Ophiocordyceps unilateralis, also known as cordyceps, is a type of fungus that infects insects and takes over their nervous systems. The method with which they take control of nervous systems is still a mystery to science. However, the repercussions of such an infection are all too clear.

Carpenter Ants, for example, live in the canopy of the tropical rainforest. They frequently forage for food on the forest floor. Unfortunately, this is where the cordyceps fungus proliferates. A new study shows that the fungus prefers to grow on “the undersides of leaves sprouting from the northwest side of plants that grow on the forest floor” This places it in an ideal position to grow and release its spores to infect ants. Here’s how the fungus gets there in the first place.

When an ant is infected by cordyceps, it undergoes a series of behavioural changes. The fungus forces the ant to climb down from the canopy to the low leaves where the cordyceps prefers to grow. Just before dying, the ant will use its mandibles to bite down on the leaf to secure itself.

After the zombie ant dies, the fungus digests the insides of the ant to get nutrition for growth. It’s interesting to note that the cordyceps avoids digesting the muscles controlling the ant’s mandibles. These muscles are the ones that keep the ant attached to the surface. The outer husk of the ant is also left unharmed. The cordyceps uses this as a physical armor to protect against microbes and other fungi.

The fruiting body of the cordyceps will then erupt from the ants head, slowly growing longer until it matures, after which it will release the spores, which seek new hosts. Any ant in the vicinity of this event risks infection.

A single ant infection is a threat to the whole colony. As such, ant colonies go out of their way to avoid an epidemic. Worker ants will often carry an infected ant far away from where the colony forages to prevent the spread of the fungus. The fact that Carpenter Ants live in the canopy of the rainforest may be a strategy to escape the infection.

Cordyceps does not exclusively target Carpenter Ants. There are many different types of Cordyceps fungi that can infect many different insects, including moths, grasshoppers and many more.

More info: http://bit.ly/fwePdx

A video of Sir David Attenborough narrating the infection process: http://bit.ly/T36QCF

Image Source: http://bit.ly/10Lm2u6

Thanks Riff. You our nature B.C. now?

roughbarked said:

Thanks Riff. You our nature B.C. now?

I don’t think I can supply you his pithy quotes. I posted this for interest and because it includes an unknown bio-mechanism.

Riff-in-Thyme said:

roughbarked said:

Thanks Riff. You our nature B.C. now?

I don’t think I can supply you his pithy quotes. I posted this for interest and because it includes an unknown bio-mechanism.

:) now now.. I was only joshing.

Is a type of fungus that infects insects and takes over their nervous systems. The method with which they take control of nervous systems is still a mystery to science. However, the repercussions of such an infection are all too clear.

OK now they don’t know that you can make an ant mechanically grab on with its mandibles then tear the head off.. keep doing it and stitch a wound this way. I really doubt there is much unknown mystery.

roughbarked said:

OK now they don’t know that you can make an ant mechanically grab on with its mandibles then tear the head off.. keep doing it and stitch a wound this way. I really doubt there is much unknown mystery.

It isn’t that bit they are questioning but this,,,

When an ant is infected by cordyceps, it undergoes a series of behavioural changes. The fungus forces the ant to climb down from the canopy to the low leaves where the cordyceps prefers to grow. Just before dying, the ant will use its mandibles to bite down on the leaf to secure itself.

roughbarked said:

Is a type of fungus that infects insects and takes over their nervous systems. The method with which they take control of nervous systems is still a mystery to science. However, the repercussions of such an infection are all too clear.

OK now they don’t know that you can make an ant mechanically grab on with its mandibles then tear the head off.. keep doing it and stitch a wound this way. I really doubt there is much unknown mystery.

Didn’t know that, but it’s on the internet, so it must be true:

http://www.omg-facts.com/Celebs/Ants-Can-Be-Used-As-Stitches/22621

(Also a link to an AMA journal article from 1925 on Wikipedia).

But isn’t the question how a fungus manages to change an ant’s behaviour in this way? That certainly isn’t obvious to me.

The Rev Dodgson said:

roughbarked said:

Is a type of fungus that infects insects and takes over their nervous systems. The method with which they take control of nervous systems is still a mystery to science. However, the repercussions of such an infection are all too clear.

OK now they don’t know that you can make an ant mechanically grab on with its mandibles then tear the head off.. keep doing it and stitch a wound this way. I really doubt there is much unknown mystery.

Didn’t know that, but it’s on the internet, so it must be true:

http://www.omg-facts.com/Celebs/Ants-Can-Be-Used-As-Stitches/22621

(Also a link to an AMA journal article from 1925 on Wikipedia).

But isn’t the question how a fungus manages to change an ant’s behaviour in this way? That certainly isn’t obvious to me.

It would be easy enough to start digesting the motor mechanisms that unlock the mandibles as naturally they stay locked as a defense mechanism.

It may also be a part of the ants defense mechanism to try to move away from the rest of the colony. Cannot actually prove that the fungi controls the ant until the method is found. I suggest that this may be as much a happy accident as anything else since the amour of the exoskeleton has been mentioned in the article. There can only be a few chinks in the armour and these may well be exact starting points to start digesting certain nerves.

roughbarked said:

It would be easy enough to start digesting the motor mechanisms that unlock the mandibles as naturally they stay locked as a defense mechanism.

It may also be a part of the ants defense mechanism to try to move away from the rest of the colony. Cannot actually prove that the fungi controls the ant until the method is found. I suggest that this may be as much a happy accident as anything else since the amour of the exoskeleton has been mentioned in the article. There can only be a few chinks in the armour and these may well be exact starting points to start digesting certain nerves.

All reasonable hypotheses, but I don’t think we’ve arrived at theory status yet :)

The Rev Dodgson said:

roughbarked said:

It would be easy enough to start digesting the motor mechanisms that unlock the mandibles as naturally they stay locked as a defense mechanism.

It may also be a part of the ants defense mechanism to try to move away from the rest of the colony. Cannot actually prove that the fungi controls the ant until the method is found. I suggest that this may be as much a happy accident as anything else since the amour of the exoskeleton has been mentioned in the article. There can only be a few chinks in the armour and these may well be exact starting points to start digesting certain nerves.

All reasonable hypotheses, but I don’t think we’ve arrived at theory status yet :)

The bull ant famously appears in the philosopher Arthur Schopenhauer’s major work, The World as Will and Representation, as a paradigmatic example of strife and constant destruction endemic to the “will to live”.
“But the bulldog-ant of Australia affords us the most extraordinary example of this kind; for if it is cut in two, a battle begins between the head and the tail. The head seizes the tail in its teeth, and the tail defends itself bravely by stinging the head: the battle may last for half an hour, until they die or are dragged away by other ants. This contest takes place every time the experiment is tried.”

There is another example which I cannot recall all the details off the top of my head and would need to search the posts made by members here for it has been mentioned amongst us that there is an organism which makes ants carry it about by morphing itself to appear like a normal part of the ant nursery. ie: it mimics the part of the developing ant larva that is used as the ‘handle’ to carry the larva to new food and lodgings within the ant colony.

So, why would the fungi bother if there was a better mechanism?

Obviously the researchers are saying that this is because the fungi has a part of the canopy that suits its reproduction and that the ants have elected to move their colony as far away from that region as possible.

roughbarked said:

The Rev Dodgson said:

roughbarked said:

It would be easy enough to start digesting the motor mechanisms that unlock the mandibles as naturally they stay locked as a defense mechanism.

It may also be a part of the ants defense mechanism to try to move away from the rest of the colony. Cannot actually prove that the fungi controls the ant until the method is found. I suggest that this may be as much a happy accident as anything else since the amour of the exoskeleton has been mentioned in the article. There can only be a few chinks in the armour and these may well be exact starting points to start digesting certain nerves.

All reasonable hypotheses, but I don’t think we’ve arrived at theory status yet :)

The bull ant famously appears in the philosopher Arthur Schopenhauer’s major work, The World as Will and Representation, as a paradigmatic example of strife and constant destruction endemic to the “will to live”.
“But the bulldog-ant of Australia affords us the most extraordinary example of this kind; for if it is cut in two, a battle begins between the head and the tail. The head seizes the tail in its teeth, and the tail defends itself bravely by stinging the head: the battle may last for half an hour, until they die or are dragged away by other ants. This contest takes place every time the experiment is tried.”

The ant heap also appears as an analogy for the human brain in Hofstadter’s “Gödel Escher Bach”.

The Rev Dodgson said:

roughbarked said:

The Rev Dodgson said:

All reasonable hypotheses, but I don’t think we’ve arrived at theory status yet :)

The bull ant famously appears in the philosopher Arthur Schopenhauer’s major work, The World as Will and Representation, as a paradigmatic example of strife and constant destruction endemic to the “will to live”.
“But the bulldog-ant of Australia affords us the most extraordinary example of this kind; for if it is cut in two, a battle begins between the head and the tail. The head seizes the tail in its teeth, and the tail defends itself bravely by stinging the head: the battle may last for half an hour, until they die or are dragged away by other ants. This contest takes place every time the experiment is tried.”

The ant heap also appears as an analogy for the human brain in Hofstadter’s “Gödel Escher Bach”.

Then E. O. Wilson may have a better grasp of the situation?

roughbarked said:

Then E. O. Wilson may have a better grasp of the situation?

Presumably he knows more about ants, whether he is better placed to make analogies about human brain mechanisms, I doubt (but I know nothing of his work, so I could be wrong).

The Rev Dodgson said:

roughbarked said:

Then E. O. Wilson may have a better grasp of the situation?

Presumably he knows more about ants, whether he is better placed to make analogies about human brain mechanisms, I doubt (but I know nothing of his work, so I could be wrong).

http://cobberwebs.com/scienceForums/viewtopic.php?f=2&t=41

roughbarked said:

http://cobberwebs.com/scienceForums/viewtopic.php?f=2&t=41

Looks like an interesting discussion, I’ll try and have a proper look when I have time.

With regard to the ant-heap analogy, alternate chapters of Escher Gödel Bach were very much concerned with making advanced mathematical ideas accessible to people without a mathematical background, so it’s not at all inconsistent with what E.O.W. seems to be saying (from my very quick scan of it).

The Rev Dodgson said:

roughbarked said:

http://cobberwebs.com/scienceForums/viewtopic.php?f=2&t=41

Looks like an interesting discussion, I’ll try and have a proper look when I have time.

With regard to the ant-heap analogy, alternate chapters of Escher Gödel Bach were very much concerned with making advanced mathematical ideas accessible to people without a mathematical background, so it’s not at all inconsistent with what E.O.W. seems to be saying (from my very quick scan of it).

:)

Hmm. Interesting.

There are thousands of cordyceps fungi species each with different insect host.

The fungal spores enter the ant via its spiracles.

“The zombie-ant fungus is not the end of the parasitizing line. It meets its own death at the work of yet another parasite. A secondary fungus, a hyperparasite, can cover the original fungus and its stalk, preventing the fungus from ejecting its spores. The second-level parasite seems to sterilize the spores and these hyperparasites aren’t growing on anything else but the specific parasitizing fungi.

This could explain why the zombie-ant fungus has been so successful over the long term since it could severely damage an ant colony. The presence of a hyperparasite could curb infection rates and keep it in check, creating a sort of equilibrium, keeping it from completely destroying ant colonies.”

We have Australian vegetable caterpillars/Cordyceps. Some pictures:

http://www.elfram.com/fungi/fungipics_e.html

So what’s this one eating?

http://www.elfram.com/fungi/fungipics_e.html

————————————-

Nice. Didn’t we have a “Bill L” and also an “elfram” on SSSF, many years ago? The name “Bill Leithhead” seems familiar, too.

Michael V said:

http://www.elfram.com/fungi/fungipics_e.html

————————————-

Nice. Didn’t we have a “Bill L” and also an “elfram” on SSSF, many years ago? The name “Bill Leithhead” seems familiar, too.

One and the same, the lot of ‘em.

:)

Glad I am not entirely mad, then.

:)