Fall is a prime time for treating for fire ants in order to reduce the numbers that will appear in the spring, say experts. That's why, since 1998, Fire Ant Awareness Week has been held the second full week of September.
Kimberly Engler, Texas Cooperative Extension program specialist in urban integrated pest management, said, "The goal is to educate people in Texas about fire ant biology and management techniques."
The awareness campaign encourages community-wide efforts, where all residents on a block apply fire ant treatment at the same time on the same day, to maximize its effectiveness.
This approach has been tried on a limited basis in two Dallas neighborhoods, she said, but documentation to support the effort or its results is not available.
This year the focus is on a more organized, documented event to see how well a community-wide effort really works in North Texas and to build a proof-of-performance model for other communities to follow, Engler said.
Studies in San Antonio showed the approach reduced fire ant mounds by 94 percent and reduced the cost of pesticides by 84 percent.
A statewide study determined community-wide efforts throughout the state could reduce the impact of fire ants by $234 million. Currently, fire ants cause about $1.2 billion each year for landscape treatment and medical costs. The cost savings alone for insecticides would be $313 million.
Communities should fight fire ants with the Texas Two Step Method, Engler said. Step One is to broadcast a fire ant bait twice per year, in the fall and spring, when the yard has at least five fire ant mounds per quarter-acre, and to broadcast around 1 to 1-½ pounds per acre. That will place only a low level of insecticide in the environment.
Step Two is to re-treat individual mounds in high traffic areas, such as along driveways and around mailboxes.
Fire ant bait is made of defatted corn grit coated with soybean oil, which is attractive to fire ants. The insecticide is dissolved in the soybean oil. Worker ants collect the bait and take it back to their colony to share with other ants, including the queen. Some baits cause the queen to die while others make her unable to produce fertile eggs. Both methods ultimately cause the colony to die.
Bait methods of fire ant control take longer than individual mound treatments, Engler said, but their effectiveness can reach a 90 percent suppression rate for six to 18 months.
"The bait should get rid of the fire ant population in your yard, but it usually takes longer, on average, two weeks," Engler said. "The range on the various bait options on the market is anywhere from two days to four weeks. Treating in September also means fewer fire ants next year."
Community-wide treatment efforts are also considered an integrated pest management approach because the bait product contains less than 1 percent insecticide and solely targets fire ants, she said. This is a more environmentally friendly and safer alternative treatment than traditional methods, she added.
For more information go to fireant.tamu.edu. The Web site contains pictures and information on fire ant research conducted since 1996. To organize a community-wide treatment effort in the Dallas area, call Engler at (972) 952-9221 or e-mail her atk-engler@tamu.edu.