Isogenus nubecula

{{Short description|Species of stonefly}}

{{Speciesbox

| image =

| genus = Isogenus

| species = nubecula

| authority = Newman, 1833

}}

Isogenus nubecula, also known as scarce yellow sally, is a species of stonefly belonging to the family Perlodidae.{{cite web |title=Isogenus nubecula Newman, 1833 |url=https://www.gbif.org/species/2004508 |website=www.gbif.org |access-date=9 February 2021 }} It is native to Europe.

The insect was thought to be extinct in Britain, having last been recorded in 1995, but a small population was found on the River Dee, Wales in 2017.{{cite journal |last1=Davy-Bowker |first1=John |last2=Hammett |first2=Michael J. |last3=Mauvisseau |first3=Quentin |last4=Sweet |first4=Michael J. |title=Rediscovery of the critically endangered ‘scarce yellow sally stonefly’ Isogenus nubecula in United Kingdom after a 22 year period of absence |journal=Zootaxa |date=13 March 2018 |volume=4394 | issue=2 |doi=10.11646/zootaxa.4394.2.12}} In 2023, the insects were being bred in captivity at Chester Zoo with a view to reintroduction to the wild when water quality has improved.{{cite web | url = https://www.bbc.co.uk/news/science-environment-66531535 | title = Conservation: Lifeline for endangered insect feared extinct | date = 2023-08-22 | website = BBC News Online | access-date = 2023-08-22}}{{cite web |title=Buglife News: Conservationists race to save critically endangered insect found in the River Dee in Wales |url=https://www.buglife.org.uk/news/conservationists-race-to-save-critically-endangered-insect-found-in-the-river-dee-in-wales/ |website=Buglife |access-date=29 August 2023}}

The species is regarded as critically endangered.