Alien mad ants threaten native animals in Texas

An alien species of ant with the ability to secrete toxic formic acid is invading Texas, threatening native animals.

Native to Argentina and Brazil, the Tawny mad ant (Nylanderia fulva) has "hitched" a ship across the ocean to the US and quickly proliferated. They are swarming the new expanses of Texas, killing insects and lizards, driving away birds, and even blinding baby rabbits by spraying acid in their eyes.

Nylanderia fulva is known as the mad ant because of its erratic movement, unlike its "orderly marching" relatives. Although not venomous like fire ants, Tawny mad ants can secrete formic acid to defend themselves against predators or render native animals unable to reproduce.

"It was a horror scene," ecologist Edward LeBrun, who has described swarms of mad ants invading Estero Llano Grande Park in Texas, told AFP. "They not only destroy ecosystems but also disrupt human life."

Nylanderia fulva has a tendency to nest on electrical systems, causing short circuit breakers, alternators and sewage pumps. Several control measures for mad ants, including spraying with highly toxic insecticides, have been implemented, but only slow down their growth, but cannot completely destroy them.

Tawny crazy ant is eating a cricket.

However, in a new study published February 28 in the Proceedings of the National Academy of Sciences, scientists at the University of Texas at Austin have brought some good news. They discovered that a naturally occurring fungal pathogen could reverse the rampant madness ant invasion across the southeastern United States.

This fungus is called Microsporidia. It can hijack the fat cells of insects and turn them into "factories" of spores. The origin of the pathogen is unclear, perhaps it came from South America or from another insect species.

LeBrun and his colleague Rob Plowes, while studying crazy ants they had collected in Florida, came across some individuals with unusually swollen abdomens due to fat. The main cause is Microsporidia.

The team observed 15 populations of mad ants over the years and found that all populations that harbored the pathogen were in decline, with up to 60 percent becoming extinct.

In one experiment, the team decided to place infected ants with healthy ones in the same nesting site inside the park, placing sausages around the exit compartments of a box to lure them in. two herds merge.

These ants later formed "super-colonies," meaning separate groups that did not fight each other for territory. This is a huge advantage when mad ants invade new areas, but also becomes their biggest weakness, as it allows pathogens to spread unchecked.

The experiment was a huge success, reducing the number of crazy ants at the park to zero within a few years. Larvae cared for by infected worker ants appear to be very vulnerable.

In the next phase, the team will continue to test their new biocontrol method in sensitive Texas habitats this spring.