SAN ANTONIO About 250 entomologists and biologists gathered here last week to discuss solutions to the red imported fire ant problem that has spread across the southern United States. Everything from population dynamics to queen assassinations to parasites was discussed, but experts agreed there was still no one solution.
“The purpose of this conference was to bring together all the researchers who are doing work on fire ant biology and control and bring them together with people in industry and people doing applied research in insecticide control,” said Nathan Riggs of San Antonio, county extension agent-integrated pest management.
“All of this two-way exchange benefits not only the universities but the general public as well,” Riggs said.
Still, as Riggs noted, there’s probably not one solution to the problem.
“I wish we had one,” he said. “We have to utilize all of the different options available – whether insecticides, biological, non-chemical, and maybe changes in behavior of people who have to deal with the fire ants. There’s no silver bullet yet, no Lone Ranger on a white horse.”
Imported fire ants pose a major problem in Texas, explained Dr. Curtis Lard, who is with the department of agricultural economics at Texas A&M University.
According to a study completed in 1998, fire ants cost more than $750 million in urban areas. This includes household, golf course, school and electrical utility costs to treat and repair damage caused by fire ants in San Antonio, Houston, Dallas-Fort Worth and Austin, Lard explained.
A 1999 study of fire ant damage to the state’s agricultural industry revealed fire ants cost farmers and ranchers an additional $90 million in damage and treatment, Lard told the group.
Riggs said, “You can’t eradicate the little monsters. Fire ant biology does not lend itself to eradication like other insects. Their reproductive cycle is slow – the fertile females are only out at certain times of the year.”
It’s hard to predict when they will be out, a sterile male release program would not be as effective as the program that helped control the screwworm in Texas in the 1950s, Riggs ezplained.
Complete pesticide eradication is very expensive environmentally and financially.
“Biologically it’s just not an option,” Riggs said.
The Texas Agricultural Extension Service promotes managing imported fire ants in areas larger than individual properties, such as entire city blocks or neighborhood associations, said Dr. Bart Drees, coordinator of the Texas Fire Ant Project.
Community-wide programs like those taking place in San Antonio and Austin are showing the success of this approach. In these programs, residents are encouraged to use the Two Step method where baits are broadcast to kill most of the fire ants and individual mound treatments are only used to eliminate unwanted nuisance mounds. This is the best method for use in large areas with high numbers of fire ant mounds, Drees said.
Riggs added, “The benefits that come out of urban programs such as this are reduced pesticide use, reduced cost (to the homeowners) and a reduction of fire ants in people’s lawns.
“If people can’t enjoy their lawns, being outside with their children, what’s the use of being outside?”
In some instances, residents who were spending $40 to $50 per year per homeowner to treat the problem are now spending perhaps $5 twice a year on pesticides to participate in the neighborhood program, Riggs said.
Additionally, in a Mount Pleasant public housing project, residents reduced their pesticide cost from $12 a year to $2 to $7 per year by using the Two Step method, he added.
“That doesn’t sound like a whole lot, but if you’re on a fixed income, an extremely low income, $12 is extremely taxing on your finances,” he said.
Smaller amounts of pesticides are being used by using the Two Step method.
Native ant populations also have increased in some of these neighborhoods, Riggs said.
“A lot of folks don’t realize a lot of our native ant species are probably the best barrier we have against fire ants, a natural barrier.
“By examining lawns and noting the number of fire ant mounds we have, even if it’s just a few, we can treat the mounds and let these native ant species flourish and gain strength. The stronger the native ant species are and the more species we have, the fewer fire ants you’re going to have in your lawn in the long run,” Riggs said.
Further information on identifying native ant species is available from http://fireant.tamu.edu
-30-