The parasitic fungi in the Cordyceps genus are a favorite subject of nature documentaries. They've also infiltrated popular culture via the zombie-apocalypse video game The Last of Us (2013) and its TV adaptation, in which a parasitic fungus mutates to infect humans. Scientists are keen to study Cordyceps to learn more about the origins and intricate mechanisms underlying these pathogen-based diseases.
The latest finding: DNA analysis revealed the same fungus in both parasitized insects and surrounding mosses, according to a paper published in the journal IMA Fungus. (Yes, really.) This suggests a second life stage during which the fungus lives inside the moss, possibly an evolutionary adaptation to survive when insect hosts may be scarce. It could also explain why the host species seems to prefer biting into mosses during their final death throes.
As we've previously reported, there are more than 400 different species of Cordyceps fungi, each targeting a particular insect species, like ants, dragonflies, cockroaches, aphids, or beetles. The spores attach to the target insect, such as a carpenter ant, and germinate, spreading through the host’s body via long tendrils called mycelia. Cordyceps essentially turns its host into a zombie slave, compelling the ant to climb to the top of the nearest plant and clamp its tiny jaws in a death grip around a leaf or twig.
Scientists working in the jungles of Borneo report an unsettling discovery: a parasitic organism that they say has a hunger for zombie fungi.
This “hyperparasite” fungus thrives, according to Malaysian scientists behind the discovery, by feeding on forms of fungi that are known to infect insects and temporarily take control of them before ultimately killing them.
The unusual fungus was discovered during field trips by researchers with the University of Malaysia Sabah’s Institute for Tropical Biology and Conservation, who have designated it a hyperparasite because of its unique strategy of feeding through parasitizing another parasite organism.
A Hyperparasitic Zombie-Killer
“The fungus belongs to the genus Pleurocordyceps and acts as a specialized hyperparasite,” said Jaya Seelan Sathiya Seelan, the institute’s deputy director, in a statement provided to AFP last week.
In the television show and related video game series, The Last of Us, a unique approach to the idea of a zombie apocalypse is presented, where humans can become infected by a novel variety of cordyceps. Fortunately, in real life, these parasitic fungi only manipulate insects by hijacking their nervous systems and temporarily taking control of their bodies for a time.
Above: A wasp that has become parasitized by cordyceps (Image Credit: Erich G. Vallery/USDA Forest Service, United States/SRS-4552, Bugwood.org/Wikimedia Commons CC 3.0).
The infected insects begin engaging in erratic behavior as the parasitic fungus takes hold, which eventually fills their bodies and then bursts out in a final, gruesome death for the unlucky host.
A Horned Hyperparasite
The newly discovered “hyperparasite,” Pleurocordyceps cornusynnemata, garners its name from a distinctive horn-shaped appearance, and works by targeting insects—namely tropical ants—which have already been infected by a variety of zombie fungus known as Ophiocordyceps.
“Rather than manipulating the insect’s nervous system itself, Pleurocordyceps infiltrates and feeds directly on the thriving Ophiocordyceps tissue inside the host,” Seelan recently explained, adding that the unique fungus was discovered while investigating a dead ant specimen that was collected from the Danum Valley in southern Sabah.
Although Pleurocordyceps cornusynnemata is not the first hyperparasite fungus known to science, Seelan said it is the first recognized by science possessing its distinctive horn-shaped structure.
The research team with the University of Malaysia Sabah’s Institute for Tropical Biology and Conservation also says they discovered a new species of fungus that similarly attacks and kills spiders by spreading its invasive spores throughout their bodies before death.
Parasites with Promising Potential
Despite their unsettling parasitic nature, scientists are very intrigued by cordyceps. One reason is that these fungi that can hijack and “zombify” the nervous systems of some insects also possess a range of health benefits when consumed by humans, which include boosting energy and athletic stamina, as well as supporting immune function and helping to reduce inflammation.
“These newly documented fungi hold immense potential,” Seelan told AFP, “both as sources for developing next-generation antimicrobial drugs and as highly effective biocontrol agents against agricultural pests.”
The team’s findings were published in a recent study, titled “Taxonomy and phylogeny of Pleurocordyceps (Polycephalomycetaceae, Hypocreales) associated with ants and cicadas from Malaysia, including a new species and new records,” which appeared in the journal Phytotaxa.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached atmicah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.
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