{"id":1085,"date":"2026-04-29T16:20:17","date_gmt":"2026-04-29T16:20:17","guid":{"rendered":"https:\/\/flatplanplus.io\/bbc-sciencefocus\/?p=1085"},"modified":"2026-04-29T16:20:17","modified_gmt":"2026-04-29T16:20:17","slug":"a-devastating-fungal-invasion-is-now-sweeping-the-us-and-it-may-be-too-late-to-stop-it","status":"publish","type":"post","link":"https:\/\/flatplanplus.io\/bbc-sciencefocus\/2026\/04\/29\/a-devastating-fungal-invasion-is-now-sweeping-the-us-and-it-may-be-too-late-to-stop-it\/","title":{"rendered":"A devastating ‘fungal invasion’ is now sweeping the US. And it may be too late to stop it"},"content":{"rendered":"\n
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nature<\/p>\n\n\n\n

A devastating ‘fungal invasion’ is now sweeping the US. And it may be too late to stop it<\/h1>\n\n\n\n

They\u2019re tasty, they\u2019re beautiful \u2013 and they\u2019re ripping through delicate ecosystems<\/p>\n\n\n\n

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By tom howarth<\/p>\n\n\n\n

\u2013<\/p>\n<\/div>\n<\/div>\n\n\n\n

\"Golden
Photo credit: Getty<\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n

The golden oyster mushroom is beautiful, delicious and \u2013 if ecologists are right \u2013 one of the more insidious biological invasions currently unfolding in North American forests. <\/p>\n\n\n\n

No one knows exactly when it arrived, or how. Sometime around 2010, best guesses suggest, it began sprouting from dead wood in the forests of the northeastern US. Then it started spreading.<\/p>\n\n\n\n

\u201cThere are areas now where it is almost the only mushroom you see in the woods,\u201d says Michelle Jusino, an assistant professor of forest pathology at the University of Florida. \u201cIt is striking, beautiful \u2013 and horrifying.\u201d <\/p>\n\n\n\n

Everywhere it goes, this fungus is pushing out native species and permanently altering ecosystems. Today, it\u2019s in more than half of US states with no signs of slowing down. <\/p>\n\n\n\n

An invasion begins<\/h2>\n\n\n\n

The golden oyster mushroom (Pleurotus citrinopileatus<\/em>) began its life in the forests of eastern Russia, northern China and Japan, where it has been a popular staple of local cuisine for centuries. <\/p>\n\n\n\n

They were introduced to the US in the early 2000s, as the culinary market for exotic mushrooms began to boom. <\/p>\n\n\n\n

Home mushroom-growing kits, sold online and in garden centres, made golden oysters accessible to anyone. The kits were cheap, simple and wildly popular. But somewhere along the line \u2013 nobody knows exactly where \u2013 the mushroom got out.<\/p>\n\n\n\n

\u201cThe potential source of it could be anywhere,\u201d says Aishwarya Veerabahu, a PhD researcher at the University of Wisconsin-Madison and lead author of a 2025 study<\/a> on the invasion. \u201cMushroom farms have a constant outgoing airflow, releasing millions and billions of spores every minute.\u201d<\/p>\n\n\n\n

Consumers composting used grow kits in their gardens may have done the rest. \u201cIt\u2019s truly a two-pronged point of origin,\u201d Veerabahu says. <\/p>\n\n\n\n

Either way, by the early 2010s, it was loose in the wild. And it had no intention of stopping.<\/p>\n\n\n\n

Golden oyster mushrooms spread by releasing millions of microscopic, white spores from the gills on the underside of their caps when they mature. Video credit: Aishwarya Veerabahu<\/figcaption><\/figure>\n\n\n\n

Veerabahu\u2019s study, published in Current Biology<\/em>, offers the clearest picture yet of the damage being done.<\/p>\n\n\n\n

The team drilled into dead elm trees in forests around Madison, Wisconsin, extracting wood samples and analysing the DNA of every fungus living inside. Some trees hosted golden oyster mushrooms; some did not. <\/p>\n\n\n\n

Trees with golden oyster mushrooms housed only half as many fungal species as those without. In some cases, even fewer. Native species, including the mossy maze polypore and the elm oyster mushroom, were being pushed out entirely.<\/p>\n\n\n\n

Why does this matter? Fungi are not incidental to forest life but foundational to it. They break down dead wood, cycle nutrients back into the soil and form symbiotic networks with plant life. <\/p>\n\n\n\n

Such loss of diversity could have consequences for us humans too. For example, fungi are a common source of life-saving medicines, including penicillin. <\/p>\n\n\n\n

\u201cIf you have a fungus like this pushing out the native biodiversity and potentially causing local extinctions,\u201d Veerabahu says, \u201cwhat does that mean for a medicine that could have been in one of those fungi that we don\u2019t get anymore?\u201d <\/p>\n\n\n\n

\"Golden
According to Jusino, some trees are almost completely covered from the base to the canopy with golden oysters. Photo credit: Aishwarya Veerabahu<\/figcaption><\/figure>\n\n\n\n

And there are deeper structural concerns for the ecosystem. Golden oyster mushrooms are white-rot fungi, meaning they break down wood differently to many native species. <\/p>\n\n\n\n

Jusino warns that a large-scale shift in rot type could alter how carbon moves through forest ecosystems \u2013 potentially pushing more of it into the atmosphere. \u201cGlobal carbon cycles are pretty important,\u201d she adds.<\/p>\n\n\n\n

Officially, the mushroom has been confirmed in at least 25 US states and two Canadian provinces, although Veerabahu says the real number is likely a bit higher now. <\/p>\n\n\n\n

Beyond the US, it has been spotted in the wild in the UK, Germany, Switzerland, Austria, Hungary and Italy. With climate change opening new habitats, the range is only expected to grow. <\/p>\n\n\n\n

\u201cI am watching it march further and further south in the United States now,\u201d Jusino says, \u201cand thinking: how far is it going to go?\u201d<\/p>\n\n\n\n

The genie is out of the bottle<\/h2>\n\n\n\n

The most troubling aspect of this invasion is perhaps that there is no way to reverse it. <\/p>\n\n\n\n

Fungi don\u2019t exist merely as mushrooms. A mushroom is only the visible fruiting body, beneath which lies a vast network of mycelium threading through wood and soil. You can remove what you see but the rest of the organism remains intact. <\/p>\n\n\n\n

\u201cWhen an invasive fungus gets out into the environment, there is no getting it out,\u201d Veerabahu says. \u201cThe only measures you can take are preventative.\u201d<\/p>\n\n\n\n

Some producers have already acted and have stopped selling golden oyster products. But the broader industry has been slower to respond, and researchers are already worried about what fungus species may come next. <\/p>\n\n\n\n

\u201cWe\u2019re really trying to shift and focus on what can be done, not just for golden oyster mushrooms but for other cultivated fungi,\u201d Jusino says. \u201cIt is a massive movement right now; fungi are having this moment, which is exciting, but we also need some boundaries.\u201d <\/p>\n\n\n\n

\"Yellow
It may be too late to stop the spread of golden oyster mushrooms, but steps can be taken to stop other cultivated species from escaping. Photo credit: Aishwarya Veerabahu<\/figcaption><\/figure>\n\n\n\n

The longer-term hope, according to Veerabahu, may lie in developing sporeless strains that can\u2019t escape, and in establishing clear guidelines for growers and consumers alike. <\/p>\n\n\n\n

In the meantime, citizen science is playing a critical role. Much of what researchers know about the mushroom\u2019s range comes from observations posted to iNaturalist, a free website and app where users log wildlife sightings with photographs and location data. <\/p>\n\n\n\n

\u201cIt is actually the most useful thing they could do,\u201d Veerabahu says. If you are walking in woodland and spot a vivid yellow cluster erupting from a dead log, take a photograph, note the location and post it.<\/p>\n\n\n\n

And if you\u2019re confident in your identification, you can do one more thing: eat it.<\/p>\n\n\n\n

Veerabahu still forages golden oysters herself. \u201cI chop them up pretty fine, dry saut\u00e9 them to pull the water out, and then add some oil and garlic and put them in tacos,\u201d she says. \u201cI think it is the best way to eat them.\u201d<\/p>\n\n\n\n

However, foraging for mushrooms is always a fraught endeavour. Yellow oysters closely resemble several other types of mushrooms, including the poisonous Jack-o\u2019-lantern, so make sure you know what you’re doing before taking any home for dinner.<\/p>\n\n\n\n

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by TOM HOWARTH<\/strong><\/em><\/p>\n\n\n\n

Tom is the trends editor for <\/em>BBC Science Focus.<\/p>\n\n\n\n

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Read More:<\/h3>\n\n\n\n