Weird, Wonderful Wildlife #6 – The Cordyceps Fungus

Fans of the popular HBO series, The Last of Us will probably cringe at this subject, but rest assured, the premise of the show is completely bogus for the simple fact that a human body is too warm to incubate a cordyceps fungus. Instead, ophiocordyceps unilateralis has evolved over several millennia to “zombify” specific species of ants, which also renders it incapable of infecting humans. Scientists aren’t entirely certain how Cordyceps takes over its host, but it’s believed the spores are able to penetrate the ant’s exoskeleton. There is an incubation period where the ant will just go about its business in the colony and appear perfectly normal to the other ants (they would kick the infected any out of the colony if it acted sick). Eventually, Cordyceps will compel the ant to leave its nest in favor of the more humid climate the fungus prefers. The ant climbs a plant about ten inches off the ground, sinks its jaw into a leaf and waits for death as the fungus devours it from the inside out; the whole gruesome banquet culminates in the fungus pushing out from the ant’s head to send spores out to create the next generation of these creepy fungi.

To call this a zombifying fungus isn’t entirely accurate – researches at Penn State studied infected ants and observed that there is no fungal infection of the brain. Instead, they concluded that the fungus controls the ants nervous system and its movements, which doesn’t fit the definition of zombification. There are over 200 species of Cordyceps fungi that infect ten different insect orders. One particular species, O. sinensis infects ghost moth larva, erupting from its head the same way it emerges from the ant. This combination is highly prized as an immune booster and aphrodisiac in parts of Asia. Another species has a positive symbiotic relationship with the Japanese cicaida that helps its host process sap. Aren’t you glad you can’t be infected by Cordyceps?

Source: http://www.nationalgeographic.com/animals/article/cordyceps-zombie-fungus-takes-over-ants