Cordyceps and Ophicordyceps: the zombie fungi made famous by The Last Of Us

Cordyceps and Ophiocordyceps are the stuff of nightmares – if you’re an insect, or if you’ve played or watched The Last Of Us.

By Megan Shersby

Published: Friday, 03 February 2023 at 12:00 am

What are Cordyceps and Ophiocordyceps?

Both Cordyceps and Ophiocordyceps are fungi genera, which compose of about 750 species. Many of them are parasitic, infecting insects and other arthropods with their spores.

Upon infection, some of the host tissue is replaced by the fungi’s mycelium and results in the fruiting bodies growing out from the host’s body.

The fungi also cause a change in behaviour, in order to maximise its chance to passing onto new hosts.

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A large moth parasitised and killed by Cordyceps fungus in the Ecuadorian Amazon. © Dr Morley Read/Getty
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Cordyceps fungus emerging from an ant. © Reza Saputra/Getty
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Cordyceps militaris growing on a mulberry silkworm pupa. © Kornwipa Ponganan/Getty
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Dead adult Calyptrate fly by a fungus of the genus Ophiocordyceps. © Vini Souza/Getty
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Cordyceps entomorrhiza emerging from body of larva of a longhorn beetle. © Ian Redding/Getty
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A fly parasitized by a Cordyceps fungus in rainforest, in Ma Da forest, Vietnam. © Getty
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Cordyceps fungi emerging from an insect. © Luis Espin/Getty
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Cordyceps militaris fungus growing from a butterfly cocoon. © Getty
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Cordyceps fungus growing from a bullet ant (Paraponera clavata) near Puerto Viejo de Sarapiqui, Costa Rica. © Kevin Wells/Getty
The fungi have found fame in recent years, thanks to The Last Of Us (a video games series first released in 2013 and now adapted into a drama on Sky) and to The Girl With All The Gifts (a novel released in 2014 and adapted into a film).

In both of these, the parasitic fungi adapted to infect humans and resulted in a pandemic of zombie-like people that bite others in order to spread the fungi, and leading to the collapse of human civilisation. In The Last Of Us, the fungi was an unspecified Cordyceps species, whilst in The Girl With All The Gifts it was Ophiocordyceps unilateralis.

O. unilateralis is also known as the zombie-ant fungus as it infects ants in the Camponotini tribe. It was first described by the British naturalist Alfred Russell Wallace in 1859.

Once infected, the ant is controlled by the fungus, which causes it to leave its nest, climb up the stem of a plant and secure itself in place with a death grip – usually about 25cm above the forest floor. Once there, the fruiting bodies grow out of the ant’s head and shower spores down onto the ground below – the aim is infect more ants.