Insect Mind Control: The Fungus that Turn Ants into Zombies

A close up of a dead ant with the zombifying fungus growing from its head.All images courtesy Dr. David Hughes

Zombie fungi have always been considered among the most disturbing of organisms. Seen as specimens preserved in scientists' labs, for many centuries these fungi have been known to infect a wide range of arthropod hosts. Today they are again gaining fame and are all over the news. A group of four mind-controlling fungi has been discovered in the Brazilian rainforest. Ants beware!

Photo: courtesy Dr. David HughesThe early stages when just after the fungus kills the ant are typified by profuse growth as fungi inside the ant erupt out through the cuticle.

Named Ophiocordyceps camponoti-balzani, these fungi infect ants, then slowly emerge out of their heads, resulting in the death of their innocent hosts. According to research published in the online journal PLoS ONE, these newly found fungus species also have the power to control an ant’s mind and manipulate their behaviour. This act of 'brainwashing' parasitism leads ants away from their colonies to end up on a leaf, an ideal reproductive site for the fungus.

Photo: courtesy Dr. David HughesA dead ant with the fungus growing from the head and covering the body.

A group of researchers, Harry Evans, Simon Elliot, and David Hughes, found out that the fungus is actually four distinct species, all living in Brazil’s Atlantic rainforest. This rainforest is a well-known biodiversity hotspot. "It is tempting to speculate that each species of fungus has its own ant species that it is best adapted to attack," Hughes said.

Photo: courtesy Dr. David HughesOne of the newly described species growing from a dead ant whose body is silhouetted against the leaf it bit before dying.

These four newly-found fungi belong to the genus Ophiocordyceps. Evidence suggests that the parasitic fungi have been infecting these ‘zombie ants' – actually carpenter ants – for about 48 million years.

The fungi, which are helping to deal with the global problem of ‘ant infestation’, can only survive in a place with a certain level of humidity, but climate change is actually destroying their habitat. "We're worried we'll see the extinction of a species we've only just managed to describe." said Hughes.