I’ll be honest, I’ve known about cordyceps for some time but for some reason hadn’t quite expected they might be findable in Ireland without being specialised about it. Anytime I idly search for information on them in Ireland I am bombarded with herbal supplement sites, all trying to sell me some in powdered form. I’ve not done a lot of research into those supplements, but I know they’re credited with some excellent benefits, but I have been on the search for them more to see the colour of some of the varieties and to maybe experiment with them as a dye source, depending on how plentiful they might be and if I can cultivate them in some way. I am reasonably sure I saw something in an Asian food store at one point, and will have to follow up on that too.

Cordyceps are utterly fascinating – I first came across them in David Attenborough’s Planet Earth in a section on Bullet ants in the jungle – I remember getting the vague impression that there were thousands of cordyceps varieties, each specialising in one insect kind but continued with the erroneous idea that they were all in the jungle (where apparently 80% of the worlds insect populations all live) for a while after. This is a piece of that Planet Earth https://www.youtube.com/watch?v=XuKjBIBBAL8 – if you like zombie stories/films some of it may be familiar to you. If you dislike insects this is not the video for you, lots of close ups, even if they are being taken over by a fungus *and mind controlled* . If you have any knowledge about fungus and the human body it may also make you pause a little, or even a lot. I will talk about this with people if they’re interested, but I’m not going to go into it here and now, let’s stick to “colourful mushroom does bad things to insects but makes pretty colours!” for now. To describe the video a little – basically ants can get infested with spores of the cordyceps mushroom, a particular species that targets ants, and when other ants realise what is happening they will kick that ant out as far away from the rest of the colony as soon as possible. The infected ant is doomed, the fungus takes over, makes the ant climb to a high spot and hold on to its vantage point, it then dies as it takes several days for a fungal spike to push through the ants head and ripen to a tip of spores that are then released from that high point to rain down on any ants in the area – whole colonies can get wiped out. The video goes on to show the aftermath of many other types of insects that were similarly colonised by spores, each one infected by its own type of cordyceps.

What prompted me to start this post was a book written by Rachael McKenna called Step into Nature – A chronicle of Irish Nature through the year – my version is small and lovely, and I picked it up in Co. Offaly, where I know Rachel has found an enormous amount of wild things and reported them in an app created by The National Biodiversity Data Centre. I I flipped my new book open to January and was surprised to see in the illustration for week one some Scarlet Caterpillarclub cordyceps militaris. The exact one I wanted to try dyeing with, since I know it’s supposed to be cultivatable on rice.

“Scarlet Caterpillarclub, cordyceps militaris, is a parasitic fungus which grows out of buried moth pupae. We were fortunate enough to discover one in the garden, close to the short grass, with its vibrant colour and speckled appearance.” (Rachel Mckenna, Step into Nature, pg20)

The mushroom grows like an orange club ended finger upright from grass, each having burst from the moth pupae. Now while I was mulling over what to actually say to kick start my annual “It’s Spring, look I can write again!” fest, some articles started to appear in papers about cave spiders in County Cavan/Fermanagh (for example this one https://www.irishtimes.com/environment/2025/02/04/fungus-infected-zombie-spiders-found-in-caves-are-unique-to-ireland/ ) and today this video by Garron Noone popping on youtube reminded me I had started this post – https://www.youtube.com/shorts/GEKavPcDr0Q –

So yeah, spiders. I know many people do not like spiders, but I tend to like them, and I definitely feel more sorry for them than I ever would about the ants. That stuff looks like a facehugger orgy on the poor thing. The fungus Gibellula attenboroughii ( a type of Cordycipitaceae) infects the spider, begins to consume it, makes it travel out to the open and go to a point where spore distribution is most useful. The attenboroughii variety is unique to Ireland, but there are many other types of Gibellula fungus infecting spiders in other places, including Scotland as evidenced by this report last year https://theecologist.org/2024/oct/04/last-us-fungus-found-scotland so I’m reasonably sure it’s not that Cordyceps are just lately stepping into new species in a bid for world domination. though if you look around the world some days you might wonder if they’d make a better job of it.

Disclaimer: I have not seen the Last of Us – apparently everyone jumps to it when talking about Cordyceps, and I strongly suspect I do not wish to see it and will continue to avoid seeing it.

I also believe there is some debate on classification of the zombie making cordyceps – that they are more correctly Ophiocordyceps, but I am absolutely not well up on classifications, it alarms me sometimes how I think I know something to find that no, no, I really don’t.

Because I have not found a cordyceps mushroom of my own this post’s featured photo is through creative commons – By Andreas Kunze – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=16244069