Over the past few years, the topic of zombies has been gaining more and more popularity. Increasingly, flash mobs of the walking dead are organized, films and TV series are made, video games, comics, toys, etc. are released. But few people know that zombies really exist, though not in the form we used to imagine them. They can be found in tropical forests: ants and other small insects. They become zombies after being overtaken by Cordyceps, the mushroom that controls their body.
The affected insect, in this case an ant, leaves its colony and settles on a tree leaf. After the victim takes a comfortable position for the manipulator, the mushroom begins to germinate through his body and head.
A similar phenomenon became the basis of the plot of the video game "The Last of Us" by Naughty Dog, where a mutated cordyceps infected humanity.
Let's find out more about this mushroom …
In nature, there is a parasitic fungus that makes carpenter ants follow its "orders", turning them into weak-willed zombies. We are talking about a parasite called cordyceps unilateralis (Cordyceps unilateralis). Usually, the spores of this parasitic fungus get on the ant's body and grow inside its body. This whole process is accompanied by the release of certain alkaloid substances into the ant's body, which make the ant forget about its needs and completely submit to the parasite. Ants affected by this fungus leave their anthill and begin to wander alone, looking for the most favorable place for the life of their owner.
This is precisely the main goal of the one-sided cordyceps - with the help of the ant to get to the best place where it could continue to grow. Since this parasite cannot grow either high in the crowns of trees, nor on or close to the ground, the ant is given the command to find a place where the temperature and humidity are ideal for the fungus to reproduce. When a suitable place for the parasite is found, the ant dies, and a fungus grows from its head, forming a box with spores. The spores, crumbling, fall on other ants, which will soon suffer a certain fate.
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Scientists have recently discovered that this fungus has been parasitizing for 48 million years, as evidenced by fossils found at the site of the former German crater Grube Messel.
In addition, parasites like Cordyceps turn other creatures into zombies as well. For example, the parasite Toxoplasma gondii, which causes toxoplasmosis in humans, controls its intermediate prey, mice. It usually interferes with the work of certain parts of the mouse's brain, depriving it of its fear of being eaten by a cat.
One-sided cordyceps is one of the entomopathogenic fungi. These are fungi that only infect insects. Some fungi can infect arthropods (spiders, for example), but this is rather an exception to their rule. Cordyceps one-sided affects only ants, and only one species - Camponotus leonardi. The fungus can infect other closely related ant species, but with less reproductive and manipulative success.
It is not clear exactly how the spores of the fungus get inside the ant. Most likely, infection occurs through the pores in the cells, or through the cuticles. After entering the body, cordyceps yeast begins to actively multiply in it and spread throughout the ant's body. Presumably, the spores of the fungus form active chemical compounds that affect the ant's brain, changing its behavior.
The ant leaves its colony and descends to the ground (this species of ants lives in trees). The insect chooses a low blade of grass, climbs onto it and very firmly attaches itself to the central vein of the leaf. The ant grasps the plant with its powerful jaws with maximum force and neither wind nor rain can push it. After that, the ant completely loses control over its body and no longer moves. He is not dead yet, but nothing can be done.
Gradually, the fungus kills the ant, and continues to grow. Its roots have already penetrated the soft tissues of the insect, passed through the entire body and firmly fixed on the leaf. Now all that remains of the ant is a large mycelium of the one-sided cordyceps. Immediately, the fungus begins to produce a strong antimicrobial agent to protect itself from small scavengers. When the mushroom is firmly fixed, it sprouts upward through the ant's head. The growth process takes 4-10 days.
Changes in the behavior of infested ants are very specific. Infected insects are called "zombie ants". They suffer from severe cramps, due to which they fall from trees and cannot find their way to their nest. Instinctively striving upward, ants climb on low plants and grass, where they find their last refuge. If the animal cannot climb the grass, then the fungus stops growing, or the growth is accompanied by various anomalies. But the animal dies anyway.
One-sided cordyceps is capable of destroying an entire colony of ants. Insects have developed the ability to sense infected fellows and drive them out of their colony. If the fungus enters the nest, then the infected ant is dragged away so that the whole family does not die from the epidemic. The average density of fungus infestation is 20-30 individuals per m2.
Cordyceps one-sided contains various known and unused biologically active metabolites, and is being investigated as a new source of drugs with immunomodulatory, antitumor, hypoglycemic and hypocholesterolemic properties.
Entomopathogenic fungi are parasitic fungi that attack insects. Sometimes used in agriculture as a pesticide to control the number of harmful insects.