argus vs idas

[Padfield]

I wondered where you were, Roger!

I'm at school at the moment, but it suddenly occurs to me there might be a photo of the real spine (not the mid-leg spine, which they all seem to have!) in Lafranchis 1 (the original, Papillons de France, Belgique et Luxembourg), which I think you also have.

I thought your pictures were excellent, but I didn't think they showed the relevant spine, which is why I didn't refer to them before. This is definitely a project for 2010!

Guy

EDIT - there is a huge blow-up of a male argus in that book but you can't see the tibial spine on the front leg even so. He does mention in the text that the spine is visible best when the lower part of the leg is bent forward, which seems to push the spine up. He also mentions that there is a spine on pylaon, in the same place, so you might be able to see it on your super-close-up pictures you took when you were last with me, Paul:



Guy

[Paul]

Brilliant Roger... will have a long slow look at your reasoning next time I have the same question

(Edit)... Sorry Guy.... crossed yet again.... sigh... lovely memory - here's the one.... I've done my best with the close ups.... quality sucks when put next to Roger's tho'







no spines to my eye!!

[Padfield]

Roger's pictures are absolutely brilliant but he is definitely looking at the wrong spine! It is not the one pointing backward, which you will find on them all - and is particularly strong on the mid-leg. It is only on the foreleg. This is from the Swiss Bible (the word after 'pattes', at the top of the next column, is 'antérieures'):



It is very difficult to see except when the lower part of the leg is bent forward.

Guy

I think it might be visible on this picture of pylaon I took this year:



Paul - there's definitely some kind of weird time warp between the UK and CH today. Can't hold a proper conversation...

[Paul]

well.... just been through all my English argus shots and can't make out a single spine, not that they're not there, but camera not good enough..... so.... come on everyone - first foreleg spine showing well in the right place wins

Aaaaagh Guy - dunnit again!!

[Padfield]

... and now I know what I'm looking for I can see it on many of Roger's pictures. It appears as a dark tapering at the end of the tibia, with the free hook itself not always visible. 'Hook' seems to be a better word than 'spine' - we have all been looking for something projecting from the leg, but it's more about the shape of the end of the tibia, terminating in a hook-like extension.

Yippee!!

Guy

[Roger Gibbons]

Guy, you were right, I was looking at the wrong spine, although the books carefully omit to mention that there is a whopping great spine on the midleg whereas the foreleg hooked spine is almost invisible, being small, darker in colour (or so it appears) and pointing backwards often obscured from view.

This solves one big question, in that the midleg spine is not characteristic of argus, because, as mentioned, I have photos of what I am sure are idas with this same spine.

The Lafranchis France book does have a large photo of a rather moth-eaten (!) argus but you cannot really see the foreleg clearly and there is no sign of a hook-type spine.

I have been having a close look at my RAW files blown up and I think I may have a photo of the foreleg spine, not very clear against the background, though. I have put it up as a link http://www.butterfliesoffrance.com/argu ... _11898.htm as I think there is an 800 pixel-width limit on UKB and the photo needs to be a bit bigger to see the spine, indicated by the blue line.

So, is this finally the hooked spine?

[Padfield]

Hi Roger,

The 'spine' can't point backwards. It's not the thin, curvy hook you indicate on your picture but the structure on the front of the leg, that I think is also visible in your picture.

Guy

[Roger Gibbons]

Hello Guy,

I did have doubts that this was the actual spine, as may have been apparent from my hesitant language. It was not forward-pointing as Lafranchis illustrates and was not the same shape, being rather too curved compared to the straight-looking spine shown by Lafranchis. Higgins & Riley describe as a strong spine. I have seen it described as a hook (I cannot now find the source of this), but maybe they were looking at the same “spine” as I illustrated.

I have to say that if it is this obscure i.e. none of us can see it even using the high quality cameras we are all using, it is not of much value in a field guide. It is really only of value if the specimen is caught and examined under a microscope or strong lens, in much the same way as the genitalia.

Which leads me on to something on which I have strong feelings: only accredited scientists and entomologists who NEED to know the exact ID should be catching and examining specimens in a way that causes distress if not death. I exclude netting, examining (without bottling) and releasing which, if done with care, such as keeping them for a minute or so in the shade, does not cause distress. Encouraging non-expert enthusiasts to examine genitalia of specimens (often of rare and threatened species, else why do it) is not a good idea.

Roger