Riolus subviolaceus
- kingdom: Animalia
- phylum: Arthropoda
- class: Insecta
- order: Coleoptera
- family: Elmidae
- genus: Riolus
- species: Riolus subviolaceus
- Gießhübl
- Hainfeld
- Hinterbrühl
- Kirchberg an der Pielach
- Lunz am See
Lower Austria- Gösting
Styria- Garsten
- Grünburg
- Sankt Ulrich bei Steyr
- Steyr
- Waldneukirchen
Upper Austria- Kennelbach
Vorarlberg
Austria- Dolní Dobrouč
Pardubický
Czech Republic- France
- Aachen
- Aldenhoven
- Bad Münstereifel
- Brakel
- Dörentrup
- Euskirchen
- Halle
- Höxter
- Kall
- Marsberg
- Neu-Pattern
- Niedermerz
- Nieheim
- Warburg
- Zülpich
North Rhine-Westphalia
Germany- Bolzano
Trentino-Alto Adige
Italy- Beaufort
02
Luxembourg- Bela Palanka
Central Serbia
Serbia- Ashbourne
- Bakewell
- Bishopstoke
- Bishopstrow
- Bourton on the Water
- Brimscombe
- Chalford
- Chesham
- Chilton Foliat
- Codicote
- Colden Common
- Compton
- Corsenside
- Creswell
- Cromford
- Eastleigh
- Fairford
- Farnborough
- Gainsborough
- Hemel Hempstead
- Hungerford
- Hythe
- Langham
- Little Chalfont
- Little Eaton
- Matlock
- Mayfield
- Mildenhall
- Much Hadham
- Newbury
- Rickmansworth
- Spilsby
- Swanmore
- Tuxford
- Welford
- Whitwell
- Wickham
- Winterbourne
England- Dumfries
- Greenock
- Locharbriggs
- Stevenston
Scotland
United Kingdom