fire ants prefer open land and sunlight, which they readily obtain in our pastures and hayfields. The presence of fire ants can have major impacts on livestock operations through animal injury, equipment damage, lower yields in hay production, reduced feeding and many other ways. Unfortunately there is not easy solution to managing fire ants in your hayfield, it really all depends on the number of mounds and their locations. Very few of the many fire ant pesticides are labeled for use in pastures and hayfields. There are no effective sprays for control of fire ants in pastures. There are some chemicals for treating mounds, and some baits that contain insect growth regulators (IGRs) that may be used in pastures. For a complete list of baits and mound drenches available consult the Ag Chemical Manual or contact you County Extension Agent.

Direct mound drenches have advantages and disadvantages to balance.	Broadcast bait treatments also have advantages and disadvantages.
Advantages- Fast acting Insecticides applied only to targeted mounds	Advantages- Quick and easy application Less hazardous, generally Least expensive method for large areas Less labor required
Disadvantages- More expensive for large areas More labor intensive Treatments affect only older colonies showing visible mounds	Disadvantages- Slower than liquids (too slow for situations where stings are a major concern) May harm some helpful non-target ants

The best time of year to treat for fire ants in mid-spring and fall, or in the morning when air temperatures are around 70 degrees F. Do not apply baits and drenches at the same time as ants will not forage and accept the bait while disrupted by the poison from a mound drench. To determine if a mound is active place a few potato chips or some other snack, if ants are noticed within 30 minutes then the colonies are active. For more information on fire ants and control contact your county Extension office.