Eats, shoots and leaves: the parasitic fungus Ophiocordyceps exits an ant victim (Image: David Hughes)
Parasitic fungi turn animals into willing slaves, with gruesome consequences – but it could pay to get to grips with their powers
AS IT floats through the air, a spore of the fungus Ophiocordyceps camponoti-balzani seems benign. But when it encounters an ant its true nature is revealed. First, it punches its way through the insect’s exoskeleton. Once inside, it begins to grow, consuming just enough of its host’s tissues to leave it weakened but functional. Finally, when the fungus reaches sexual maturity, it releases chemicals into the ant’s brain. Under their influence, the hapless insect makes its way to a popular ant meeting place, climbs a plant and clamps its jaws onto the underside of a leaf, just as the parasite consumes its brain. Days later, elaborate fungal reproductive structures shoot out of the insect’s corpse, spores rain down onto the unsuspecting ants on the forest floor, and the cycle begins again.
Parasites come in all sorts of gruesome guises, from blood-sucking lice to eyeball-eating schistosomids. But there is something particularly disturbing about one that can control minds – and O. camponoti-balzani is by no means the only organism that can (see “More mind-controlling parasites”).
What makes this fungus and its relatives particularly intriguing, though, is that their secrets are starting to be unravelled – a breakthrough that could help create new types of insecticide, open a new front in the fight against insect-borne diseases and perhaps even one day bring novel treatments for human psychological conditions. Finally, we are learning …
