By Megan Gannon
A fungus that turns worker ants into zombie henchmen has a surprisingly clever strategy to recruit new hosts.
The parasite doesn’t attack the nest directly. Rather, the fungus leads ants to their deaths along the outskirts of the colony, creating a “sniper’s alley” where the corpses can discreetly spread deadly fungal spores, new research shows.
The parasitic fungus in question,Ophiocordyceps camponoti-rufipedis, is named for the species of carpenter ant that it inhabits, Camponotus rufipes. Under the influence of the fungus, a zombie carpenter ant is led away from its home and forced to climb plants in the understory of the rainforest canopy. After the ant latches onto the underside of a leaf and dies, the fungus sprouts a long stalk from the ant’s cadaver with spores that rain down on the forest floor and infect new ants from the colony that are out on foraging trips.
It’s easier for the fungus to attack outside the colony, because ants are social animals and band together to limit the spread of a disease. In the new study, published yesterday (Aug. 18) in the journal PLOS ONE, scientists working at a research station in Brazil put infected ant corpses inside of several nests. They found that the fungus stalk was not able to grow properly on any of the ant corpses. What’s more, healthy ants removed most of corpses from the nests after several days.