March 02, 2011
As everyone knows, human zombies are created when an uninfected human is bitten by a member of the brain-craving undead. But what about ant zombies? Yes, that's right: ant zombies.
In the South American rainforest, ants have a mortal enemy: the parasitic fungi in the Ophiocordyceps (also known as Cordyceps) genus. These fungi infect ants and other insects, forcing them to do its fungal bidding. For example, a spore-infected zombie ant will climb to a perfectly selected spot in the canopy where it will die. At this point a fungus stalk blooms out of the ant's head; once fully grown the fungus will burst open spreading spores over the area and infecting other ants. Each zombie-inducing fungus species is specifically linked to one ant or other insect species.
A paper in the open-access journal PLoS ONE describes four new species of this fungus from the Atlantic Forest in Brazil, laying the groundwork for studying the zombie relationship in a degraded habitat. Each of the new fungi species, from the Ophiocordyceps genus, were attached to a different species of carpenter ant.
The Atlantic Forestt, running largely along the coast of Brazil, is one of the world's most imperiled rainforests with less than 7% of its original extent remaining. While researchers have studied the relationship between the fungi and its hosts in the largely intact Amazon, little is known about how the fungi species copes in fragmented habitat. In this case, the new fungi species were "all collected within a small area of fragmented, remnant forest". Researchers hope the new fungi species, and their victims, will shed light on how fragmentation impacts them.