Nature’s sick reality or Hollywood’s frightening fantasy? As it turns out, mind-controlling predatory organisms are a real threat for the likes of ants and other insects. A specific group of fungi known as Cordyceps can take over the insect’s mind and control the body. Let me repeat: A FUNGUS TAKES OVER THEIR MINDS AND BODIES. How is this even possible!?! Let’s focus on the fungus Ophiocordyceps unilateralis, known across the Internet as “the fungus that makes ants go crazy.” This fungus’s mechanism for life is something you would expect to see in a television show about how the world is ending.
Ophiocordyceps unilateralis is an insect pathogen that was discovered by Alfred Russel Wallace, a British naturalist, in 1859. They are found most often in tropical rainforest ecosystems, probably because eighty percent of all insects live in jungles, the Cordyceps’s main prey. Being a pathogen, the objective for the fungus is too infect as many insects as possible, so the rainforest’s density of insects makes sense to be the place where Ophiocordyceps unilateralis would have the best chance of survival. The fungus releases spores into the forest hoping to infect any insect it can find. All Cordyceps have specific types of insects that they are most potent against, and for Ophiocordyceps unilateralis that specific insect is the Camponotus leonardi ant. The fungus can also infect species of ant that are closely related, but the pathogenic qualities will work at varying degrees of effectiveness.
When a spore lands on the ants exoskeleton, enzymes in the spore work to degrade the hard shell so that it can make its way into the soft body. The fungus makes its way to the ant’s brain and begins to eat away as it takes over the at’s motor skills. Taking control of the ant’s body movement, the fungus climbs up to as high a point that it can get to, bites down on something for steadiness, and kills the host ant. From there, the fungus will begin to grow a piece of mycelium, a long piece of fungus, straight from the head of the host until it eventually shoots its spores into the air, searching for more hosts. The mechanism that the fungus uses to take control of the ant’s body is still unknown, adding a bit of uneasy ambiguity to an already gruesome scene.
The ants have become savvy to the fungi’s efforts though. When a healthy any finds the corpses of an ant infected with Ophiocordyceps unilateralis, the ants makes a point to carry the ant as for as possible from the ant colony to avoid an outbreak. Also, ants evolve quickly and after one generation have already become immune to any specific strain of the fungus. This forces the fungus to move on to another colony if it is going to survive. Eventually though, the fungus will also evolve and be able to successfully infect the colony once again. The zombie-creating fungus is also under attack from another pathogenic fungus, Penn State’s David Hughes tells us. Apparently this newly discovered pathogen, “effectively castrates the zombie-ant fungus so it cannot spread its spores.” And I’m sure this new fungus also has a whole load of forces fighting and aiding it as well, reminding just how complex and absurd our planet is.
As seen in a 48 million year old leaf that seems to have markings on it that are characteristic of the ants final bite marks, this battle between insects and fungi has gone on for a long time with no sign of stopping. The fungus is a scary one, but is generally good for the environment. Having Coryceps around helps to control the population of any particular insect that begins to overpopulate and keeps the natural equilibrium of nature in check. Luckily, in all the years it has been around, Cordyceps have never evolved to infect humans. So sorry if you were hoping for a zombie apocalypse anytime soon. You’ll just have to show off you archery skills some other way.
