This list has been compiled Keiron Derek Brown on 07/02/16 using the publications below and with guidance from the Natural History Museum to take into account subsequent developments in the taxonomy of UK & Ireland earthworm species occurring in natural environments.
Family ACANTHRODRILIDAE Claus, 1880
Microscolex phosphoreus (Duges, 1837)
Family LUMBRICIDAE Rafinesque-Schmatz, 1815
Allolobophora chlorotica (Savigny, 1826)
Allolobophoridella eiseni (Levinsen, 1884)
Aporrectodea caliginosa ((Savigny, 1826)
Aporrectodea cupulifera (Tetry, 1937)
Aporrectodea icterica (Savigny, 1826)
Aporrectodea limicola (Michaelsen, 1890)
Aporrectodea longa (Ude, 1885)
Aporrectodea nocturna Evans, 1946
Aporrectodea rosea(Savigny 1826)
Dendrobaena attemsi (Michaelsen, 1890)
Dendrobaena hortensis (Michaelsen, 1890)
Dendrobaena octaedra (Savigny, 1826)
Dendrobaena pygmaea (Savigny, 1826)
Dendrobaena veneta (Rosa, 1886)
Dendrodrilus rubidus (Savigny, 1826)
Eisenia fetida (Savigny, 1826)
Eisenia andrei Bouché, 1972
Eiseniella teraedra (Savigny, 1826)
Helodrilus oculatus Hoffmeister, 1845
Kenleenus armadas Blakemore 2012
Lumbricus castaneus (Savigny, 1826)
Lumbricus festivus (Savigny, 1826)
Lumbricus friendi Cognetti, 1904
Lumbricus rubellus Hoffmeister, 1845
Lumbricus terrestris Linnaeus, 1758
Murchieona muldali (Omodeo, 1956)
Octolasion cyaneum (Savigny, 1826)
Octolasion lacteum (Örley, 1881)
Satchellius mammalis (Savigny, 1826)
Family SPARGANOPHILIDAE Michaelsen, 1928
Sparganophilus tamesis Benham,1892
British earthworm species checklist notes
Aporrectodea caliginosa is present as a distinctly different morph: nocturna. This morph is an anecic earthworm. Molecular research has indicated that this morph is a distinct species and yet to be published morphological work has confirmed this. For the purpose of the recording scheme we ask recorders to submit records of the nocturna morph as Aporrectodea nocturna. A. nocturna can be distinguished relatively easily as it is larger than A. caliginosa and has a deep red colour and flattened tail (in life only).
Eisenia andrei is extremely difficult to separate from Eisenia fetida, and possibly only distinguishable through molecular work. Some earthworm taxonomists believe that this E. andrei and E. fetida belong to a single species. For the purpose of the National Earthworm Recording Scheme we accept all Eisenia species records as Eisenia fetida as an aggregate species unless an earthworm taxonomist has determined that the record is of E. andrei.
Aporrectodea cupulifera and Kenleenus arnadus are known from Ireland and not from mainland Britain.
Sparganophilus tamesis may not be currently present in the UK and has only been found in proximity to gardens where it is believed it arrived with imported aquatic plants.
Numerous non-native earthworm species have been recorded in artificial environments across the United Kingdom. Any non-native species found in the UK should be verified by an expert through examination of the preserved voucher specimen. Identification of non-native earthworms is likely to require dissection of the specimen.