Q: We would like to treat our 84 acre farm pastures for fire ant mounds. We don’t have any livestock there but we mow them regularly. Our two dogs, though, are trained on the fields. We can’t stand how the mounds look and our dogs are tired of being stung.

A: I found three products that are labeled for use on pastures. Methoprene (Extinguish) is a growth regulator. Hydramethylnon (Amdro Pro) is a slow-acting insecticide that is carried into pasture mounds by foraging ants. Spinosad (Justice) is a nerve toxin derived from a naturally-occurring bacterium.

No matter what you use, it’s going to be expensive to treat such a large area. Your best bet might be to declare an ant free zone and treat it with Extinguish or Amdro each time.

On the long-term horizon, much research is being done regarding a parasitic fly that attacks fire ants. There is also a disease that kills the ants. Both are still in the research stage but the good news is that the fly has naturalized in north Florida, so maybe it will work its way here eventually.

Cost and effectiveness of fire ant control products

Fire ants in pastures

Evaluation of Pasture Fire Ant Control