Invasion of the ‘Zombie’ Ant
Researchers at Penn State University have discovered a startling fungus among the Tropical Carpenter Ant community. Infection by this new strand of parasitic fungus has been found to dramatically change the behavior of the Carpenter Ant, causing an ant to become zombie-like and die in a spot in which the fungus has optimal reproduction conditions.
Using transmission-electron and light microscopes the research team was able to look inside an infected ant to determine what effects the fungus was having. They found that the fungus fills the ant’s body and head, eventually causing muscle atrophy and forcing muscle fibers to spread apart. It was found that the fungus effects the ant’s central nervous system as well.
Upon observation in the wild, researchers noticed that normal worker ants rarely leave their work trail, whereas ants infected with the fungus or “zombie” ants will walk in a random manner and will be unable to find their way home. Infected ants were also found to suffer from convulsions which cause them to fall from the canopy to the ground and be unable to find their way back up to the canopy again. This creates the perfect conditions for their fungus to thrive at about 9 to 10 inches above the soil where temperatures are cooler.
The strangest finding by the research team was found during solar noon, when the sun is at its highest temperature. The fungus began to control and synchronize individual ant behavior. Infected ants would crawl to the underside of a nearby leaf and bite into its main vein, causing the ants to break their jaws and remain stuck upside down from the leaf even after death. A few days later the fungus will grow through the ant’s head in a icicle like shape and release spores to be picked up by another wandering ant.
Lead researcher David P. Hughes said, “The fungus attacks the ants on two fronts: first by using the ant as a walking food source, and second by damaging muscle and the ant’s central nervous system.” This results in an ant placing itself in the perfect conditions for fungal growth and reproduction. Future research is currently being conducted to determine how this newly found fungus can be used to control pest insects in both homes and farms.
Photo Source: ars.usda.gov