Fungus infects cave spiders and turns them into zombies

In Northern Ireland, a unique fungus named Gibellula attenboroughii has been discovered to infect orb-weaving cave spiders, namely Metellina merianae. Researchers from various institutions, including Kew, published their findings in the journal Fungal Systematics and Evolution, revealing that these infected spiders exhibit behaviors reminiscent of 'zombie ants.' The spiders tend to abandon their webs to die in exposed locations on the ceilings of caves, facilitating the fungus's spore dispersal. This fungus induces significant behavioral changes in the infected spiders by producing metabolites such as dopamine, which influence them to migrate from their typical concealed lairs into exposed areas where they eventually succumb to the infection. As a result, the spider cadavers are positioned in highly visible areas, allowing for optimal air circulation, which aids in the effective release and dispersal of the fungal spores throughout the cave system. The behavior observed in infected spiders aligns with earlier studies that identified similar effects in forest ants infected by cordyceps fungi, which are known for altering host behavior to promote spore dissemination. Infected spiders were scientifically observed moving away from sheltered spaces, exhibiting a curious propensity to expose themselves to potential threats rather than seeking security. This latest study not only sheds light on the intricate interactions between fungi and their hosts but also indicates a broader hidden diversity within the Gibellula genus in the British Isles, suggesting that many more species remain to be discovered. Researchers conclude that understanding the dynamics between these fungi and spider populations is vital for comprehending ecological contributions and evolution within these unique habitats.