Scientists studying ants that ravaged wildlife in the southeastern United States for 20 years may have found a natural antidote, a fungal-like pathogen, to rid South America of this invasive species.
The study, conducted by researchers from the University of Texas at Austin, was published Monday by the American Academy of Sciences.
Lead author Edward LeBrun told AFP that the fungus has already caused the extinction of pocket ants and will be tested in the spring in sensitive environments in Texas to protect the endangered species.
Tawny crazy ants (Nylandaria fulva, sometimes called raspberry crazy ants), so named because of their erratic movements, come from Argentina and Brazil and were introduced to the United States by boat.
They hunted a more aggressive species of ants, called “fires” because of their venom, which causes painful bites, and attacked animals – scorpions, snakes, lizards, birds – by secreting a formic acid. By doing that also saves them from the poison of their cousins.
“It’s a horror show,” says Edward LeBrun, describing rivers of ants colonizing trees in an area of Estero Llano Grande Park in Texas where local wildlife has disappeared.
They destroy ecosystems but are also “a plague” for humans, underlines the scientist. Ants colonize electrical systems, blowing up meters, air conditioners and pumps.
They only react to very toxic insecticides, which only slows their progress and leaves mountains of dead ants that must be evacuated.
– Trojan Ants –
About eight years ago, Edward LeBron and one of the study’s co-authors, Rob Plows, found that ant carcasses recovered in Florida had an unusually bloated belly with fat.
The analyzes revealed the presence of spores from a species of Microsporidia, a type of pathogenic fungus, which was unknown until then.
Microsporidia usually invade insect fat cells, turning them into spore-producing factories.
The origin of this pathogen is unclear: possibly South America or some other insect.
Still, it is spreading in Texas. Each of the 15 colonies studied declined in population over eight years when the pathogen was detected, and 60% of these colonies died.
As part of their experiments, the researchers introduced pathogen-infected ants to an uninfected colony in a protected area, keeping a hot dog for mixing the two groups.
Mad ants live in “supercolonies” where groups do not fight over territory. This is a major advantage for colonizing new areas, but also their greatest weakness, allowing the pathogen to spread freely.
The experiment was crowned with success, causing the population of this colony to become extinct within a few years. Larvae infected with infected worker ants were particularly fragile.
For Edward LeBrun, there’s two good news: A naturally occurring pathogen specifically targets invasive species, limiting their ability to invade an ecosystem, and scientists may be accelerating the spread of this pathogen. So that you can get rid of crazy ants faster.
But this process will take time and the ants will not disappear overnight, the researcher says.