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