What Is Zombie Fungus
Ophiocordyceps unilateralis sensu lato - a complex of species sometimes called the "zombie ant fungus" - surrounds and invades muscle fibers throughout the ant's body, and fungal cells form a three-dimensional network that allows them to collectively control the host's behavior. - said the researchers.
The fungi attach to plants and release antibacterial chemicals to protect themselves, and grow fruiting bodies from the ants' heads to release their spores, producing the next generation of fungi.
It has been known to infect and destroy entire carpenter ant colonies, leaving behind a dense, well-ventilated graveyard of ant carcasses. A parasitic fungus, for short), infects the brains of wood ants, turning them into zombies that live and die in order to help the fungus thrive and reproduce.
Under the influence of the fungus, carpenter zombie ants leave the nest at a strange but determined time, moving in chaotic and convulsive movements, climbing exactly 25cm along the north side of the plant, where they bite into the veins of the leaves.
The fungus eats the internal organs of ants, using their shells as a protective coating. The main stem of the fungus (stroma) grows out of the nape of the ant and grows.
When a fungus first enters its host, it exists as individual cells that float in the ants' bloodstream, producing new copies of themselves.
The fungus grows throughout the ant's body cavity, using the internal organs as food, while the ant's durable exoskeleton acts as a kind of capsule, protecting the fungus from drying out, ingesting, or further infection.
Researchers believe that a fungus found in rainforests infects forage ants through spores that attach to and penetrate the exoskeleton, gradually changing their behavior. A few days after the ant dies, the fungus sends a fruiting body across the base of the ant's head, transforming its withered corpse into a stepping stone from which it can dump its spores and infect new ants.
As with the zombie legends, there is an incubation period where the infested ants appear perfectly normal and go about their business unnoticed by the rest of the colony.
If this is a deliberate act of the ant, it can save the rest of the colony from contracting an infection sometimes called "adaptive suicide."
It is unclear if this behavior is a zombie condition caused by a fungus or an altruistic act of self-sacrifice on the part of the ant. In other words, the parasite takes over the ant's mind, forcing it to feed on other insects.
First, it affects the behavior of ants through convulsions, due to which they fall from their nest under a canopy high on the forest floor. First, it releases spores, which are then carried through the air until they reach the ant (Lu, 2019).
A stem then grows that releases spores from the back of the victim's head to infect more ants on the ground below. Once the mushroom kills its unfortunate drone, a stem grows that releases spores from the ants' heads to infect even more ants.
When the fungus releases spores, it creates what the authors describe as an “infectious extermination camp,” about one square meter below the ant's body, which can infect C. leonardi ants or similar species that are unfortunate enough to walk in it.
Other fungal parasites also control their insect hosts as if they were zombies. This means that after the death of the ant, the fungus can continue to grow and then leave the ant's body, sometimes in the form of fungal stems.
Thus, the fungus benefits from this because the infectious spores end up underground where they can infect other drill ants.
New research shows that the fungal parasite does all of this without infecting the ants' brains. Meanwhile, "the cuticle of ants ... is transformed into a protective shell by strengthening the weaker parts," and the parts of the fungus in the ant's body appear to differ in individual functions, the researchers write.
The team found that ants infected with the fungus climb high places and bite into vegetation, permanently entrenched.
After a leaf bite, the infected ants always died, since this is necessary for the subsequent growth of the fungus. It has since been found that the fungus disrupts the ant's normal behavior by chemically interfering with the brain, causing the infected ant to behave in a way that improves the fungus's ability to spread its spores and then reproduce.
The fungus that invades the ant's body is known as the genus Cordyceps and includes many species of fungi. This connection between ant and fungus is obviously ancient, but it is also very common: to date, about 1000 species of fungal insect parasites have been discovered.
In addition, it has been suggested that their morphological variations may also be the result of the fungus species maximally infecting a particular host ant species (host-specific infections).
In 2011, it was suggested that the zombie ant fungus could in fact be described as a host-specific species complex, meaning that one O. unilateralis species can successfully infect and manipulate only one host ant species.
There has been a lot of controversy over whether zombie ants (and other mushrooms) belong to one or the other, since Ophiocordyceps was introduced very recently. We found that the zombie ants were likely descended from an ancestor that infected the larvae of beetles living in decaying soil or wood, similar to the Ophiocordyceps species that infect existing beetles.
Surprisingly, the leap has resulted in widespread species radiation observed after the development of behavioral manipulation. The authors also studied the effect of the fungus on the ant of the genus Polyrhachis and found that not all of its manifestations were reported.
The team injected the fungal material (in liquid medium) into two species of ants, Camponotus pennsylvanicus and Formica dolosa, who, despite living in the same area as other ants, were not known to carry the fungus.
The team placed several ant colonies in the lab, infected some with the fungus, and watched as the ants got sick and violently blocked anything they might find. The control group was infected with a single fungus, Beauveria bassiana, which also killed the ants without causing death.
All of these individuals exhibited seizures that were unevenly distributed throughout the body (vertical bars in the periodogram in Figure 1), which often resulted in ants falling from vegetation to the ground (indicated by asterisks in the periodogram).
To see how important this precision is to the fungus, the researchers identified dozens of infested ants in a small patch of forest. It was confirmed that all 21 zombie ants we observed were infected by dissecting the head to detect fungal cells or by observing the emergence of O. unilateralis s.l.
What Does Zombie Fungus Do?
While a simpler argument was enough to fool the more solitary insects, the public ants could easily alert their colony and move on, which meant that poor old Cordyceps had no choice to adapt to anything that could mimic. ant behavior. the colony.
The research team placed several ant colonies in the laboratory, infected some groups with the fungus, and watched the ants get sick and violently suppress any objects they might find. Control groups were infected with a separate fungus, Beauvaria bassiana, which also kills ants without causing a death grip.
They analyzed the growth rate of five cemeteries containing the carcasses of ants infected with Ophiocordyceps camponoti-rufipedis, located in a 400-hectare nature reserve in the Brazilian rainforest.
The researchers then collected 31 dead parasitic ants carrying mature spore-forming fungi, along with the leaves to which they were attached, and returned them to the laboratory to measure how quickly the cordyceps reproduced.
The team injected fungal material (in a liquid medium) to two ant species, Camponotus pennsylvanicus and Formica dolosa, which are not known to host the fungus despite living in the same areas as other ants.
The team also observed strange vesicle-like particles attached to infected tissue, although it is unclear if they were produced by a fungus or a host ant.
The team found that fungus-infested ants climb high places and bite vegetation, fixing themselves permanently. The behavior is to bite the leaf so hard that this prevents the ant from falling, as it dies while hanging upside down, which therefore allows the fruiting body of the fungus to grow properly.
After the fungus enters the ant, it multiplies and the fungal cells are located near the host's brain. As the fungus grows into the ant's carcass, it forms a stem that protrudes from the ant's head and drops infectious spores to the ground below, where they can infect other foraging ants.
Researchers believe that a fungus found in rainforests infects forage ants through spores that attach to and penetrate the exoskeleton, gradually changing their behavior.
As the infection progresses, the enchanted ant is forced to leave its nest in a more humid and favorable microclimate for the growth of the fungus.
The fungus forces the ant to climb vegetation and cling to a leaf or branch before killing the unfortunate algae. Once the fungus kills its unfortunate drone, a stem grows that releases spores from the ants' heads to infect new ants.
A few days after an ant dies, the fungus forms a fruiting body at the base of the ant's head, turning its shriveled carcass into a stepping stone from which it releases spores and infects new ants.
The fungi attach to plants and release antibacterial chemicals to protect themselves, and grow fruiting bodies from the ants' heads to release spores, which give rise to the next generation of fungi.
It has been known to infect and destroy entire carpenter ant colonies, leaving behind a dense, airy graveyard of ant carcasses. A parasitic fungus, for short), infects the brains of carpenter ants, turning them into zombies, and it's a matter of life and death to help the fungus thrive and reproduce.
Under the influence of the fungus, carpenter zombie ants leave their nests at a strange but determined time, moving chaotically and spasmodically, climbing exactly 25 centimeters along the plant's north side, where they penetrate deep into the leaf veins.
The devouring fungus forces the ant of the species Camponotus leonardi to “grasp deathly” on the underside of the leaf, which is a privileged position for the transmission of the fungus. This mushroom corpse thief drives the ants into the undergrowth of the forest and forces them to climb vegetation and bite the underside of leaves or branches where the ants die.
Satisfied with the chosen place, a tendril is violently pulled out of the heads of its victims, throwing its spores at any other ant that is not lucky enough to be nearby. Cordyceps essentially transforms its master into a zombie slave, forcing the ant to climb to the top of the nearest plant and clench its death grip around a leaf or branch with its tiny jaws.
All this time, the fungus continues to grow and makes up almost half of the ant's body weight. It turns out that the zombie ant fungus itself parasitizes on another fungus, which limits its ability to reproduce and prevents it from invading the colony.
As soon as the infectious hyphae pierces the exoskeleton, avoiding the cellular and humoral protection of the ant, the fungus grows in the hemocele in the form of free-living yeast cells. The parasite will feed on the creature and grow for several weeks, so it can release more spores and infect more insects.
So while a large number of individual ants are infected, the fungus it contains has a very small chance of producing spores that can survive and infect other ants.
So the fungus wins because the infectious spores reach the ground below, where they can infect other foraging ants. Other fungal parasites also control their insect hosts like zombies. It also activated some genes that suppress the ant's immune system, clearing the way for fungal cells to grow and multiply in the ant's head tissue.
We hypothesize that the mushroom can preserve the brain so that the host can survive until it completes its final bite, a critical moment for the mushroom to reproduce.
This suggests that the fungus expresses its mind control through biologically active compounds that act on the ants' nervous system and control their hosts directly through the muscles, de Becker says.
Researchers in Thailand and the United States are studying different types of ophiocordiceps that infect other ant species to compare their control mechanisms. In addition, it has been hypothesized that their morphological variations could also result from a fungal species maximizing its infection on a particular host ant species (host-specific infections).
In 2011, it was suggested that the zombie ant fungus could in fact be described as a host-specific species complex, meaning that one species of O. unateralis can successfully infect and manipulate only one host ant species.
There has been a lot of controversy over whether zombie ants (and other mushrooms) belong to one or the other, since Ophiocordyceps was introduced very recently. Known as cordyceps, this deadly fungus can kill entire species. The spores secreted by parasitic fungi of the cordyceps group infect host insects, causing the fungus to grow inside them.
The fungus Ophiocordyceps unateralis sensu lato does not affect the brain, but it affects the muscles of the ants, causing them to contract excessively. These interactions are likely to be the cause of death, scratches and bites, because the fungus does not actually attach directly to the brains of the infected ants.
Instead, the new work shows that zombie ant fungi surround and invade the muscle fibers of the entire ant's body.
These images clearly show that the filaments of the fungus are invading the muscle tissue, but the neuromuscular junctions through which the nerve signals from the brain are transmitted to the muscles to control muscle movement remain intact, indicating that the fungus does not directly affect the brain. Infected ants. ...
