It’s been another typical East Texas spring; the ground is warming up and nature is awakening. Finally, we are blessed with timely spring storms, providing needed water for landscapes and gardens. But, regrettably, the welcoming rain storms have brought on an unwelcome eruption of new fire ant mounds in yards and garden beds.
Actually, rain storms do not produce new colonies of fire ants. The pests were there even before the rains came. During periods of cold and less precipitation, humans retreat to the comfort of their heated homes, venturing outdoors only when necessary. Fire ants are much the same. During the cold winter they hunker down in their hives and huddle around the queen to protect her. The entrance to their nests may be closed off during this time. As the temperatures warm up, the mound is opened up and scouts are sent out to forage for food. Heavy rains waterlog the hives and the ants may be displaced from their homes and they will begin constructing new hives.
Fall and spring are the times of year when fire ants are the most active. Although it is difficult to completely rid an area of fire ants, there are processes and products for controlling them. Individual mounds may be treated when they appear using a variety of products that are available at retail stores or garden centers and are ideal for treating inaccessible colonies like those nesting under sidewalks, in plant beds and at the bases of tree trunks.
Ideally, the ants should be controlled during their active periods and when they are most vulnerable using the “two-step method." This is likely to be the most cost-effective and environmentally sound approach to treating medium to large landscape areas.
Step 1: Broadcast a fire ant bait once or twice a year to reduce fire ant colonies by 80 to 90 percent.
Fire ant baits consist of pesticides on processed corn grits coated with soybean oil. Worker ants take the bait back to the colony, where it is shared with the queen, which then either dies or becomes infertile.
Step 2: Treat nuisance mounds or colonies that move into the bait-treated areas. Step 2 may not be needed.
Some mound treatment products are available as liquid drenches, injectable aerosols, dusts, or granules that are watered in to the mound. Ants are killed only if the insecticide contacts them, so proper application is essential. These treatments are most effective when ants are nesting close to the mound surface (as they do when the temperature is mild). Colonies should not be disturbed during treatment.
Always read and follow the application instructions on the label of the product(s) that you are using.
The Texas A&M AgriLife Extension Service has an excellent resource for integrated pest management control of fire ants at www.fireant.tamu.edu. Specific instructions regarding the “two-step method” can be accessed at www.fireant.tamu.edu/controlmethods/twostep.
Act now to take control of your fire ants so that the next refreshing rain storm doesn’t bring with it an outbreak of these dreaded pests.
The Smith County Master Gardener program is a volunteer organization in connection with the Texas A&M AgriLife Extension Service.