Armies of super ants that start fires by chewing wire could be wiped out

By Mark Waghorn via SWNS

Armies of super ants that start fires by chewing wire could be wiped out by a naturally occurring fungus, according to new research.

The insects have tiny teeth sharp enough to gnaw through thick cabling - triggering short circuits.

Native to South America, they are covered in red hair. They have been nicknamed "crazy ants"- after their jerky movements.

They bite, sting, spread salmonella - and are a nightmare for homeowners.

The creepy crawlies are also an "ecological wrecking ball" - driving out indigenous insects and small animals.

They can blanket the ground by the millions. At only 0.125 inches (3.2 mm) long, crazy ants are tiny - but mighty.

Their spread has been blamed on the growth of world trade along with the increase in flats and tower blocks - perfect conditions for the insects.

Now scientists have discovered their nemesis - a mould known as Microsporidia.

An analysis of individuals collected in Florida found it swelled their abdomens.

The pathogens had hijacked the insects' fat cells - and turned them into spore factories.

They began turning up at sites across Texas where the crazy ants have been running riot.

Observing 15 local populations for eight years, scientists found every one declined — and 62 percent disappeared entirely.

Lead author Dr. Ed LeBrun, of The University of Texas at Austin, said: "You don't expect a pathogen to lead to the extinction of a population.

"An infected population normally goes through boom-and-bust cycles as the frequency of infection waxes and wanes."

In some parts of the state, homes have been overrun by ants that swarm breaker boxes, AC units, sewage pumps and other electrical devices.

They have raised alarm bells as they’ve spread across the south eastern US during the past 20 years.

The idea for using the fungal pathogen came from observing wild populations becoming infected and collapsing without human intervention.

It either came from the ants' native ranges in Argentina and Brazil - or another insect.

Dr. LeBrun believes the colonies collapsed because it shortens worker ants' lifespan - making it hard to survive through winter.

What's more, the pathogen appears to leave native ants and other arthropods unharmed - making it a seemingly ideal biocontrol agent.

Six years ago Estero Llano Grande State Park in Weslaco, Texas, was losing its insects, scorpions, snakes, lizards and birds to crazy ants.

Baby rabbits were also being blinded in their nests by swarms of the acid-spewing insects.

Dr. LeBrun said: "They had a crazy ant infestation, and it was apocalyptic, rivers of ants going up and down every tree.

"I wasn't really ready to start this as an experimental process, but it's like, OK, let's just give it a go."

His team put infected ants collected from other sites in boxes near nesting sites in the park.

Hot dogs were placed around the exit chambers to attract the local ants - and merge the two populations.

The experiment worked spectacularly. In the first year, the disease spread to the entire crazy ant population in Estero.

Within two years, their numbers plunged. Now, they are non-existent and native species are returning to the area.

The researchers have since eradicated a second crazy ant population at another site in the area of Convict Hill in Austin.

Dr. LeBrun said: "This doesn't mean crazy ants will disappear. It's impossible to predict how long it will take for the lightning bolt to strike and the pathogen to infect any one crazy ant population.

"But it's a big relief because it means these populations appear to have a lifespan."

The fungus is described in Proceedings of the National Academy of Sciences.