No walk in the park: fire ants march through park land, wreaking havoc on children and pets.

As spring approaches most people are anxious to beat their cabin fever and get outside to enjoy the weather. It's often a time to recreate and relax outside. But for those living in the southern United States, spring also means the emergence of the Red Imported Fire Ant (RIFA), one of the most resilient pests in the country.

In the spring of 2004, Dan Wells, Irmo Chapin Recreation Commission executive director, had just these pests on his mind as the weather warmed. As the director of three large parks in Columbia, S.C., Wells knows one of his most challenging responsibilities is keeping his parks safe for all visitors, and that means keeping fire ant populations under control.

An Expensive Pest

For a majority of the population, mention fire ants and images of small, red insects are conjured. But for the nearly 40 million Americans living in fire antinfested states, these seemingly harmless insects have the ability to stir fear into their hearts--and not without reason. These invasive species, which were introduced to the U.S. in the 1930s through a port in Mobile, Ala., have since migrated to infest 13 southern states (known as the "Fire Ant 13"), and continue to move north and west. Americans have spent an amazing $2 billion annually in the fight against fire ants. These expenses are incurred not only through pesticide use, but also as a result of structural damage, loss of live stock and healthcare costs.

Unfortunately, the most susceptible to fire ant bites are those who don't know any better than to step on a mound--often times children and pets.

"Each year, fire ants sting millions of people, inflicting pain, causing itching and burning, and potentially leaving behind scars," says Tim Davis, Clemson University researcher and area-wide fire ant specialist. "A full-blown colony of fire ants can number up to 500,000 members and when disturbed, hundreds, sometimes thousands of ants will attack an intruder."

Additionally, studies show that 10 to 15 percent of those stung by fire ants experience severe localized allergic reactions, 1 to 2 percent of the population can experience systemic reactions that, in rare cases, result in death.

A Park Under Attack

Luckily, Wells is familiar with these pests and has ensured that his grounds maintenance crew knows how to detect and treat fire ant infestations. Similar to common nuisance ant species, such as pavement or argentine ants, fire ants are small and reddish-brown in color. In fact, they are so similar that most cannot be differentiated without the use of a magnifying glass.

However, fire ants provide one telltale sign that they are unlike other, harmless ants--their mounds. Unlike other ant mounds, with one central opening, fire ant mounds resemble worked soil, and have no single entrance. If located in a frequently mowed area, the mounds will remain very low to the ground. However, if located in a less manicured location, mounds can reach up to three feet in height.

"With so many guests visiting our parks each year, we just can't take chances with fire ants," says Wells. "Each year, our parks are host to a number of scout troops, day camps, festivals, picnics and school trips, and we need to ensure the safety of each and every guest."

Wells knows that fire ant control is a long-term commitment due to the insect's reproductive potential and that choosing the method that best fits the needs of his environment is key.

In the past, Wells and his maintenance crew practiced the "Two Step Method," which included broadcasting a fire ant bait while ants forage, and then about a week later retreating problematic mounds with an individual mound treatment. However, when dealing with hundreds of acres, this process could be grueling.

Now, however, companies are taking fire ant prevention seriously, and have begun to research ways in which to treat large areas. Rather than using individual baits, maintenance crews can use a granular formulation of the chemical that kills fire ants for up to one year with just one application. As opposed to baits, a broadcast granular is spread over turf like fertilizer. The main advantage for Wells and his crew was that the granular lasts longer than baits, cutting their fire ant maintenance time dramatically. "We were excited to gain a new level of fire ant control," says Wells. "It also allowed us to spend our maintenance time more effectively."

The Columbia parks crew spread broadcast granular fire ant control once a year. To provide immediate protection, baits are used on grounds that will be utilized by the public within a short time period. Although broadcast granular products are more expensive up front, baits can be more expensive through the course of a season due to their weak residual.

Granular products may cost more than $200 per acre per year but provide 98 percent control. In comparison, most commercial fire ant baits cost $20-30 per acre, but require multiple applications and normally provide only temporary control.

The Ants Continue to March

Fire ant technology has come a long way in the past few decades thanks to the growing number of research dollars devoted to studying their biology and behavior. Despite technological advances, fire ants have proven to be a tough competitor, even for the entomologists who are most familiar with their daily routine. With no natural predators in this country, fire ants are one of the most resilient species in the world, able to survive, and actually flourish in natural disaster conditions.

In the case of a flood or hurricane, as water rises, fire ants form a "survival ball," with the queen safely protected inside, and will float until they hit dry ground, sometimes miles away. While in this survival mode, fire ants inject two to three times as much venom in their victims than at other times.

In a joint study by the USDA's Agricultural Research Service Center and the University of Arkansas, researchers found that the ants are making their way north and west into areas of the United States previously thought to be too cool for fire ant activity. A separate report published in the Journal of Allergy and Clinical Immunology (JACI) in 2000 indicates that fire ants are traveling north and west at a rate of about 120 miles per year.

"This migration is an indication that fire ants are more cold-tolerant than scientists previously thought;' explains Dr. Nate Royalty, entomologist with Bayer Environmental Science. This means that the "Fire Ant 13" may soon be joined by other states. Already, parts of Arizona, Kansas, Kentucky, Mary land, Missouri and Virginia are seeing fire ant activity.

For outdoor enthusiasts, awareness is the key to prevention. Although park and recreation maintenance crews are making strides in fire ant management, it's more than likely these pests will be with us for years to come. Instead of letting these pests ruin a day in the park, it's important know how to deal with them. Fire ant experts throughout the South offer the following tips:

* Survey the area--visually inspect your surroundings to determine the presence or magnitude of an infestation 

* Test for foraging--fire ants are most effectively treated while they are foraging. To test, carefully place a potato chip (an ideal bait for fire ants) on or near a mound. Fire ants are foraging if they appear and begin to eat the chip within 30 minutes.

* Protect children--pay particular attention to areas where kids play, especially around the bases of playground equipment and sidewalks. More children are stung each year by fire ants than all other insects combined.

* Safeguard pets--kenneled or confined pests are defenseless against fire ant stings. Before placing pet food on the ground, be sure it is clear of any mounds, as fire ants will quickly swarm any food source in their vicinity.

* Seek professional advice--fire ant mounds can reach as far as two feet below the surface of the ground, and as far as eight feet in width. Attempting to control them alone can be expensive and frustrating. Professionals are trained in the latest fire ant technology and techniques.

Interesting facts about fire ants

* Fire ants arrived to the United States in the 1930s in soil used for ballast of a ship

* There are currently more fire ants in this country than in their native South America

* Fire ants have no natural predators in this country

* A fire ant colony can have as many as 500,000 members and multiple queens

* Currently 325 million acres across the U.S. are infested with fire ants