‘Super ants’ that cause fires could be eradicated by a fungus, study says

Armies of ‘super ants’ that suffocate chickens and start fires by chewing wire could be wiped out by a naturally occurring fungus, a study claims.

The forest ant (Nylanderia fulva) is an invasive species described as an “ecological wrecking ball” because it repels native insects and small animals.

According to experts, they not only eliminate populations of other ants, but can also kill chickens by blocking their nasal passages, causing them to die of suffocation.

Multiple tawny mad ants also accumulate in electrical equipment, causing short circuits and clogging of switching mechanisms, resulting in equipment failure and fires.

The species — dubbed “crazy” for its fast, unpredictable movements — originated in Argentina and Brazil, but over the past 20 years has caused chaos as it spreads across the US.

Now, researchers in Texas have shown how to use a naturally occurring fungus called microsporidia to decimate local populations of mad ants.

Microsporidic pathogens usually hijack an insect’s fat cells and turn them into spore factories.

The tawny mad ant (Nylanderia fulva, pictured) is an invasive species described as an ‘ecological wrecking ball’

Multiple tawny mad ants also accumulate in electrical equipment, causing short circuits and clogging of switching mechanisms, resulting in equipment failure and fires.  Here tawny ants swarm on a cobweb spider

Multiple tawny mad ants also accumulate in electrical equipment, causing short circuits and clogging of switching mechanisms, resulting in equipment failure and fires. Here tawny ants swarm on a cobweb spider

THE BIZARRE TAWNY CRAZY ANT

The tawny crazy ant (Nylanderia fulva) is a species of ant native to South America.

The species has fast, unpredictable movements and a reddish-brown color. It is about one-eighth of an inch long.

The tawny mad ant is different from other common ant species in that they do not have a stinging mechanism used for protection.

So instead of stinging, the species emits chemical compounds that protect them from attack by other insects. Although they can cause a bite, these ants cause only mild pain that quickly subsides.

Multiple tawny crazies also accumulate in electrical equipment, causing short circuits and clogging of switching mechanisms, resulting in equipment failure and fires.

The bugs are, bizarrely, attracted to electrical wiring and components, causing $146.5 million in damage in Texas in one year alone, ABC reported.

The devastation occurs when an ant discovers the transformer and is then electrocuted when it touches it, and “waves its belly in the air” and leaves out a certain smell.

The scent attracts ants to the scene and they too are electrocuted, sending the scent back into the air to attract their friends.

Eventually there are so many dead ants that the electrical switches get stuck or the insulation falters and the system goes down.

First found in the US in Houston in 2002, scattered pests can now be found in all Gulf Coast counties.

Individual infestations can be huge, measuring miles in diameter, according to Brackenridge Field Laboratory.

It is sometimes referred to as the “Rasberry Mad Ant” in Texas, after exterminator Tom Rasberry, who noticed the ants increasing in number in 2002.

The study was led by Edward LeBrun, a biologist at the Brackenridge Field Laboratory in Austin, Texas.

In some parts of the state, homes have been overrun by ants that are swarming with circuit breakers, AC units, sewage pumps and other electrical appliances, causing short circuits.

‘I think so [the fungus] has a lot of potential for protecting vulnerable habitats with endangered species or areas of high conservation value,” said LeBrun.

“It’s impossible to predict how long it will take for the lightning bolt to strike and the pathogen to infect a crazy ant population.

“But it’s a big relief because it means these populations seem to have longevity.”

About eight years ago, LeBrun and Rob Plowes, also of the Brackenridge Field Laboratory, were studying crazy ants collected in Florida when they noticed that some had distended their bellies with fat.

When they looked inside their bodies, they found traces of a microsporidian, a group of fungal pathogens — a species new to science.

It is not clear where the pathogen came from, although it may have come from the native range of the tawny crazy ants in South America or from another insect.

LeBrun and his colleagues later found the pathogen in 15 local populations of mad ants across Texas.

Any population that had harbored the pathogen declined, and 62 percent of these populations disappeared completely.

“You don’t expect a pathogen to lead to the extinction of a population,” LeBrun said.

“An infected population normally goes through boom-and-bust cycles as the frequency of infection increases and decreases.”

The ant colonies may have collapsed because the pathogen shortens the lifespan of worker ants, making it difficult for a population to survive the winter.

Fortunately, the pathogen appears to leave native ants and other arthropods unharmed, making it a seemingly ideal means of “biocontrol.”

The team deployed the pathogen in this way after LeBrun received a call in 2016 from Estero Llano Grande State Park in Weslaco, Texas.

The park lost its insects, scorpions, snakes, lizards and birds to tawny ants,” he said. ‘Baby rabbits were blinded in their nest by swarms of acid-spitting ants.

“They had a crazy ant infestation, and it was apocalyptic, rivers of ants going up and down every tree.

Pictured, traces of microsporidia collected from a mad ant's tawny at Pace Bend Park in central Texas

Pictured, traces of microsporidia collected from a mad ant’s tawny at Pace Bend Park in central Texas

“I wasn’t really ready to start this as an experimental process, but it’s like, okay, let’s just try it.”

Using mad ants they collected from other sites already infested with the microsporidic pathogen, the researchers placed infected ants in nest boxes near mad ant nest sites in the state park.

They placed hot dogs around the exit chambers to attract the local ants and merge the two populations.

In the first year, the disease spread to the entire population of mad ants in Estero, Florida, and within two years their numbers dropped.

Now, according to the researchers, the tawny ants are not present in the area and native species are returning.

Edward LeBrun, a research scientist with the Texas Invasive Species Research Program at the University of Texas at Austin's Brackenridge Field Laboratory, collects tawny crazy ants on a field in central Texas

Edward LeBrun, a research scientist with the Texas Invasive Species Research Program at the University of Texas at Austin’s Brackenridge Field Laboratory, collects tawny crazy ants on a field in central Texas

The team has since eradicated a second mad ant population at a different location in the Convict Hill area of ​​Austin.

They now plan to test their new biocontrol approach this spring in other sensitive habitats in Texas that have been infested by mad ants.

Their study is published today in the journal Proceedings of the National Academy of Sciences.

GENETICALLY-TWEAKED INDIAN JUMPING ANTS BECOME ‘SPACE CADETS’

In 2017, scientists genetically engineered ants to lack their sense of smell.

This affected the insects’ ability to communicate, forage or compete to be queens, as their antennae and brain circuitry did not fully develop.

Ants communicate through pheromones (secreted chemicals that trigger reactions).

Such scents are used to sound the alarm when a predator approaches, leave a trail for food, indicate social status and indicate willingness to mate.

Ants can receive such signals because they have proteins called odor receptors on their antennae, with each protein being the correct shape to bind to a specific odorant.

However, to process any odor or pheromone in an ant’s brain, both the correct odor receptor protein and a shared, common partner protein called Orco must be present.

The team successfully engineered the genetic loss of Orco protein, resulting in ants that could no longer perform some, if not all, pheromone-based social interactions.

In particular, unlike their nestmates without the changes, the altered young ants spent much of their time wandering out of the nest. They failed to interact with other members of the colony (a behavior called “space cadet”), and were unable to forage and return food to the nest.

Also, mutated females no longer nursed males, a pre-mating behavior. The current study focused on the Indian jumping ant, Harpegnathos saltator, which is unlike many ant species where only the queen can mate and pass genes on to the next generation.

Any female adult worker of Harpegnathos can be turned into a ‘queen-like’ gamergate in the absence of the queen. This is because the queen secretes a pheromone that suppresses workers’ ability to mate and lay eggs.

If the queen is removed, after winning a series of aerial duels, the most aggressive females undergo this transition and can continue to produce offspring, which is essential for colony survival.

The 2017 study found that the females without Orco cannot process pheromones, making them much less likely to duel.

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