- Fungal parasites are known to infect ants and control their behaviour
- But until now, it hasn’t been known how the parasites take over their host
- Using 3D scanning, researchers found that the parasite doesn’t infect the brain
- Instead, it infects the muscles, controlling the ant ‘like a puppeteer’
The idea of a fungal parasite that infects ants to turn them into zombies by controling their behaviour may sound like an idea from a science fiction blockbuster.
But the terrifying behaviour happens in reality, and a new study has shed light on the gruesome phenomenon.
Scientists found that the parasite controls the ant through its muscles, without having to infect its brain.
Researchers describe this behaviour as ‘like a puppeteer pulling the strings to make a marionette move.’
Previous studies have shown that the zombie parasite controls the behaviour of carpenter ant workers, making them climb vegetation and bite into the underside of leaves or twigs, where they die.
As the fungus grows in the ant cadaver, it produces a stalk that protrudes from the ant’s head and discharges infectious spores onto the ground below, where they can infect other foraging ants.
But until, the mechanism by which the zombie fungus infected the ant remained unknown.
Now researchers at Penn State University suggest that the zombie ant fungus surrounds and invades muscle fibres throughout the ant’s body, allowing it to control the host’s behaviour.
Ms Maridel Fredericksen, lead author of the study, said: ‘To better understand how such microbial parasites control animal behaviour, we looked at cell-level interactions between the parasite and its carpenter-ant host at a crucial moment in the parasite’s lifecycle — when the manipulated host fixes itself permanently to vegetation by its mandibles.
‘The fungus is known to secrete tissue-specific metabolites and cause changes in host gene expression as well as atrophy in the mandible muscles of its ant host.
Dr David Hughes, senior author of the study, said: ‘We found that a high percentage of the cells in a host were fungal cells.
‘In essence, these manipulated animals were a fungus in ants’ clothing.’
Despite being found in most regions in the ant, the researchers found no fungal cells inside the brain.
Dr Hughes said: ‘Normally in animals, behavior is controlled by the brain sending signals to the muscles, but our results suggest that the parasite is controlling host behavior peripherally.
‘Almost like a puppeteer pulls the strings to make a marionette move, the fungus controls the ant’s muscles to manipulate the host’s legs and mandibles.’
The researchers are unsure why the fungus doesn’t infect the brain.
But Dr Hughes added: ‘We hypothesize that the fungus may be preserving the brain so the host can survive until it performs its final biting behavior – that critical moment for fungal reproduction.
‘But we need to conduct additional research to determine the brain’s role and how much control the fungus exercises over it.’
Read more:
puppeteer bábfigura
fungus gomba
fungal parasite gomba parazita
take over átveszi az irányítást
infect megfertőz
turn into átváltoztat
string kötél
carpenter dolgozó hangya
cadaver hulla
stalk szár
forage gyűjtöget
invade behatol
fibre rost
mandible állkapocs
