U.S. Probably Began Global Fire Ant Spread

U.S. Probably Began Global Fire Ant Spread

By Susan Milius, Science News

Genetic evidence now spotlights the United States as the source of recent fire ant invasions in the rest of the world.

The aggressive, stinging fire ants (Solenopsis invicta) aren’t native to the United States but rather to a broad swath of South America. Yet the southern United States, invaded by fire ants in the 1930s, has sent off at least eight separate waves of fire ant invasions to other countries in recent years, says entomologist Kenneth Ross of the University of Georgia in Athens. A ninth invasion probably hopscotched from the South to California before hitting Taiwan.

“It’s not good news,” Ross says. These waves of ants are now colonizing the Caribbean, Australia, New Zealand, Taiwan and China, including Hong Kong and Macau, he and his colleagues report in the Feb. 25 Science.

“This study is going to cause quite a stir,” says geneticist Michael Goodisman of Georgia Tech in Atlanta, who studies a different internationally invasive ant. The new fire ant study, he notes, “could have important trade and travel implications.”

Regardless of any furor, the study is a valuable step in dealing with the problem, says another invasive-ant biologist, Ben Hoffmann in Darwin, Australia, with the country’s CSIRO research service. “We need to know how invasions spread to be able to prevent spread and effectively manage invasions.”

Biologists had certainly considered this United States–bridgehead scenario of invasions, Ross says, “but without data, it was anybody’s guess.” To track the invasions, an international research team analyzed ants from 2,144 colonies in a total of 75 places in 11 countries and looked at several kinds of genetic information, including dozens of DNA markers.

“Most studies don’t come close to those numbers,” says Goodisman.

Ross explains that looking closely at fire ants in their native range in South America revealed 322 distinct genetic types. Only 11 of those types were found in the southern United States, including three that were very rare in the native range. Yet the populations from newly invaded territories had combinations of the three rare variants from those U.S. types, not the others left behind in South America. Additionally, the researchers ran computer models of how gene patterns in populations change as invaders bud off into new territories. The scenarios that fit the data best, alas, showed the United States as the source, Ross says.

This analysis raises the possibility that the rigors of invading the United States and then of moving on toward world domination have winnowed out weaklings and less invasive ants. Populations now erupting from the United States could be specially adapted as super-invaders, Ross says.

Even if the insects don’t have special adaptations, basic fire ant biology gives the species some tricks for traveling, Ross says. In the ants’ native range, they survive flooding by fleeing their nests with their young and gripping each other to create a living raft of ants that floats until the flood subsides. If they’re afloat for longer than they can survive without food, adults eat the young. Such a capacity for fasting allows fire ants to endure days or even weeks as international stowaways in any kind of cargo.

For in-country travel, young fire ant queens flying off to find mates may end up wafting onto trucks or other ground transportation that take the queens on detours. Aerial queens can reach substantial numbers, Ross says. “We can go into a parking lot and collect 5,000 of them in an afternoon.”

Florida Ant Control Services

Fire ants have gained a painful foothold in South Florida

Fire ants have gained a painful foothold in South

By Sherry Boas

Red imported fire ants infest more than 275 million acres of land in the United States and Puerto Rico and inject their venom into millions of people annually, according to a University of Arkansas report.

Given the choice of wearing shoes or not wearing shoes, I always opt for going barefoot.

But being barefoot is dicey in a state where the potential for ant bites is great. Floridians whose unshod feet touch the ground are apt to come home with painful stings inflicted by a tiny insect with a long name: Solenopsis invicta Buren.

Nicknamed RIFA, for red imported fire ant, it’s one of two species of fire ants that live in the Sunshine State. The RIFA is widespread, but Florida is also home to a less common species known as the native or tropical fire ant. Neither of the species takes kindly to being stepped on, and they respond to such unwarranted behavior by attacking mercilessly.

If you spend any time outside, you know what I mean. According to a University of Arkansas report, these powerful dirt movers infest more than 275 million acres of land in the United States and Puerto Rico and inject their venom into millions of people annually.

Although we call them ant bites, what we really experience are painful stings.

Fire ants grab the attacker’s skin with their strong mandibles to inject a venom that causes an immediate, localized pain. Within minutes, a red, raised spot usually develops, followed a day later by a white, pimple-like pustule that itches like crazy.

Because each ant can sting repeatedly — and because several ants often attack simultaneously — multiple stings are the norm. It’s not uncommon to run away from a fire-ant encounter with dozens of stings.

Ubiquitous as fire ants are in our lawns, fields, driveways and sidewalks, they were not always a part of the Florida landscape. In the early 1900s, these South American natives made their way into the southern United States by way of cargo ship. Early seafaring vessels used soil as ballast, and it’s likely the dirt-dwelling ants came aboard inadvertently and were then unloaded in America.

Once here, the ants prospered. Colonies multiplied and spread rapidly. Red, imported fire ants now populate every county in Alabama, Florida and Louisiana. They exist in parts of Arkansas, Georgia, Mississippi, Oklahoma, North Carolina, South Carolina, Tennessee, Texas and Puerto Rico. They have even made their way to California, Missouri and across the Pacific to Hawaii.

The insidious fire ants can’t tolerate cold. If temperatures drop to freezing for more than a couple of weeks, the ant colonies die. Fire ants dig into their complex underground burrows for protection. Although they don’t hibernate, they are increasingly less active when it’s cold outside.

Although it isn’t exactly barefoot weather, winter is the safest time to venture outdoors shoeless in Florida. I mention that because as of this past week — if judged by fire-ant activity — winter is officially over. My feet are proof. At the start of the week, I was going barefoot, but by the end of the week, I wasn’t. My toes were so dotted with ant bites that I refused to leave the house without some sort of foot covering.

From an entomological point of view, fire ants are fascinating critters. They have complex social systems, unbelievable strength and an impressive ability to adapt to a broad range of environments. But that doesn’t mean I have to like them.

The bottom line is that these small insects with the big sting are painfully annoying, practically impossible to avoid and incredibly difficult to eradicate. The best we can do is tread carefully and keep a spray bottle filled with vinegar handy. If applied immediately, white vinegar helps quell the discomfort of a fire-ant attack.

Being barefoot may be my preferred state, but practicality trumps preference when it comes to fire ants. I may hate shoes, but I love the way they protect me from ant bites.

Ants: The Spring House Guest No One Wants, But Nearly Everyone Gets

Springtime is ant time as ants march into homes in search of food. With more than 700 species of ants in the U.S. and about two dozen classified as pests, many homeowners will likely encounter these unwelcome visitors.

“Ants are more than a nuisance. They can contaminate food, bite when threatened and damage our property,” noted Missy Henriksen, vice president of public affairs for the National Pest Management Association. “However, which species of ant invades can depend on geography.”

Here are some species homeowners should lookout for this spring:

Odorous house ants get their name from the strong, rotten coconut-like smell they give off when crushed. Odorous house ants like sweets and are found in exposed soil and wall cracks in every region of the U.S.

Carpenter ants typically tunnel into soft wood to build their nests and need a constant water source to survive. This species is found across the U.S. and can cause significant property damage.

Red imported fire ants will build their nest mounds in landscape areas or near structural foundations. The sting of a red imported fire ant is painful and often results in a welt and can cause severe allergic reactions. These ants are most common in southern states.

Argentine ants are found in southeastern parts of the U.S. and California. Argentine ant colonies can grow to monumental size. The ant gives off a musty odor when crushed. They prefer to eat sweets, but will eat almost anything including meats, eggs, oils and fats. Argentine ant colonies are located in wet environments near a food source.

Crazy Rasberry ants, first found in Texas in 2002, have spread to Mississippi and Louisiana and could spread to other southern states. They feed on plants, insects, and small animals, can bite humans, and are oddly attracted to electrical equipment.

Courtesy of Pest World

Introducing the Termite & Ant Institute

BASF (The world’s leading chemical company) has recently launched a couple of very useful, informational websites for consumers. The Ant Institute is a site dedicated to relaying vital ant control information to home owners. The site features great tips on how to avoid an ant infestation, and also contains facts about colony behavior, and the biology of ants. Another cool aspect of the site is it has an ask the expert feature, which is always a useful resource. Remember, you can always ask us about your pest & termite control questions.

The other site BASF recently launched is The Termite Institute. The site has many similar aspects as the ant institute does except the focus is on termite inspection & control. The site provides homeowners with many answers to questions that people constantly have about these common invaders. You can find the answers to questions such as…

Can termites tunnel through cement?

Does homeowners’ insurance cover the cost of termite damage?

Can I treat my termite infestation myself?

You can also find a useful termite identification chart to help you identify this particularly annoying pest. Be sure to let us know what other pest and termite control resources you use when looking for a professional to protect your home and family.

Siafu Ants

Siafu ants, also known as Driver Ants are one of the most dangerous ants in the world.

Colonies of driver ants can number up to 22 million. Almost daily, swarms embark on raids for food which can be brought back to the nest. Although totally blind, driver ants have no problems getting around. They rely on touch, smell and chemical signals from the abdomen of the leading ants. The swarms can travel at up to 20 meters per hour, stripping all animal life in their path. They are also known to raid the nests of other social insects, although never those of other driver ants. They do not rely on stings to attack; rather they use their large and powerful mandibles to create puncture wounds and tear off sections. Driver ants have a larger impact on their habitat than any other creature and they have to move location at regular intervals to find new feeding grounds. During their nomadic existence they form temporary nests called ‘bivouacs’ made from the living members of the colony, in which they house the developing grubs. Whenever the ants swarm or migrate, they form large highways of workers, bordered by the soldiers, which hang over the action, their mandibles waving, to protect the colony as it moves.