A fascinating new discovery in Ireland has revealed the presence of a novel fungus that turns its spider hosts into “zombies.”
The fungus, named Gibellula attenboroughii in honour of Sir David Attenborough, was found in several cave systems across the island, including the Whitefathers’ Caves on the Fermanagh/Cavan border.
The fungus was first identified in County Down during the filming of BBC’s Winterwatch in 2021. It affects spiders by altering their behaviour, causing them to leave their sheltered webs or lairs and move to an exposed position on cave walls or rock surfaces, where they eventually die.
This dramatic behaviour is triggered by the fungus manipulating the spider’s dopamine levels, a chemical in the brain typically associated with feelings of pleasure and well-being.
The fungus uses dopamine to alter the spider’s instincts, prioritising the spread of fungal spores over the spider’s survival.
The behaviour exhibited by the infected spiders mirrors that of ants infected by fungi of the Ophiocordyceps genus, which has been widely studied in the Atlantic rainforest of Brazil.
The discovery of these “zombie ants” has inspired popular culture, including zombie-themed books and the hit video game The Last of Us, which depicts a post-apocalyptic world ravaged by humans turned into zombies due to fungal infections.
The game was later adapted into a successful TV series starring Pedro Pascal and Bella Ramsey.
A team of scientists led by Dr. Harry Evans from the Centre for Agriculture and Biosciences International (CABI) first discovered the fungus on a spider in the gunpowder store at Castle Espie in County Down.
They later enlisted the help of a speleologist, or cave explorer, to further investigate the fungus and its effects on spider populations in cave environments.
The team found that the fungus was native to Ireland and appeared to be specific to indigenous cave-dwelling spider species.
The fungus, which thrives in man-made environments such as tunnels, culverts, and cellars, was found on two spider species: Metellina merianae and Meta menardi. Both are orb-weaving spiders that favour dark, damp cave habitats. These spiders are known for their reclusive nature and their preference for secluded, cool environments.
Dr. Evans and his team’s groundbreaking work on this fungus was published in the journal Fungal Systematics and Evolution.
However, he emphasised that further research is needed to fully understand the mechanisms behind how the fungus successfully infects and controls its spider hosts.
The discovery of Gibellula attenboroughii adds to the growing body of knowledge surrounding fungi that manipulate their hosts in extraordinary ways.
Just as the Ophiocordyceps fungus has captivated scientists and the public, this new fungus in the UK is a reminder of the incredible, often unsettling, ways in which nature operates.
