The 'zombie ant fungus' can infect ants and bring them under its control, but it leaves their brains uninfected, a new study finds. Researchers say the fungus may have done that on purpose, so as to allow the ants to survive until it performs the last act.
The Zombie Ant Fungus
The zombie ant fungus, also called Ophiocordyceps unilateralis sensu lato, is known to infect "carpenter ant workers" and control them to its own advantage.
When the fungal parasite infects an ant, it takes hold of its entire body and moves it to the lower side of a leaf or a stem. While in that position, the fungus manipulates the ant into performing the last act, which is to bite the underside of the leaf before it eventually dies. After some time, a stalk grows out of the dead ant's head and releases spores to infect other ants once again.
However, one thing biologists didn't understand is how the zombie ant fungus organizes all of this and controls the behavior of the ant.
Biologists And Artificial Intelligence Researchers Team Up To Investigate
Biologists from the Penn State University along with computer scientists from the University of Notre Dame have teamed up in order to discover how the zombie ant fungus is able to control its victims.
The team decided that the best way to study this is by infecting ants with the fungal parasite and developing 3D images of the scenario in order to work out how fungal cells interact inside the ant's body.
After that, computer scientists tried to use AI computers to look at those 3D images and make out the differences between the fungus and the ant.
The Results Of The Study
The results show that the entire bodies of ants were left with fungal cells. This means that the fungal parasite manages to occupy the entire body of an ant through the distribution of its cells.
Researchers also found that these fungal cells inside the ant's body were somehow connected to each other as though they were formed like a network. This may explain how the zombie ant fungus manipulates the ant's body as a whole. David Hughes, an associate professor of entomology and biology at Penn State, said that essentially the ants were like "a fungus in ants' clothing."
Finally, researchers also discovered that, although the fungal cells were highly concentrated in the ants' bodies, including in their heads, legs, abdomens, and thoraxes, their brains did not appear to contain any of those cells. Hughes said that animals usually control their behaviors with their brains, but the results show the zombie ant fungus may be controlling the ants from the outside.
Researchers concluded that the zombie ant fungus may have left the ant's brain untouched on purpose, so as to allow it to survive until the time for reproduction. Researchers say further study is needed in order to determine what role the ant's brain plays and how much power the fungus has over it.
The results were published in the Proceedings of the National Academy of Sciences.