The extinct British Plebejus argus masseyi & cretaceus ssp.

I do find geographical variation in butterflies interesting. Plebejus argus exhibts some of the most interesting and complex geographical variation of the butterflies that are found in Britain.
It does seems that there is a interesting and long forgotton race of Plebejus argus in the Dale collection at Oxford. While looking at a Lycaenidae drawer, I noticed a small series of P. argus with extensive blue on the wings, but even more intriguing was the locality - Langport in Somerset. The limestone ridge at Aller near Langport was also once a locality for Maculinea arion - the Large Blue, but I have never heard P. argus from that locality. Plebejus argus was historically recorded from a number of scattered sites in the north and west of Somerset. Today sadly all these localities have been lost and in Somerset it is now extinct. It was only said to have been plentiful at Bridgewater and Taunton, which are quite near to Langport, but at both localities, the colonies were found on marl clay and not limestone. There are specimens in the Taunton museum from that locality that occured on sandstone marl clay, and I hope to visit later in the year to see how specimens from Taunton differ from those that occured 15km away at Langport on the limestone. The only other British races of P. argus that were found on the calcarous soils in England was the extinct southern chalk downland subspecies cretaceus and the extant population occuring on the limestone of Portland in Dorset. The females specimens from Langport show a much more extensive blue scaling than either of those two races and are quite different from those that occur on heathland. In communication, one butterfly expert, mentions that if he spent a day in any lowland Plebejus argus argus English locality he could produce a few blue females, however he mentions that he could not on the heathlands of Dorset or New Forest where most of the today's extant populations are concentrated. I have experienced of argus colonies in heathlands in other English counties except Norfolk and all of the colonies seem to produce small brown females. At Pree's Heath further north there is a mixture of blue/brown females and there are on the coastal sand dunes of Cornwall . J.C. Dale visited Langport to collect Maculinea arion on the 15th June 1834. At Aller, the historical Langport M. arion site , a low limestone ridge there is currently a reintroduction programme for this species. It was James Dale who first discovered the limestone population of P. argus on Portland and he wrote " there is no heath here", he was used to seeing this species on the Dorset Heathland, the usual lowland habitat. Dale sent his records for Maculinea arion to Edward Newman for use in his ' British Butterflies' [ 1871]] and a John Quckett who discovered the to Langport site for this butterfly , mentioned that the habitat had to abounded in long grass and brambles.  I have read the Maculinea arion became extinct at Langport in the 19th century, but according to another English entomologist, it hung on there till the 1950's! The only locality that Newmen [1869] listed for Plebejus argus in Somerset was at Brockley in the North of that County. I remember seeing the great Edward Newman book in my local reference library as a boy. I was most interested in his old list of county localities, I saw that in Gloucestershire at Sapperton in the Cotswolds there were three large fritilllaries, A. aglaja, A. paphia and A adippe. I went by bus, I caught the first two, but the latter had gone. The entomologist who sent these Cotswold Fritillary records to Newman, also collected M. arion on the same ground where A. aglaja was still flying during my visit a hundred years later. Peter.



The Dale Langport Plebejus argus