Ants, ants and more ants

When Frank Meek spoke to attendees at PestWorld 2008, NPMA’s annual conference held last October, just outside of Washington, D.C., he promised that he was going to give them an unusual perspective about the No. 1 pest in the United States.

"Ants, Ants and More Ants" was the provocative title of his presentation. Meek, international technical director for Atlanta-based Orkin, said, "I’ll show you that the subject of ants is not an easy one. It’s complex and big." In doing so, he talked about biodiversity, but also briefly discussed why some control efforts fail and others succeed.

Meek explained that ants belong to the largest group of social insects on our planet. He defined "social insects" as those that have specific job functions in their individual colonies.

"According to entomologists, there are approximately 13,500 different species of social insects, including bees, ants and wasps, living on our planet. Of that number, about 9,500 are ant species — and there are probably another 10,000-plus ant species that we don’t know about that are hanging out in tropical regions and other regions of the world. To demonstrate this point, we’re constantly finding new species of ants in Florida, Louisiana and Texas, and finding that controlling them can be difficult at times."

Meek cited a British entomologist who theorized that the number of insects crawling or flying about on earth at any given time is a staggering one million trillion. "He believed that one percent of that total are ants. That means that there are ten thousand trillion ants living at any given time. Since the average weight of an ant is between one and five milligrams, and if we take the ten thousand trillion ants on earth, their biomass would equal the weight of all human beings alive today."

Giving the subject a local perspective, Meek said that there are about 700 different ant species found in North America.

"Of these, only 25 are commonly found in structures, and of these, four or five are public health threats and potentially dangerous to humans. For example, in Texas, we have issues with red imported fire ants that have caused deaths in humans and animals."

DISEASE POTENTIAL. Bites and stings are possibilities that pest management professionals are well aware of, according to Meek. But there’s also potential for disease. Ants can potentially carry disease organisms, he said.

"Several years ago, our company co-funded a University of Florida study that looked for bacteria found in common insects — insects that we don’t usually consider a public health problem. There had been reports from Europe that maintained that ants carry disease and we set out to verify that. We mainly looked at food-handling establishments because we know ants love sugar and carbohydrates. And we also know that ants eat dead insects.

"The study involved injecting dead roaches with Salmonella and then allowing the Pharaoh ants and fire ants to eat them. We recovered Salmonella from seven worker red imported fire ants. And we recovered Salmonella from most of the Pharaoh ants that ate the roaches."

Meek reported the study’s conclusion was that ants could indeed be the source of food-borne illness. "They can become a health risk, more so than just from their bites and stings," he said.

"There’s also a concern about property damage caused by carpenter ants," Meek added.

Their destructiveness is well known. They damage wood and lawns and defoliate leaves. As with fire ants, they can actually undermine pavement on driveways, causing settling and cracking, which can lead to water damage. The damage they do to buildings can also make it easy for termites to enter the area because of the openings they create."

STILL NO. 1. It’s easy to understand why pest management professionals should learn as much as they can about ants and ant management, according to Meek. "Ants, according to current data, are still the No. 1 pest in our country, based on the number of calls requesting service and the number of callbacks when control is not accomplished."

Why can ant control be difficult? "In some cases our procedures may be old, having been designed and created back when roaches were considered the No. 1 pest. If we haven’t changed our techniques to accommodate the differences between ants and roaches, our ant control procedures won’t work."

Meek provided these reminders on the differences between ants and cockroaches.

Ants are social insects and therefore have specific food requirements. Roaches are much less selective.

Ants follow chemical trails. Roaches will seldom follow each other.

Ants are active 24 hours a day. Roaches are primarily active at night.

Ants are easily seen when they search for food. Roaches prefer to be hidden from view.

IDENTIFICATION IS KEY. Discussing the importance of proper identification in ant control Meek urged attendees to study identification and get it right. "If we don’t identify the right species, our ant control efforts will fail."

About 10 years ago, at a meeting of the ESA (Entomological Society of America) participants conducted an experiment involving ants belonging to 25 different species. According to Meek, the ants were placed under a microscope and a pictorial key was provided to the 20 ESA members who volunteered. Of these experts, only two were able to correctly identify all of the 25 species.

"If the experts couldn’t do it, how can pest management professionals?" he asked. "You’ve got to master that."

IPM IS A MUST. Meek posed one more question: How do you obtain control once you’ve identified the ant species?

"IPM is a must," he emphasized. "You must find the sources, fix the conditions, and make pesticide applications only as needed, not as a routine procedure. Spraying as a regular practice is not IPM and it’s not a good approach to ant management. Most sources of ants are outside, so we must know our target species and figure out just where they’re located. And we must understand that ‘carpet bombing’— by that we mean indiscriminate spraying — is not good. You must do precision applications."

Pest management professionals have to look for water sources, because ants must have water, and minimize that water source. And they’ve got to know about bridge and tunnel destruction. "If you look at every structure as an island, you must know how ants get on that island. There are only two ways — by a bridge or a tunnel, or by hitchhiking on another creature. You can’t stop the hitchhiking, but you can find those bridges and tunnels and destroy them."

THE MORE KNOWLEDGE, THE BETTER. Meek finished his presentation by noting that effective ant control techniques arise from serious study of this complex subject and he encouraged pest management professionals to devote themselves to that study.

The author is a frequent contributor to PCT magazine and can be contacted at jfox@giemedia.com.