New species of Ant-killing fungi

A Camponotus femoratus carcass sprouts an Ophiocordyceps stalk (Ecuador)

This week the biodiversity news is abuzz with tales of new Zombie-Ant Fungi. The sensationalized name aside, these are common rain forest fungi that infect an ant and convince it to walk to an area of optimal fungal growth conditions before killing it and consuming the carcass. It’s a classic case of parasites manipulating the behavior of the host for their own benefit.

The taxonomic story is simple. Up until now, every Ophiocordyceps attacking Camponotus ants was given the catch-all label O. unilateralis. Why? Well, the number of fungus taxonomists is eclipsed by the massive diversity of fungi, and no one had examined these organisms- especially the living organisms- in any detail. In the context of brain-numbing tropical diversity, it was simply easier to lump everything under one published name.

So now Harry Evans, Simon Elliot, and David Hughes have taken a first whack at the problem. They published a short paper in PLoS One noting that different species of Camponotus ants collected in a single patch of Brazilian forest bear fungi with distinct differences in the structure of their fruiting bodies. None of these matched the ant originally bearing the O. unilateralis epitaph. Zing! Four new species.

Based on the sheer diversity of Camponotus (1000+ species worldwide) and the apparent host-specificity of the new fungi, I’d be willing to bet that “Ophiocordyceps unilateralis” will eventually yield dozens- if not hundreds– of novel species. These discoveries will be made not because the fungi are rare or difficult to recognize but for far a far simpler reason. No one has taken the time to look at them before.

Incidentally, I’ve illustrated this post with Ophiocordyceps attacking Camponotus femoratus in Amazonian Ecuador. If Evans et al is any indication, this is also an undescribed species.

Evans HC, Elliot SL, Hughes DP, 2011 Hidden Diversity Behind the Zombie-Ant Fungus Ophiocordyceps unilateralis: Four New Species Described from Carpenter Ants in Minas Gerais, Brazil. PLoS ONE 6(3): e17024. doi:10.1371/journal.pone.0017024

13 thoughts on “New species of Ant-killing fungi”

  1. An addendum, if I were in charge of the nomenclature I wouldn’t have named the fungi after the ant species they attack.

    First, neotropical Camponotus are rather a mess, so the likelihood that at least one of Evans et al’s ants (I’m looking at you, C. novogranadensis & C. balzani) will change names at the first taxonomic revision is high.

    Second, these descriptions are based on limited material from a single location. It may turn out that these same fungi attack different Camponotus in different locations. If that’s the case, then fungal names tied to ant names may only serve to confuse things as knowledge of the group grows.

  2. I’m stealing these pictures of rotting ants to promote my Portobello mushroom farm. I’ll let you know how it goes 😀

  3. First: I would like to say how much I enjoyed Warren’s post — probably far more than you did?!

    Second: as I have a personal bias towards ‘splitting’, I am glad that it seems to be on the rise again. I have never been fond of ‘lumping’. I don’t know if that terminology extends beyond the ‘bird’ world {I’ll bet it does!} but it seems to me that ‘nicer’ and ‘finer’ distinctions * are more helpful.


    *For use of older definitions of ‘nicer’ and ‘finer’ please see any good dictionary.

    1. We lump and split in the insect world as well. My publication record is one of lumping, as that’s the preferable strategy in data-poor environments like tropical myrmecology. Splitting requires a lot of high-quality data for it to be done correctly- if you’ve got it you may as well split. Otherwise splitting tends to reflect sampling error.

  4. Same thing with the ant associated mites- lots are species specific, each ant species has many associated mites, but only a few people have bothered to look at them in detail.

    1. If I were the fungus, I’d sneak into the brain and do some rewiring, either by systematically destroying brain cells, or pumping part of it full of dopamine (or what have you) to get the ant to want to go where the fungus needed.

      But I, being a human, have no idea how to do that. That’s some clever fungus.

      1. Or maybe the fungus have a symbiotic virus! Which infects brain cells, changes gene expression, hijacking the ant’s mind!

  5. I’ve already heard of Cordyceps. Now I’m hearing about Ophiocordyceps which seems to do exactly the same thing yet apparently isn’t particularly closely related. Confused.

    1. It’s the same fungus. The name Cordyceps applied to an enormous, unwieldy genus and was broken up to better reflect evolutionary relationships.

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