Saving the small things that run the planet
The Scarce Yellow Sally (Isogenus nubecula), also known as the Rare Medium Stonefly, is a Critically Endangered native stonefly which is currently only known along parts of the River Dee as it flows through Wrexham County, Wales. (View this page in Welsh)
It’s one of five species of Perlodidae, a stonefly family known from the UK, and is typically found in and around large stony lowland rivers.
Stoneflies have a key role in the life of rivers. Like all invertebrates, they are essential in the food web of their habitat for wildlife such as fish and birds. The Scarce Yellow Sally is no exception, its larvae providing food for the likes of Salmon, Sewin, Grayling and other fish native to the Dee. As adults on the wing, they are a food source to nesting birds, like Sand Martins, and newly hatched songbird chicks.
The Scarce Yellow Sally is also very sensitive to pollution, which means that they can provide invaluable information about the health of rivers. Sadly, pollution is the likely driver behind the species decline.
Why are we doing this survey?
The Scarce Yellow Sally was thought to be extinct in Britain until a small population was found on the River Dee in Wales in 2017. We are keen to understand whether the Scarce Yellow Sally is found in other rivers, especially in and around Wales where it is currently recorded. Due to its mostly hidden lifecycle, recording stoneflies can be difficult. They spend much of their early life underwater, undergoing moults as a larva. However, as adults they leave the water and tend to frequent sunny surfaces and vegetation – that’s where you come in!
What can you do to help?
From April to June, we are asking the public to help us locate, photograph and report any sightings of stoneflies along rivers in Wales. If you live outside of this area but think you may have found a Scarce Yellow Sally, please record your sighting via the form below as well.
If you have any questions, please contact Scarce Yellow Sally Conservation Officer, Sarah Hawkes, at [email protected].
The Scarce Yellow Sally Project is a Buglife partnership project with Natur am Byth! (Nature for All!). The project aims to better understand the current status of the Scarce Yellow Sally Stonefly (Isogenus nubecula) in the Welsh River Dee and engage members of the public on the importance of this stonefly.
Help us to stop the extinction of invertebrate species
Engage with our work
Stay up to date with our work and help spread the word by following us on our socials and signing up to our monthly BugBytes email newsletter.
Donate to support us
Every contribution helps us to save the small things that run the planet by restoring vital habitats and rebuilding strong invertebrate populations in the UK.
Make a donationBecome a member
Join a community of invertebrate champions and access exclusive member benefits from just £3 a month, all whilst supporting our vital conservation work.
Join us