Not A Fungi To Be With . . . If You’re An Ant
Forget the ‘Night of the Living Dead’ and ‘Invasion of the Body Snatchers’, there’s a horror story going on right now, beneath our feet, directed by Nature. You may have already read about it, but it’s so fascinating in its grisliness that I couldn’t let the story slip by without posting it.
Let Me Tell You A Horror Story
In the tropical rainforests around the world, there is a species of carpenter ant called the Camponotus leonardi that lives up in the trees. Unfortunately for them, there is also a fungus in the same environment, Ophiocordyceps unilateralis, that releases spores which infect these unsuspecting ants. It’s not yet know what chemicals are released into the ants from these spores, but what is known is the bizarre and gruesome effect it has on them. The chemicals infect the ant’s brain and take control, leaving the ant in a zombie-like state. The ant, under the control of the fungus, then leaves its colony (something that it would otherwise never do), moves to a particular location on a particular leaf, locks down on the leaf with its jaws and remains there until the fungus kills it. The next scene in this horror story is where the fungus, now living in the ant, produces a long stalk that grows from the ant’s head that shoots out spores in order to infect other passing ants.
Why Is The Fungus Doing This?
Most actions that creatures and plants do in nature are for the preservation and extension of their species. This fungus is no exception. What is it trying (and succeeding) to do is to reach the optimum location for it to live in by hijacking ants as transport and directing them to carry it to a chosen destination. A form of adaptive parasite manipulation. The remarkable thing is that the fungus direct the ants to very specific locations (to a leaf on the north side of a plant, 25cm above ground, that’s in 95% humidity and 20-30 °C). Scientists studying this found that all of the zombified ants were ‘taken’ to this perfect, fungal environment.
Other Not-So-Fun Guys
The actions of Ophiocordyceps unilateralis described here are not unique. There are three other identified fungi that take over ants in a similar way. Two of these produce stalks from the ant’s feet and knee joints, as well as from the head. You may be pleased to hear (after this post has undoubtedly ellicted some sympathy for ants) that one of these fungi, the O. camponoti-novogranadensis, lives in an area that is becoming much drier and hotter -an environment that the fungus can’t survive in and that could well mark its demise. Not too much sympathy there, I suspect.
Thanks to Buddy Venturanza for the incredible close-up photo of the ant. The wonder of microscopic nature. Check out his other great photographs here.
And if you just can’t get enough of ants, take a look at these photographs here and marvel at their beauty.