Mysterious parasites on zombie ant mushrooms identified by scientists | CNN

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All over the world, a parasitic fungus is turning ants into “zombies”.

The fungus looks like something out of a horror movie: the organism hijacks the body and brain of its host ant, mentally controlling it to abandon its nest and climb a nearby tree.

There, the infected ant clamps its jaws around a leaf, suspended above the forest floor, and dies within days when the fungus digests it. Bursting through its host’s body, the fungus then sends a shower of spores to infect the next generation of ants.

Scientifically classified in the genus Ophiocordyceps, the more than two dozen species of zombie ant fungi inhabit the world, including Florida, Brazil, and Japan; scientists suspect that each of the dozens of affected ant species has its own specialized strain of Ophiocordyceps.

So far, scientists have uncovered the molecular mechanism of parasitic fungus-ant interaction that forms the basis of behavioral manipulation, according to a 2020 study. However, how exactly these parasites systematically operate is poorly understood. .

Now, scientists have revealed that the fungus attacking ants is infected with its own fungal parasites, which could help control ant zombification, according to a new study.

Dr. João Araújo, assistant curator of mycology at the New York Botanical Garden, has been scouring rainforests for zombie ants for more than a decade. Over the years, he noticed something strange: a fuzzy white mushroom growing above the zombie ant mushroom.

Other scientists have noted the mystery fungus for decades, but Araújo and his colleagues decided to become the first scientists to systematically dig into the question, focusing on a strain of Florida zombie ants. Researchers described the physical structure of fungi growing on top of the zombie ant fungus and sequenced their DNA in a study published Nov. 9 in the journal Persoonia.

In doing so, the team discovered two new genera of fungi previously unknown to science.

“We realized that there were two different strains of fungi, new strains of fungi, infecting a species of zombie ant fungus in Florida,” said Araújo, the study’s lead author.

Each of the two newly discovered mushrooms belongs to its own genus. One of the new fungi, Niveomyces coronatus, is responsible for the fuzzy white coating on the zombie ant fungus – a component of its name (“niveo”) comes from the Latin for “snowy”. The second new fungus, Torrubiellomyces zombiae, is more difficult to spot: the small black spots “look like fleas”, according to Araújo.

The fungi that attack the zombie ant fungus do not zombify their host, but they feed on its tissues and appear to harm it. “Every time we see these new genera that we’ve described growing on the mushroom, the mushroom looks pretty battered, really consumed by this other mushroom,” Araújo said.

“In some cases, it first castrates Ophiocordyceps (the zombie-making fungus) so it can’t shoot the spores anymore, then it grows and then consumes the whole fungus.” Since Niveomyces and Torrubiellomyces are so new to science, it’s not yet known how much of an effect they have on zombie ant fungus populations as a whole.

These new genera are the first parasites officially described as infecting the zombie ant fungus, but researchers suspect there may be others. “I think it’s more common than you think. Parasitism is a super lucrative way of life,” said the study’s lead author, Dr Charissa de Bekker, assistant professor at Utrecht University in the Netherlands. “It is perhaps the most dominant way of life on the planet.”

Also, she says, parasites in general and parasitic fungi in particular are understudied. “The fact that we had to invoke two new genera tells you how little we know about this part of the fungal tree of life,” de Bekker said.

By deepening our understanding of the zombie ant fungus, the new research could have applications that go beyond the study of fungi, said Dr. Carolyn Elya, postdoctoral fellow in organismal and evolutionary biology at Harvard University. She did not participate in the study.

“Over time, Ophiocordyceps has become an expert neuroscientist. It knows exactly which buttons to press and how to get the ant to do what it wants,” she said. “By studying how to solve this problem, we can gain insight into our larger goal of trying to understand how the brain works or produces behavior.”