Historical Somerset Plebejus argus.

[nomad]

Hi all. Can anybody supply me with information on the history of the Silver-studded Blue- Plebejus argus in Somerset. Although this species is now extinct in that county, there seems to be a few atlas records of former distribution . In the J.C. & C.W. Dale collection at Oxford there seems to be a long forgotten race with very blue females from the limestone of Langport in Somerset. This locality once held a colony of the Large Blue - Maculinea arion. Any help would be appreciated. Peter.

[Pete Eeles]

Hi all. Can anybody supply me with information on the history of the Silver-studded Blue- Plebejus argus in Somerset. Although this species is now extinct in that county, there seems to be a few atlas records of former distribution . In the J.C. & C.W. Dale collection at Oxford there seems to be a long forgotten race with very blue females from the limestone of Langport in Somerset. This locality once held a colony of the Large Blue - Maculinea arion. Any help would be appreciated. Peter.

Hi Peter - an initial search has only turned up Large Blue and disputed Large Copper records. Was this a result of something you've found in literature (if so, do you have a reference?) or your own observations? If the latter, there are certainly races that exhibit large amounts of blue in the female (e.g. Devon / Cornwall) to which no name has been attributed.

Cheers,

- Pete

[Pete Eeles]

Piers posted this a while ago:

IMHO the split of uk Silver Studded Blue into four distinct subspecies is a little optimistic. The traits that are used to identify certain 'subspecies' (for example blue females) are present in almost all colonies to a greater or lesser degree. SSB females are very variable across the UK range, and colonies (for example) on the Cornish dune systems can throw out a remarkable range of variation; from females with greatly enlarged orange lunules on the upper side, to those with none at all, as well as those that are uniformly brown, to those that are almost all blue. This is true across the majority of colonies in Britain.

The butterfly is adaptable too when it comes to the available food plant. In Cornwall (again as an example) there are colonies which use Birds Foot Trefoil as a larval food (such as the dunes colonies) as well as colonies in the abandoned tin mining areas that use exclusively heather. In captivity, however, females from these colonies will happily lay upon which ever food plant is available from the range of plants that the larvae will consume, demonstrating that the butterfly is simply adapting to whichever food plant is available in the area of the colony.

The labelling of the Portland colonies as a separate subspecies is bordering preposterous. Cretaceous (if it could ever be considered to be a subspecies) inhabited the downland of Kent and Essex etc, quite why the Portland colony should be attributed with this moniker is without substantiation. These colonies again throw out a wide range of variation in both sexes and the fact that they are breeding on the chalk is surely not enough to warrant a subspecific split; there is quite simply not enough distinct differences to separate the Portland colonies from those anywhere else. Plenty of other species exhibit considerable variation across their range and breed in geologically diverse areas and yet these species are not (quite rightly) split into subspecies.

Some people have cited the double brooded Cornish colonies as a reason to award these colonies separate subspecific status, however they are merely responding to the local climate. A second subspecies of SSB can be reared in captivity from any SSB colony in the country (with the possible exception of ssp caernensis) therefore this too surely must rule out grounds for a split.

Argus and caernensis are surely the only two subspecies of the Silver Studded Blue in Britain, distinguished by their distinct size differences and flight periods.

It's certainly an interesting topic, and I am convinced that the usual splits are simply regurgitated in each new book/resource with the same list of vague differentiating characteristics without any research being carried out into whether these splits have any real foundation. The species is simply far too variable for criteria such as greater size and brighter blue in the male (for example) to be grounds for recognition as a distinct subspecies.

All the best for now...

Cheers,

- Pete

[nomad]

Hi Peter. Thank you for your help and information on Plebejus Argus. There are specimens in the Dale collection it seems from Langport in Somerset. Please see this image.

E.B. Ford [ 1945] gives a single dot distribution map for Somerset, which seems to relate to the Polden Hills. This seems to be confirmed by the distribution map for this species in the State of butterflies in Britain and Ireland [ 2006] with gives two crosses for the Polden Hills where it occurred between 1970-1982?. One of the authors was Martin Warren. Best Wishes Peter.

[William]

Hi Nomad,

I've read that there is information on the Large Coppers in the Taunton Museum, I've been thinking of visiting there myself. They can be easily contacted and visits arranged to their collections.

Best Wishes,

William

[nomad]

Hi William
Thank you for your response- to my question. It certainly would be a good move to contact the museum, to see if they have specimens or information on Plebejus argus from Somerset. I have tried Somerset records centre and Somerset butterfly conservation, but have had no reply.

Best Wishes Peter.

[Pete Eeles]

Hi Peter - I've had a good look around and can't find anything that mentions Langport Silver-studs ... perhaps there's something in Dale's diaries to confirm the capture and unusual appearance. Or some commentary from anyone researching the diaries themselves! It's interesting that they're placed immediately below a similar set from Manchester, which are a "known quantity". I've no doubt the Langport specimens are genuine since the last specimen also has a data label with "Langport" written on it.

In the same drawer you may have noticed this Alcon Blue ... from "Nr. Bedford" ... although I believe this has been noted before.

Cheers,

- Pete

[Padfield]

Those female silver-studs are amazing. The one second from the bottom I would undoubtedly have taken for idas if I saw it out here!

What's the story on the alcon blue, Pete? That cannot, surely, have been taken in the UK.

Guy

[Pete Eeles]

What's the story on the alcon blue, Pete? That cannot, surely, have been taken in the UK.

As far as I know, it was among a collection of Large Blues which were all taken in the UK. I also recall there being something in his diaries confirming that he'd taken it near Bedford, but Mark C. will know more than I ... Mark?

Cheers,

- Pete

[Padfield]

What's the story on the alcon blue, Pete? That cannot, surely, have been taken in the UK.

As far as I know, it was among a collection of Large Blues which were all taken in the UK. I also recall there being something in his diaries confirming that he'd taken it near Bedford, but Mark C. will know more than I ... Mark?

Cheers,

- Pete

But we haven't got a species page for it ...

Guy

[Pete Eeles]

But we haven't got a species page for it ...

Because it's not on the British list ... don't ask me why!

Cheers,

- Pete

[nomad]

Hi, those Langport Plebejus argus females do seem to have extensive blue scaling- just lovely and that locality was on Limestone. I thought the single Bedford Large Blue in the Dale collection was a variety of Maculinea arion that Dr Abbot took at Bedford from the colony that he discovered in Mouse's pasture near Bromham, that Dale visited in 1819, not a true Maculinea alcon. Even James Walker of Oxford who reviewed the Dale collection in the Entomologist 1907-1909 took it for M. arion. Are you certain that it is alcon. I am very surprised. J.C. Dale would have ridden his horse to Langport from Glanville's Wootton, a long way, but he did so when he visited Lulworth or Portland.

Best Wishes Peter.

[Padfield]

Very interesting. Sorry to digress from your original topic, Peter!

In answer to your question, no, I can't be sure just from a picture this is alcon rather than a weird aberration of arion, but all visible features point to alcon. It even seems to show the lack of green scaling at the bases of the wings, characteristic of the lowland supspecies, as opposed to the mountain version, rebeli, I see in Switzerland. I think I'm right in saying those specimens date from before the discovery of the ant relationship, so no one could have bred and released it. AND the lowland subspecies of alcon flies (or flew) in northern France and Belgium, so a stray is just possible ...

Guy

[nomad]

Hi Guy. Many thanks, not quite sure of the point that no one was releasing specimens for others to find, even at that early date. George Plastead was such rogue, known to do so at this period. When Dale bought the Abbot collection in 1817, he was astonished to find two exotic skippers said to be taken in Clapham Park Woods where a few years earlier Abbot has found Caterocephalus palaemon, a new British species. He also took a Scarce Swallowtail in 1803 and Queen of Spain and a Bath White in a nearby wood. So someone was either carefully releasing specimens for Abbot to find or he himself was up to tricks. What better result for a dealer to have his butterflies captured by a eminent entomologist who had already discovered a new British butterfly, so he could sell further genuine examples. G. Plastead is known to have provided the Dale Woodside Epping Purple-edged Coppers!

Best Wishes Peter.

[Padfield]

Hi Guy. Many thanks, not quite sure of the point that no one was releasing specimens for others to find, even at that early date.

My point was that before Frohawk made his discoveries, no one could breed alcon blues for release - they would all have died in the third instar, pathetically waiting for an ant to adopt them. If one of your rogues was releasing them they would have to be captured on the continent and imported live. Maybe that's what they did. Real rogues, as you say!

Guy

[Mark Colvin]

The alcon is listed in Dale, C. W., 1890. The History of our British Butterflies (page 60) as follows:

Var. b. (Alcon, Steph.) is of a brownish ash colour on the underside, and has the spots rather indistinct. Stephens records it as being in the collection of Mr. Haworth, and that it was captured in Buckinghamshire, by Mr. Jones, known by his paper on the neuration of the wings of the Linnaean Papilions. After Mr. Haworth's death, it was bought at the sale of his effects, by Mr. Dale. Other examples exist in various other collections.

It is under the heading of Polyommatus arion, the Large Blue and was apparently deemed a variation as opposed to a separate species.

Of course whether or not it is a genuine British record is another matter ...

[Pete Eeles]

Thanks Mark. And online here:

http://archive.org/stream/historyofourb ... 0/mode/1up

Cheers,

- Pete

[Mark Colvin]

It's also listed on pages 84 and 88 of Stephens, J. F., 1828. Illustrations of British Entomology.

[Pete Eeles]

Page 84: http://www.biodiversitylibrary.org/item ... 6/mode/1up
Page 88: http://www.biodiversitylibrary.org/item ... 0/mode/1up

That specimen wouldn't look out of place on eBay, given some of the dodgy Maculinea specimens that appear there

Cheers,

- Pete

[Padfield]

And doing a parallel search, I found it in Westwood's British Butterflies and their Transformations:

http://books.google.ch/books?id=RIFIAAA ... &q&f=false

Guy