Abax parallelus was added to the British list by K.G. Blair on the basis of a single specimen which “was taken by my brother, Wm. N. Blair, on the island of St. Mary’s, Scilly, in July 1913” (Blair, 1919). The specimen was “placed in the collection of British Coleoptera in the Natural History Museum” by K.G. Blair, and is still there to this day “labelled Scilly July 1913 KG Blair [in pencil in KG Blair’s handwriting]” (Roger Booth, by email, March 2013).
Lindroth (1974) states “this species is known in Britain only from the Scilly Islands (Power coll., Brit. Mus.), probably as a result of occasional introduction.” Luff (2007) states that “A. parallelus (Duftschmid) has been recorded as a casual immigrant in the Isles of Scilly”. Duff (2012a) transferred Abax parallelus from the main British list to the appendix list of non-established introductions, and likewise Duff (2012b) states that “Abax parallelus (Duftschmid) has been recorded as a non-established introduction”.
I had always assumed that Abax parallelus was at one time established on the Isles of Scilly, even if it had already become extinct by the time I got into beetles – otherwise why would Lindroth (1974) include it in his keys if it was only known from a single specimen? That assumption was reinforced by a footnote to Abax parallelus in the June 2005 version of Andrew Duff’s Checklist of Beetles of the British Isles which stated: “Temporary introduction, extinct; 19th-Century records only, Isles of Scilly”.
However, there is no evidence to suggest that Abax parallelus has ever been recorded in Britain apart from the single Scilly specimen, and thus no evidence that it was ever established here as a breeding species. Duff (2012a) was absolutely right to demote it to the list of non-established introductions.
So where did the line about “19th century records” come from? I suspect the answer is in Lindroth’s (1974) reference to the species being present in the Power collection at the Natural History Museum. John Arthur Power lived from 1810 to 1886 and was active as a coleopterist from 1834 to 1881 (Michael Darby’s Biographical Dictionary of British Coleopterists). One might assume (as I did) that any specimen in “the Power collection” must have been added to the collection prior to his death. However, as Roger Booth has kindly explained, from the time that it arrived in London, the J.A. Power collection was such a comprehensive collection, that it was used in the Coleoptera section as THE British beetle collection. Even in the mid 1970s, when Roger first started using the NHM collections, the Power collection was the main collection to use to identify British beetles. As such, when a beetle new to Britain was found, the then obvious place to put it was with the Power collection. Carl Lindroth would have seen the 80 drawers of the Power collection in their 2 cabinets. Material from later British collections was added over the years, including material collected by Joy, Massee, Yerbury, and K.G. Blair himself, and Peter Hammond was continuing to add staphs well into the 1990s.
Abax parallelus is brachypterous and so its occurrence on Scilly is almost certainly the result of human introduction. The alternatives of natural colonisation via ice-age land bridges and/or rafting are so implausible as to be barely worth mentioning.
No doubt Abax parallelus could turn up in Britain again. Its identification has not been covered by Luff (2007) or Duff (2012b) but the species was keyed out by Lindroth (1974) and Blair (1919) also gives identification characters.
I am most grateful to Roger Booth of the Natural History Museum for taking the time to check on the Abax parallelus specimen and outlining the history of the Power collection.
Blair, K.G. (1919). Abax (Pterostichus) parallelus Dufts., a beetle new to Britain. Entomologist’s monthly magazine, 61, 7 – 8. Online here.
Duff, A.G. (2012a). Checklist of beetles of the British Isles. 2012 edition. Iver: Pemberley Books.
Duff, A.G. (2012b). Beetles of Britain and Ireland. Volume 1: Sphaeriusidae to Silphidae. West Runton: A.G. Duff.
Lindroth, C.H. (1974). Coleoptera, Carabidae. Handbooks for the identification of British insects, vol. 4, part 2. London: Royal Entomological Society. Online here.
Luff, M.L. (2007). The Carabidae (ground beetles) of Britain and Ireland. Handbooks for the identification of British insects , volume 4, part 2 (2nd edition). St Albans: Royal Entomological Society.