Described by entomologists as a puppeteer controlling a marionette doll, the Ophiocordyceps fungus is known to victimize numerous insects by taking control of its entire body. An Ophiocordyceps species is known to use its ant host to infect the rest of its colony. With that said, how does the notorious zombie fungus infect its victims?

Contrary to its name, the zombie ant fungus doesn’t infect the brain of its host to take over their bodies. Entomologists state that the fungus cuts the ant’s limbs off from its brain to directly release chemicals that coerce the ant’s body to move and contract. 

What is the Zombie Ant Fungus?

The Ophiocordyceps unilateralis, most recognized as the zombie ant fungus, depends on ants to continue their life cycle. As ants venture for food and other provisions, they may encounter the fungus’ fungal spores. When an ant steps on the fungal spore, infection will follow suit and spread throughout its body after a fungal cell slips inside.

The Ophiocordyceps will consume the ant internally while multiplying into new, numerous cells. No external manifestations would hint that all of this is happening. The ant would continue with its life, hunting for food to return to its ant nest as the fungus within its body is continually growing until it amounts to half of the ant’s body weight.

After the fungus consumes everything it needs from its host, all the fungal cells would combine inside the ant’s body. The gathered fungus cells would then form themselves into a mat and shove needlelike projections into the ant’s muscle cells. Finally, the ant’s brain would receive chemical signals from the fungal cells and make the ant leave its nest to climb and chop down on a nearby plant. (Source: The New York Times)

It stops the ant at a height of 25 centimeters—a zone with precisely the right temperature and humidity for the fungus to grow. It forces the ant to permanently lock its mandibles around a leaf. Eventually, it sends a long stalk through the ant’s head, growing into a bulbous capsule full of spores. And because the ant typically climbs a leaf that overhangs its colony’s foraging trails, the fungal spores rain down onto its sisters below, zombifying them in turn.

Ed Yong, The Atlantic

(Source: The Atlantic)

The Inner Workings of the Ophiocordyceps

The fungus enters its host initially through single fungal cells. With that said, the single cells remain suspended in the ant’s bloodstream as they sprout new single cells. The single cells soon collaborate and construct short tubes to connect themselves, permitting the exchange of nutrients and communication. The fusing of the single fungal cells forms a superorganism that can even control the brains of larger animals.

In addition to that, the single cells can pervade the ants’ muscle cells by growing into the existing spaces between them or by penetrating the muscle cells. The fungus takes over the entire body of its host without infiltrating its brain.

If such parasites were merely invading and destroying neuronal tissue, I don’t think the manipulated behaviors that we observe would be as compelling as they are.

Charissa de Bekker

(Source: The Atlantic)