Newly discovered fungal species makes zombies of cave spiders on island of Ireland

Dr. Harry Evans, Emeritus Fellow at CAB International, led scientists—including from the Natural History Museum of Denmark and Royal Botanical Gardens Kew—in a study to investigate the identity of a fungus found on a spider during filming of the BBC Winterwatch series in Northern Ireland. The work is published in the journal Fungal Systematics and Evolution.

Based on both morphological and molecular evidence, the fungus was confirmed as a novel species and "named after the broadcaster and natural historian Sir David Attenborough, a pioneer of BBC natural history programs, who—in his role as controller of BBC 2—helped to develop the Natural History Unit; leading, indirectly, to the present nature series during which the new species was first discovered."

Subsequently, the spider host was identified as the orb-weaving cave spider, Metellina merianae (Tetragnathidae: Araneae), and—through the help of a local speleologist—further specimens of the new species, Gibellula attenboroughii, were found in cave systems in both Northern Ireland and the Republic of Ireland, as well as on a related spider, Meta menardi, occupying different ecological niches within the caves.

Like the type specimen, originally located on the ceiling of a gunpowder store, all the infected spiders were positioned on the roof or walls of the caves. These normally reclusive spiders left their lairs or webs and migrated to die in exposed situations, essentially, mirroring the behavior of ants infected by fungi of the genus Ophiocordyceps previously reported from the Atlantic rainforest of Brazil.

Such manipulation of the host in order to favor dispersal of the fungal spores engendered the description of 'zombie-ant fungi' and led to the publication of a number of zombie-fungus themed books, as well as to a popular video game and the television series, The Last of Us. Behavioural-changing metabolites, such as dopamine, have since been identified in cultures of zombie-ant fungi of the genus Ophiocordyceps.

The scientists also used historical herbarium records and literature searches to uncover a hidden diversity within the genus Gibellula in the British Isles, along with evidence of widespread disease epidemics on spiders in Norfolk and Wales. It was concluded that "their role in spider-population dynamics warrants further study, as does the metabolites they produce which enable them to exploit such a highly specific ecological niche."