Earthworm Field Guides
I have been trying to identify earthworms in North America for a couple years now. I have been using several guides to identify these earthworms and I have stumbled across some others that might apply to other parts of the world. Below I will be posting links to these guides. I hope you find these useful.
Canada / Northern USA:
https://www.naturewatch.ca/wormwatch/
UK (will work for most species in the USA because most are introduced from the UK. This is the main guide I use for identifying earthworms):
https://www.imperial.ac.uk/opal/surveys/soilsurvey/
France (appears to include a lot of niche species, but the taxonomy may be outdated, I have not personally used this guide):
https://www.marinespecies.org/aphia.php?p=taxdetails&id=1068175 (linked under the original description tab)