The story of Sorbus in the Isle of Man is a curious one. Rowan, Sorbus aucuparia, seems to be common and indigenous and there are a number of garden escape species. For a while it was thought that a tree referable to Sorbus admonitor, or Sorbus devoniensis (both Devon specialities) grew there, but I think this is now regarded as an example of Sorbus croceocarpa, one of the aliens.
The wild service, Sorbus torminalis, has not been recorded from the Isle of Man, although it does have a local Manx name
There is an entry for the wild service in the Manx Wiki: http://gv.wikipedia.org/wiki/Billey_greimmey Of interest if anyone wants to see a sample of the Manx language. The wild service is called 'billey greimmey'. 'Billey' simply means tree, but the word 'greimmey' has these meanings: grasp, seize, grab, clutch, catch, hold, snap, stick, bite, lock in, stitch, snatching, adhere, snatch, jam, attach, stitch up, pin on, nab, gripping, seizing, grip, adhesion, tooth, fishing tackle, adherence (of person), monopolization.
Perhaps 'billey greimmey' is a Manxification of 'griping-fruited' service tree', one of the many English names for the wild service. Or maybe 'the tasty bite tree'. I suspect it is a relatively recent translation from English.