Species Taxonomy

[Pete Eeles]

After some debate with Felix (Piers), we've decided to adopt "A Checklist of Lepidoptera Recorded from the British Isles" (2000), Bradley & Bradley (other sources I've used in the past are somewhat-inconsistent). The main reason for this is that it is considered (in the British Isles at least) the authority in terms of species classification. The Bradley taxonomy can be found at:

http://www.ukbutterflies.co.uk/taxonomy.php

and now includes all of the rare migrants and introductions too. Some of the more major changes are:

1. Some of the "subtaxa" have switched from being a subspecies to a form.
2. The set of subspecies has also been revised (which affects rare migrants and introductions in the main).
3. The genus of several species has changed.
4. The masseyi form of Silver-studded Blue is considered extinct.
5. All species pages and galleries have been updated accordingly.

Cheers,

- Pete

[Padfield]

Interesting. I prefer this taxonomy to that of Fauna Europaea and think you have made the right move there, Pete (and Felix). I do still hanker after the old, smaller, genera, though . There's no scientific reason for lumping at the generic level, which most modern taxonomy has done - it's more or less arbitrary where you draw the line around a genus, providing it has cladal integrity (which is admittedly harder to determine the smaller the genera, because you need to know that much more about the evolutionary relationships between the species). But in the field it is definitely useful to think of Boloria being distinct from Clossiana (for example) and Melitaea as being distinct from Mellicta. I'm glad you're recognising more blue genera (I hated Polyommatus expanding and eating everything up; and in Switzerland they insist on putting the Everes species in Cupido...).

I'll probably never get used to Ochlodes faunus, but since the species has been split I don't think I have any choice! If I remember correctly, the type specimens were of the Eastern variety.

Guy

[Pete Eeles]

I'll probably never get used to Ochlodes faunus, but since the species has been split I don't think I have any choice! If I remember correctly, the type specimens were of the Eastern variety.

Yes - that's what Bradley indicates.

I'm not 100% comfortable with everything in Bradley - but at least it's a firm stake in the ground that is, at least, consistent with itself! Having "Maculinea arion" back (rather than Glaucopsyche) made my day

Cheers,

- Pete

[Mikhail]

Don't speak too soon, Pete. I have recently seen the Maculinea species placed in a genus new to me- Phengaris.

Misha

[Padfield]

Indeed.

See http://tolweb.org/Phengaris/112250.

I was hoping that one would just go away if we all ignored it.

G

[Dave McCormick]

Last I heard, the masseyi Silver-Studded Blue was found only in North Wales so if its gone from there or not been found, then it could be extinct.

[Pete Eeles]

Last I heard, the masseyi Silver-Studded Blue was found only in North Wales so if its gone from there or not been found, then it could be extinct.

Hi Dave - this subspecies was, as far as I know, only ever known from mosses in north west England.

Cheers,

- Pete

[Padfield]

This is the section of the 'tree of life' published at the URL I posted above:



It's interesting because if it's accurate it really is the death-knell of Maculinea. As the site points out, the type species of Maculinea is alcon. That means that if you want to retain the genus, alcon must be in it. But the only way arion could also be in it would be if all those Phengaris species were also in Maculinea - i.e., Maculinea would have to replace Phengaris entirely - because arion is on a different basal branch.

Guy

EDIT: The link to this image doesn't seem to work very well - copyright protection no doubt. You'll have to use the website link in my earlier post to view it.

[Pete Eeles]

Indeed.

See http://tolweb.org/Phengaris/112250.

I was hoping that one would just go away if we all ignored it.

G

Hmmm. While I appreciate the various initiatives that keep popping up - the lack of any coordination between them is truly depressing since it makes things worse, not better. I'm so glad I didn't take up taxonomy as a career

Cheers,

- Pete

[Dave McCormick]

Last I heard, the masseyi Silver-Studded Blue was found only in North Wales so if its gone from there or not been found, then it could be extinct.

Hi Dave - this subspecies was, as far as I know, only ever known from mosses in north west England.

Cheers,

- Pete

Well according to this BC report: http://www.butterfly-conservation.org/u ... n_plan.pdf

The British population has four subspecies: P. a. argus is the lowland heathland form
found throughout its current range; P. a. caernensis occurs on calcicolous grassland in
North Wales; P. a. cretaceus is now confined to calcicolous grassland in Dorset; and P. a.
masseyi is a form found at a single moss site in Wales being extinct from Cumbria and
Scotland. The genetic distinctiveness of these races is currently under investigation

And according to this PDF: http://www.conwy.gov.uk/upload/public/a ... d_Blue.pdf

The silver studded blue has undergone a severe decline in range this century, estimated at 80%. It has become extinct in Scotland and northern England, and throughout most of central, eastern and SE England. It remains widespread only on the heaths of Dorset and Hampshire, although strong populations also occur in North Wales. The British population has four sub-species: P.a. agus is found throughout its current range; P.a. masseyi is a form now only found at one site in North Wales; P. a cretaceus is confined to calcareous grassland in Dorset and P.a.caernensis is endemic to some parts of North Wales.

I don't know much about the species since I don't live in a lace that it ever existed, so just going on what I am reading in various reports.

[Pete Eeles]

Thanks Dave. I'm also no expert here - so some comments before someone "in the know" pops by ...

1. The BC report is from 1996 and I'm not sure when masseyi became "extinct" according to certain authorities. This report may well pre-date that extinction.

2. I was unaware of any claims that masseyi existed in Wales - so thanks for that too! Although I'm suspicious of the claim being made since the only reference to it seems to be that one report!

Anyway - I hope we get to the bottom of this soon!

Cheers,

- Pete

[Piers]

Hi Pete, Dave...

Ssp. masseyi (if it could actually be described as a separate subspecies) was found on the mosses of Lancs, Westmoorland, etc. and became extinct in the 1940's following a fire on the final site at which it was found. Until recently the race was deemed extinct and the name with it.

Adrian Riley in his infinite wisdom chose to resurrect this name and apply it the the colony on Prees Heath. However, very few people actually subscribe to this theory and as far as I am aware there is no evidence to actually substantiate this claim.

There is a worrying trend to apply subspecific status on a whim and if the UKB website is to be taken seriously I firmly believe that it should follow accepted conventions (ie. Bradley,J.D. Log Book of British Lepidoptera. 2000) and not become a maverick in this respect.

In fact, even in his book, Riley is non-committal about this; on the one hand declaring the ssp. extinct and then applying the term ('Northern Silver Studded Blue') only to state that (in his opinion) specimens from Prees "conform closely" to Masseyi. Apart from the page heading he doesn't actually state that the Prees colony actually is masseyi.

Even the use of ssp. cretaceus is flimsy: cretaceus was the subspecific name given to the colonies on the chalk in south east England which exhibited certain characteristics that could (if you squinted) be used to differentiate them from the nominate ssp.
For some unknown reason in 1984 Jeremy Thomas resurrected the name and applied it to the Portland colonies simply because they occur on a chalk promontory. Historically the Portland colonies were accepted as ssp Argus, the same as the other chalk and limestone colonies in Dorset, somerset and Wiltshire!!

Cretaceus was a different beast altogether from the Portland colonies, and the characteristics that lead to them being classed as a separate subspecies from argus are not shared by those butterflies found on Portland. Even having said that though, there is no substantial reason why the Kent Sussex chalk colonies should have been classed as a separate subspecies. The silver studded blue is an extremely variable butterfly and prone to producing geographically separated clines; one only has to look (for example) the magnificent race from the Cornish dune systems, which differ considerably again from those Cornish colonies that occur inland.

The use of cretaceus for the Portland colonies has been adopted by some but not by others. Bradley and Fletcher (1979) state 'Kent' as the the only locality for ssp. cretaceus, however Bradley (1998 and 2000) for some reason repeated Thomas's claim. The idea that the colonies on Portland are a subspecies does not do not stand up to scrutiny.

There is considerable doubt over whether 'masseyi' could ever be classed as a true subspecies, and there is certainly no evidence whatsoever that the colonies on Prees or in North Wales are anything other than argus. The trend to label them masseyi is nothing more than that; a trend in applying arbitrary subspecific labels on a whim.

It is quite correct that the UKB website should follow the Bradley (2000) checklist for subspecific forms. Bradley is the accepted standard in this regard (for the list of species on the British list) and if we veer away from that then I can list a good few other mooted subspecific forms that we could also apply (Roger Dennis lists a few more) and the result would be chaos.

Felix.

[Piers]

Interestingly the BC document does contradict itself. While at the start of the document it labels the Welsh colony as Masseyi, further into the text we read:

One mossland population remains (in North Wales) although the
species was once widespread in this habitat, especially in Cumbria (P. argus masseyi).

With regard to the flimsy nature of these subspecific classifications the document also admits:

The classification of these subspecies is based primarily on the size and colouration of adults
(Emmet & Heath 1990), but their status is uncertain (Dennis 1977, Thomas 1985a).

The one thing I would add that is that if there is one colony that deserves to be split from ssp. argus, then it may be the north welsh moss colony, which has been utterly separated from any other uk colony for in many thousands of years. However, although some specimens from this colony do bare a resemblance to some specimens from cumbria and Westmorland that is surely not a firm enough base upon which to make a subspecific split (and the only people who have made this split are the authors of the report!), and in all likelihood genetic testing will reveal that the welsh colony is utterly distinct from the extinct ssp. masseyi as it's origins are different.

Felix

[Mikhail]

While we're on the subject of the Silver-studded Blue, I have noticed on this site, and elsewhere, photos of this species from Norfolk and Suffolk which strike me as far more distinctive than any of the minor local variants alluded to above. They have unusually narrow dark borders to the male forewing uppersides; so much so that if I had not known the place of origin I would have suspected Idas Blue. I am not being entirely frivolous when I ask if it is possible that the Idas Blue might exist unrecognised in East Anglia. From a biogeographical point of view it would make sense, after all the species used to occur on heathland in the Netherlands together with the Silver-studded Blue, although now sadly extinct. I have no personal experience of the species in East Anglia, so am quite prepared to be shot down in flames by those who know better.....

Misha

[Padfield]

I only know the Martlesham Heath colony in Suffolk, which was very active in my childhood. That was definitely silver-stud and not idas.

What foodplant did the heathland idas take in the Netherlands, Mikhail? I'm not aware of them taking heather.

On the broader question, and taking the philosophical perspective rather than concentrating on particulars, it's worth stating Kudrna's dictum that the only natural taxa are the individual and the breeding community. All other taxa are created somewhat artificially, for the convenience of humans. Species and subspecies are definitely not natural taxa (as a mathematical exercise, while teaching group theory, I investigated whether it was possible to define 'species' so as to make 'same species' a mathematically valid equivalence relationship - it wasn't - it isn't!!).

Guy

[Mikhail]

Guy, the Dutch Idas fed on heather (struikhei) according to De Dagvlinders van Nederland.

Misha

[Piers]

Hi Misha,

You've illustrated perfectly why the present subspecific splitting of argus is arbitrary at best (with the exception, of course, of ssp.caernensis).

I concur with your observations of the Suffolk SSB's and this supports my assertion that SSB''s (certainly in the UK) are simply exceptionally prone to producing local 'forms' throughout their range. My personal favourites are the populations found on the Cornish dune systems; certainly the largest specimens in the UK (noticeably larger on average than the so called 'cretaceus') with a trend for exceptionally well marked (and huge) females showing massive yellow-orange and pronouncedly curved lunules on the upperside of all four wings.

Some Cornish colonies also produce a high proportion of blue females, and I would doubt (from my observations) that the proportion of blue females is any greater in the Shropshire colony, which kind of scuppers the 'masseyi' theory, which is currently applied purely on the flimsy grounds that Prees Heath females are prone to being blue scaled. In fact, the only colonies that seem to produce consistently brown females are those on the South Dorset and New Forest heathlands.

If I were to nominate a population for subspecific status it would be these Cornish colonies, on the grounds of size, markings, emergence time (from late May) and the propensity towards bivoltinism. A much stronger case than demonstrated in the apparently desperate attempts to assign the old label masseyi to populations in Shropshire and North Wales.

Felix.

[Mikhail]

Felix, I agree with your views. The proliferation of "sub-species" is even worse in the Iberian peninsula: Manley and Allcard list no fewer than 18 sub-species of Silver-studded Blue in their Field Guide. This only goes to devalue the concept of sub-species, which surely should be reserved for distinct geographical or ecological races, which might be well on the way to speciation. The Alcon and Mountain Alcon Blues would be a good example, as these are now generally regarded as con-specific. Also the ssp celadusa of the Heath Fritillary, which was originally thought to be a distinct species until it was discovered that there was a broad zone of hybridisation in France.

Misha

[Matsukaze]

Don't speak too soon, Pete. I have recently seen the Maculinea species placed in a genus new to me- Phengaris.

Misha

It won't be long before a Ph.D in taxonomic history is a requirement for doing a Google search.

[Zonda]

Pete said

Hmmm. While I appreciate the various initiatives that keep popping up - the lack of any coordination between them is truly depressing since it makes things worse, not better. I'm so glad I didn't take up taxonomy as a career

Me too... This is the very thing that kindled the killing of my interest in fungi,,, in the end it becomes an unholy mess. I have given up even thinking about these things.The trouble is it leaves you out on a limb,,,somewhat. I suppose that nothing will, or ever has been really confirmed, and taxonomy is always in a state of flux anyway. People say,,,"it's only a name, a label", but it is a bit like not knowing your own name. The trouble with human beings, (and i include myself in that) is we have got to know, and knowledge is our food, to a certain extent. Sometimes i yearn for the days when i just looked at the world in wonder, and all Leps were just 'butterflies', and all fungi were just mushrooms. I'm finding that it's best to let other people tear their hair out over these labeling issues. This does not detract from my appreciation of the natural world tho.
PS As it happens taxonomists are themselves becoming extinct. Where does that leave the rest of us?