You need the right tools and knowledge
Nearly everyone who cares for a lawn, golf course, park, sod farm or any other type of turfed area in the South is a veteran in the war against red imported fire ants. They have persisted despite tremendous amounts of research and massive suppression efforts, which leaves those on the front lines constantly searching for new tools and techniques to control fire ants.
“Anywhere we go, we can usually fill up a room pretty quickly,” says Tim Davis, fire ant specialist with the Clemson University Cooperative Extension Service in South Carolina. He is one of many extension professionals throughout the South providing training sessions for those who want an upper hand in this battle.
Davis has conducted scores of trainings in many different states, and he typically begins his programs by discussing the biology of fire ants and what makes them so difficult to control. Primarily, it’s because they can re-infest from long distances and can reproduce quickly, he explains.
|Courtesy of Tim Davis/Clemson University.|
|A four-wheeler with an attached seeder is used to cover large areas with fire ant bait. At top of page, The imported red fire ant poses a threat to turfgrass—and people—throughout the Southeastern U.S.|
“There’s no such thing as eradication—that’s not going to happen,” says Davis. However, by using the right tools and techniques, it is possible to effectively suppress fire ant populations. That’s why he is frustrated when he hears from people who say that control is impossible; others who pass along misinformation or myths about fire ants; or about claims of secret home remedies (“anything they have under the kitchen sink”) purported to work. Other common techniques he hears about include “blowing up” or “burning up” the ants.
“Of course, the people that come to me are interested in doing things correctly,” says Davis, “but I hear all the time from people who say, ‘I’ve tried this chemical or that chemical and they don’t work.’ Well, I’ve done hundred of field trials, and I know that the chemicals I’m discussing do work. The key is that you have to know how to use them.”
As with nearly any pest, control is not as simple as buying a chemical and putting it out, he emphasizes. Davis says that in his training sessions: “We talk about all the different chemicals that are available and methods for their use. We talk about strategies for applying the chemicals in a way that’s going to give you the best level of control. It’s not as simple as taking a product off the shelf and putting it out there.”
People are sometimes surprised by the complexity of controlling fire ants, he adds. For this reason, he often recommends to homeowners that they hire a professional. “When you hire a professional, you’re not necessarily getting access to control products that you couldn’t get as a homeowner—what you’re getting is their knowledge,” Davis explains. “They have the understanding and the equipment to apply the products properly. So the homeowner doesn’t have to learn everything themselves.”
He compares the situation to a home builder, who has all the right tools and knows how to use them in the right way in order to build a house. “I can cut a board with a hammer, but it’s not pretty and it’s not the right tool for the job,” Davis explains. “Professionals with the proper training will have all the right tools to control fire ants, and know how to use them the right way—and in a way that’s safe for the environment.”
Davis says that the key to suppressing fire ants is to use the proper tool in the proper manner. Fortunately, thanks to the extensive training efforts made over the years, “Most lawn care professionals are using the right chemicals,” says Davis. “They know that if they’re using baits, they have to get them out when the ants are foraging—and they know how to determine that. They know the differences between the various baits, and know how to choose properly.”
One of the training programs that Davis takes part in is a certification session offered by Bayer for those interested in using the company’s TopChoice control product. (Bayer has a Web site, www.nofireants.com, which includes a list of professionals who have completed that training.)
|Here, researchers collect fire ants for testing purposes. “This process demonstrates the ants’ ability to attack anything that hits the mound,” adds Tim Davis, fire ant specialist with the Clemson University Cooperative Extension Service.|
Though not intended to be a substitute for participating in a fire ant training program, Clemson Extension offers a bulletin (www.clemson.edu/sandhill/userfiles/file1446.pdf) with basic guidance in the three primary approaches to controlling these ants:
• individual mound treatments (IMT), which are effective at killing ants only in the mounds that are treated and which are often used when there are only a few, pronounced mounds present;
• broadcast baits, which can provide 85 to 95 percent control when applied while ants are actively foraging; and
• broadcast granular products, which offer similar rates of control, but can be expensive and control only those ants in the area treated.
“Combining each of these strategies can be very effective in an overall management plan,” the Clemson advisory explains. “For example, the two-step method uses a broadcast bait treatment then uses the IMT to control the most visible or problematic mounds. Another option is to use the broadcast granular products in most of the yard, then treat difficult to reach areas and edges with a bait. In large areas, a site analysis will reveal that in some areas it is more important to control ants than in others, such as the place were the kids play. In such a scenario, you can use the broadcast granulars in the ‘zero tolerance’ zones and use the baits where killing 90 percent of the population is good enough. This allows the use of the premium products to reduce the contact with fire ants without spending the money to do a full treatment.” As with all control products, be sure to follow label instructions.
|Courtesy of Sherri DeFauw/USDA.|
|Imported fire ant mounds are easy to locate visually. “However, the contrast between ant-affected turf and undisturbed turfgrass is not so noticeable,” explains Sherri L. DeFauw, USDA research agronomist. “Despite the absence of observable differences, a spectroradiometric device [which is capable of seeing small differences in reflected light] can detect the difference between these two turf targets.”|
Biological controls are also part of the overall strategy to control fire ant populations, but most are currently being used only by government agencies and researchers, and aren’t available commercially. “We have two species of ‘decapitating flies’ that we have released in all the fire ant-infested states at various locations, and we’re allowing them to establish and spread naturally. We’re still working on other species,” says Davis. “We have another biological control, thelohania, that occurs naturally. Right now, the only way we can get it to spread is to take infected larvae from one colony and move it to another colony—we don’t have any way to spray it.”
Work continues on other biological controls, but none promises to provide 100 percent control. “They still have fire ants in South America, where all of these biological controls are coming from,” says Davis. “So, there’s no silver bullet on the horizon.”
The focus of most fire ant control efforts at the moment is on education. “Right now, we’re not seeing a lot of new chemistry or new control techniques being used,” says Davis. “That’s partly because the tools we do have are very effective—when people understand how to use them.”
There are many people throughout the Southeast involved in the effort to train people in the proper control of fire ants, says Davis. He recommends contacting your state or regional extension professional for further guidance and information about local fire ant training opportunities. There also are a number of comprehensive Web sites offering fire ant information:
• Texas Imported Fire Ant Research and Management Project: http://www.fireant.tamu.edu
• USDA Agricultural Research Service’s Areawide Fire Ant Suppression program: http://www.fireant.ifas.ufl.edu
• Alabama Fire Ant Management Program: www.ag.auburn.edu/enpl//FireAnts/
New research is being conducted to further understand and track the movement of fire ants. Two especially interesting projects are taking place at the University of California Riverside and through the USDA’s Agricultural research service.
At UC Riverside, Entomologists Michael Rust and Les Greenberg recently completed a three-year project designed to learn how ants spread during mating flights and the weather conditions that prompt swarms of the insect.
“Normally, in the southeastern United States, fire ant flights are triggered by warm weather, rainfall and subsequent high humidity,” explains Rust. “Under California conditions, we have seen flight activity associated with irrigation.”
“Rain is a precursor to fire ant flights. However, the queens wait for sun and blue sky before they’ll fly,” says Greenberg. “Also, they don’t fly if it’s windy. So, it’s unlikely that fire ants will fly during or shortly after thunderstorms.”
Having tested and perfected a device to study flight in fire ants, the researchers took their equipment to Alabama in 2007 for field trials with Urban Entomologist Art Appel and Extension Entomologist Fudd Graham from Auburn University. The scientists used a 10-foot helium balloon packed with weather instruments to record temperature, humidity and wind speed. They used a ground weather station to compare with the instruments on a tether. Large sticky traps were lifted with the balloon at 50-foot intervals along the tether. These triangular traps are about 2 feet long, and their inner surfaces are coated with a sticky material that traps the insects.
With the balloon and weather equipment, Rust and Greenberg logged wind speed, temperature, humidity and barometric pressure at the swarm, as well as conditions measured at various altitudes. “These discoveries will help regulatory agencies to search for new infestations in particular areas based on weather conditions and the influence it has on fire ant swarming, rather than randomly searching for new infestations,” says Rust. “The ability to trap flying ants could also lead to the development of attractants that could be put into traps as a monitoring tool.”
Meanwhile, at the USDA’s National Biological Control Laboratory in Stonesville, Miss., Research Agronomist Sherri L. DeFauw is using advanced technologies to help detect fire ant mounds in turfgrass settings.
She recently completed research using “hyperspectral remote sensing” equipment to “examine seasonally-acquired broadband spectral reflectance patterns for ant-affected versus undisturbed turfgrass and soils” and to “identify wavebands that enhanced the detection of imported fire ant mound features.”
In laymen’s terms, DeFauw’s work showed how fire ant infestations can be recognized in turfgrass settings using reflected light to determine the unique “spectral signature” of ant infestations. “We identified several wavebands that showed a significance between the ant-disturbed soil and turf and undisturbed soil and turf,” she explains. The wavebands that proved effective vary by season and weather (moisture conditions).
DeFauw worked on two sod farms and one golf course, all growing Tifway 419. “I collected tens of thousands of spectra using a ground-based hyperspectral unit,” she explains. While DeFauw conducted her research using a 48-pound backpack unit, “We’re hoping to get a company interested in developing a prototype device that can be mounted on a mower,” DeFauw explains. “After all, it is the equipment that is most commonly out on the turfgrass—sometimes as often as three or four times per week.”
Aerial imagery is another possible solution; however, there are concerns that the turn-around times would mean that turfgrass managers wouldn’t be able to get information in a timely enough manner to prove useful.
In the process of the research at one site, the tests showed that ants were just beginning to move into the site. “We’re several steps away from having a device developed,” says DeFauw, “but not surprisingly, the turf managers at our test sites were very interested in the technology.” A tool that could give turf managers early notice of fire ant infestations; help them to identify and monitor their location and activity; and provide assistance in estimating population levels would be one more helpful tool in the war against fire ants.
Patrick White is a freelance writer and editor who is always on the lookout for interesting and unusual stories.