MikeOxon

[Wurzel]

Interesting aberrations Mike. I'm not sure about Polonus as I don't too much about them - I do seem to recall seeing a similar Adonis a few years back and thought it was the aberrnat 'scalens'?

Have a goodun

Wurzel

[MikeOxon]

Thanks for looking in, Wurzel. I've only read a few descriptions and had hoped one of our entomologists might have a look. I've seen Adonis with some degree of spotting before, but never to this extent.

Mike

[William]

Those putative polonus are lovely butterflies, Mike - look forward to seeing what the experts have to say

BWs,

William

[Pete Eeles]

I also began to realise that there was something unusual about many of the individuals - the blue was brilliant but rather pale and, when I got a close view, there was a distinct line of dark spots along the trailing edge of the wings.

Hi Mike - polonus is defined (in Goodson and Read) as:

"Male of a tint half way between bellargus [Adonis] and coridon [Chalk Hill]". The definition makes no mention of spotting or dark markings. Given the state of the individual, I think it would be difficult to claim this as polonus, given the natural fading that occurs. However, I still think it's aberrant, based on the markings. Given the number of bellargus abs, I'm not sure which it is!

Cheers,

- Pete

[MikeOxon]

Given the number of bellargus abs, I'm not sure which it is!

Thanks for responding Pete. My interest started from your description on the species pages of this site : "....... It is well worth looking out for this hybrid at sites where both species fly together. Polonus is encountered within the spring brood of Adonis Blue."

A Google search unearthed various illustrations, all of which showed the spots on the hind wings, and I found more description at http://www.d-e-zimmer.de/eGuide/Lep2.1-Po-Py.htm where there is discussion as to whether polonus is a 'true' species or a hybrid. I found more about this in a paper "Bad species" by Descimon & Mallet http://www.ucl.ac.uk/taxome/jim/pap/des ... 0print.pdf, who state "L. × polonus (Zeller 1845),formerly mistaken as a good species from Poland and later recognized as a hybrid (Tutt 1910). These hybrids occur wherever the parent species fly together, although their frequency varies widely. Lysandra coridon is univoltine and flies around August, while L. bellargus is bivoltine and flies in May and September; the hybrid flies in late June."

This last reference implies that the hybrids are not that uncommon at appropriate locations and it is, perhaps, significant that the specimens I saw were quite fresh, whereas bellargus at the same site were very worn.

My best 'lead' came from Howarth's "South's British Butterflies"(1973), which states "Male specimens that are intermediate in colour between bellargus and coridon are thought to be natural hybrids between these two species, as apparently they only occur in localities where these two butterflies are present. A specimen of this rare butterfly known as polonus Zeller is figured on Plate 15, 28"

It's important to know that these hybrids are male and that my photographed specimen revealed his interest in the female bellargus that were present! Many of the bellargus aberrations are females, which frequently show blue uppersides with marginal spots. These can all be ruled out.

I guess that this is one of those cases where a scientific study requires a net and a killing jar, which I did not happen to have with me

Last but not least, however, I spotted the following at http://www.sussex-butterflies.org.uk/ol ... y2010.html - "I must report an exciting find on Mill Hill, back on 19th May. I noticed that one of the many Adonis Blue males flitting across the lower slopes looked a little different, and I immediately sensed that this was something special. As I clambered up to it, in a state of excitement, I strongly suspected (later confirmed by expert opinion) that this was Polyommatus coridon ab. polonus (Zeller, 1845), which in fact is not an aberration of the Chalkhill Blue at all! 'Pollonus' is the rare hybrid between the Adonis Blue and Chalkhill Blue, and more aptly attributed the label Polyommatus bellargus x coridon - for me, a bit of a 'mythical beast'. It clearly has characteristics of the males of both species. Although I didn't get a shot of the underside, this was very pale and more akin to the underside of a male Chalkhill Blue. Happy Days! (Neil Hulme)"

I'd try a PM to Neil, to see if his 'expert opinion' could be brought to bear, but he seems to have disabled personal messaging Perhaps, If anyone's in touch with him, they could point him in my direction?

Mike

[Willrow]

Most interesting Mike, your research makes for some informative reading. I'm sure Neil will eventually catch up with this post and present his well considered opinion

Regards,

Bill

"When in doubt - venture out"

[MikeOxon]

Thank you Bill. Now I've started looking, I keep finding more information (assuming that I'm on the right track!).

For example, in http://biostor.org/reference/116974.text, I've just read a more complete description of polonus: "Generally speaking, the colour of the upper wing surface is intermediate between bellargus and coridon, and is often described as similar to that of Agrodiaetus damon Schiff., with a more or less well-marked greenish tinge. There is a dark marginal border of variable width and a number of pre-marginal dots of variable size, more or less merged with the dark border. The underside may be more similar to bellargus (polonus, calydonius) or to coridon (hafneri, samsoni).

As a retired research scientist (though not a biologist), I find it hard to let go of these things

Mike

[Pete Eeles]

Hi Mike - some further thoughts:

This last reference implies that the hybrids are not that uncommon at appropriate locations

I can't believe this to be true - otherwise we'd have a lot more examples than we currently do! I know of only 2 confirmed polonus in recent years - Neil's being one of them.

my photographed specimen revealed his interest in the female bellargus that were present!

So how many individuals did you photograph - one or several? Also - if the male is bellargus, it's not surprising he's interested in the female

Many of the bellargus aberrations are females, which frequently show blue uppersides with marginal spots. These can all be ruled out.

Of the 141 bellargus abs, at least 100 of those apply to males (at first glance). ab. puncta is defined as: "Male with a row of well-defined little black spots in the margins of the hindwings upperside".

In terms of "tint", I believe that the following photos are of the same individual, but the tint is very different - so hard to be conclusive on this basis.

Cheers,

- Pete

[Pete Eeles]

Thank you Bill. Now I've started looking, I keep finding more information (assuming that I'm on the right track!).

For example, in http://biostor.org/reference/116974.text, I've just read a more complete description of polonus: "Generally speaking, the colour of the upper wing surface is intermediate between bellargus and coridon, and is often described as similar to that of Agrodiaetus damon Schiff., with a more or less well-marked greenish tinge. There is a dark marginal border of variable width and a number of pre-marginal dots of variable size, more or less merged with the dark border. The underside may be more similar to bellargus (polonus, calydonius) or to coridon (hafneri, samsoni).

As a retired research scientist (though not a biologist), I find it hard to let go of these things

Mike

Very interesting, Mike - and certainly fits your individual in terms of the submarginal border and spots. However, I'm not sure if descriptions can be extended in this manner without creating a new ab.

Cheers,

- Pete

[Pete Eeles]

I was reminded of this ab. seen a couple of years ago (unnamed Common Blue ab.) that looks similar to yours, Mike. The mystery thickens!

Cheers,

- Pete

[MikeOxon]

I was reminded of this ab. seen a couple of years ago (unnamed Common Blue ab.) that looks similar to yours, Mike.

That's remarkable - do you know where it was taken? Strange things seem to be happening in many places. I recall that nomad reported what looked like a Silver-studded Blue from Lough Down, last year viewtopic.php?t=7747&start=10000

Mike

[Pete Eeles]

Hi Mike - I believe that individual was taken at Magdalen Hill Down, in Hampshire.

Since we've corresponded privately on this subject, I hope you don't mind me "polluting" your diary with additional items we've found; this is one of the more interesting threads (well, for me, anyway!) I've participated in!

First off, while the definition of polonus is based primarily on the ground colour (and a nice rendition can be found at http://www.biologie.uni-erlangen.de/mpp ... ridon.html), the formal definition does, indeed, mention spotting also. The formal definition (Zeller, 1845) can be found at http://www.biodiversitylibrary.org/item ... 7/mode/1up.

I'm no German scholar, but Google Translate does, indeed, imply that spotting is mentioned.

Over and out!

- Pete

[MikeOxon]

Pete, you are always welcome to 'pollute' my diary. I'm pleased that you find it of interest.

I was holding back a bit from publicly writing loads of speculation, only to find it was all wrong! I got your PM and have sent the German to a linguist friend, so will forward it to you, when available. I had a go at the Latin myself but am getting that checked as well

Mike

[Padfield]

Yes, the spotting is mentioned in the German and the Latin. I won't translate the German here, as it's long and Mike has already sent it to an expert, but the brief Latin description (as I'm sure Mike will agree) runs:

"Wings silver-blue, with white fringe hairs alternating with black; the margin of the forewings more broadly black; on the hindwings above, a series of black spots (lit. ‘pimples’), beneath, (a series of) reddish spots before the hind margin. Male. Female unknown".

I decided to keep an eye open for polonus after Neil brought it to my attention but I have yet to see one in the flesh.

Guy

[MikeOxon]

Thank you for commenting, Guy. I'm afraid it didn't occur to me to send the German to you but I think I have it in hand. My Latin translation agreed closely with yours. From all that I have now read, my specimens do seem to correspond with the formal description of polonus. I suppose the other question is "what else could they be?" One of the references I gave earlier (http://biostor.org/reference/116974.text) seems to imply that various forms (abs) should actually be regarded as polonus hybrids. I'm still hoping to hear from Neil

[Jack Harrison]

That Common Blue ab

Very pale. Could that be a hybrid between Common and Chalk-hill Blue? After all both species are now in considered to be in the same genus Polyommatus.

Maybe Chalk-hill Blues will hybridise with several Polyommatus species. I wonder if there is any evidence of hybridising with other Polyommatus on the Continent?

Jack

[Neil Hulme]

Hi Mike,

Pete and Mark Colvin have brought this interesting topic to my attention and I will definitely get round to replying in time. My new job is keeping me so busy in the earlier stages that, when added to my continuing work as a volunteer for other species, I'm currently having to borrow time from a parallel universe. Things will settle down to a more manageable pace once HMS Fritillaries for the Future has left port heading in the right direction.

I have disabled my PM service for a while. This is because I have endeavoured to reply to butterfly queries within 24 hours for at least the last ten years, so a lack of response for many weeks would likely send out the wrong signal. I feel it's better to prevent questions being asked at the moment, than being apparently unwilling to respond. I hope that makes sense?

Best Wishes, Neil

[Jack Harrison]

Learned articles about Polyommatus hybrids.

http://images.peabody.yale.edu/lepsoc/j ... Downey.pdf

http://www.researchgate.net/publication ... aenidae%29

http://biostor.org/reference/116974

and doubtless many more with a web search.

So my suggestion about possible coridon x icarus is not totally absurd.

Jack

[MikeOxon]

Thank you, Neil. I understand the pressure you are under

Thank you, Jack. I think it is becoming apparent that, whereas hybridisation has long been recognised as common in the plant world, it is only since the application of DNA analysis that it has been seen as widespread in the animal kingdom as well.

The expansion of our understanding of the natural world through DNA analysis can, currently, only be achieved in the laboratory. This is one example of the need for ongoing collection of specimens, within the context of scientific study, as described in Mark Colvin's article in Dispar - http://www.dispar.org/reference.php?id=92

[MikeOxon]

I have just returned from a short trip to Exmoor, looking for the Heath Fritillary. I am very grateful to William, whose local knowledge save me a lot of searching time. I had also read a lot about the 'ticks' problem on Exmoor, so decided to adopt full PPE (Personal Protective Equipment), comprising 'NosiLife' treated shirt and trousers, with overlapping 'NosiLife' socks and boots recently sprayed with permethrin. I am pleased to report having no problems at all - I suspect the blighters ran the proverbial mile, when they saw me coming! [note that permethrin is considered to be a far more effective tick repellent than DEET]

The forecast for 16th June was good, although there was a little more cloud than I expected, initially. We (my wife and I) went straight to the Haddon Hill site and soon found ourselves surrounded by good numbers of Heath Fritillaries, some basking on the bracken and others nectaring, obligingly posing for both open and closed wing photos.

Haddon Hill, Exmoor - 16th June 2015
Olympus E-M5 with 40-150 lens - 1/400s@f/7.1 ISO400

Previously I had only watched this species at East Blean Wood in Kent, so it was interesting to compare and contrast the sites. The epithet ‘Heath’ seems to apply more accurately to Exmoor but there were many similarities in the bracken filled clearings on the edge of woodland, liberally sprinkled with Cow Wheat flowers. Another similarity seemed to be that the Heath Frits were virtually a ‘mono-culture’ in their chosen location.

Haddon Hill, Exmoor - 16th June 2015
Olympus E-P1 with 17 mm lens - 1/250s@f/5.6 ISO200

At first, the butterflies seemed somewhat sparser than in Kent but, soon, I began to see small groups – in one case, a three-some spent some time pursuing each other, close around me, as though I were some sort of roundabout! Although these were too close and too fast for photos, I did get some other shots of group interactions:

Haddon Hill, Exmoor - 16th June 2015
Olympus E-M5 with 40-150 lens - 1/1000s@f/5.6 ISO400

Haddon Hill, Exmoor - 16th June 2015
Olympus E-M5 with 40-150 lens - 1/640s@f/8 ISO400

I should have done more reading before my trip as a subsequent read of Thomas & Lewington explained how the females often lay their eggs on the underside of bracken leaves and it is up to the caterpillars to find their way to nearby Cow Wheat plants. I suspect that the following photo may show egg-laying, while the butterfly is simultaneously nectaring!

Haddon Hill, Exmoor - 16th June 2015
Olympus E-M5 with 40-150 lens - 1/320s@f/8 ISO400

William had accurately predicted that I would see Green Hairstreak and Large Skippers, on the walk-in to the HF hot-spot, and the heath was being grazed by Exmoor ponies, with their ‘mealy’ muzzles in evidence.

Haddon Hill, Exmoor - 16th June 2015
Olympus E-M5 with 40-150 lens - 1/500s@f/8 ISO400

After a very satisfying visit to this site, we travelled down the hill and parked by the church in Upton, in order to visit the BC reserve known as Haddon Moor. We were enthusiastically greeted by a couple of ponies at the gate and then started to make a circuit around the reserve. The clouds had built up quite considerably by this time, and there was no sign of any butterflies on the wing, but this was compensated by a fine display of Heath-spotted orchids and one very robust specimen of a Southern Marsh Orchid

Haddon Moor reserve, Exmoor - 16th June 2015

Eventually, in one of the patches of sunshine, we spotted a couple of Small Pearl-bordered Fritillaries on the wing, though these disappeared instantly, when the next cloud moved in. This behaviour remained characteristic of our visit and I managed no more than a couple of record shots of this species, although there were clearly several individuals present (c 10?), judging by the brief bursts of activity during sunny intervals.

Our next stop was the car-park near the dam at Clatworth Reservoir where, again thanks to William’s advice, we quickly found the Small Pearl-bordered Fritillary ‘hot-spot’ down the path towards the fly-fishing centre.

Clatworthy Reservoir, Exmoor - 16th June 2015
Olympus E-P1 with 17 mm lens - 1/640s@f/8 ISO200

The butterflies were certainly abundant here, but photographing them was another matter altogether! They behaved like perpetual-motion machines, constantly skimming over the grass in an unending search for females. Sometimes, they would investigate a spot for a few moments, without ever actually landing. On the odd occasion, when one did pause, it was immediately ‘dive-bombed’ by another individual and forced to continue its relentless search. I wonder if this is a selection process, to ensure that only the fittest males finally reach a lurking female? As time wore on, I began to despair of getting any photos, except for one extremely worn specimen that seemed ready to give up the game of chase. There were several Large Skippers, which were a little easier to photograph, as well as many bright male Common Blues: After my recent observations on ‘spotted’ Adonis Blues, I noticed some spots on the wings of this male Common Blue.

Clatworthy Reservoir, Exmoor - 16th June 2015
Olympus E-M5 with 40-150 mm lens - 1/800s@f/9 ISO400

Clatworthy Reservoir, Exmoor - 16th June 2015
Olympus E-M5 with 40-150 mm lens - 1/800s@f/9 ISO400

As the afternoon wore on, the chase did seem to slow down a little and we found a Large Skipper and an SPB Frit rather surprisingly co-existing on a thistle. The extraordinary agility with which the butterfly could direct its proboscis deep into individual florets on the thistle flower was fascinating to watch. It still proved difficult to get an underside view of the Fritillary, which I find the clearest distinction between the two Pearl-bordered species

Clatworthy Reservoir, Exmoor - 16th June 2015
Olympus E-M5 with 40-150 mm lens - 1/640s@f/9 ISO400

Clatworthy Reservoir, Exmoor - 16th June 2015
Olympus E-M5 with 40-150 mm lens - 1/640s@f/9 ISO400

Clatworthy Reservoir, Exmoor - 16th June 2015
Olympus E-M5 with 40-150 mm lens - 1/640s@f/9 ISO400

One specimen of SPBF was paler coloured and had very lightly spotted markings on its upper wings:

Clatworthy Reservoir, Exmoor - 16th June 2015
Olympus E-M5 with 40-150 mm lens - 1/800s@f/9 ISO400

We finished our day with a drive over the moors around Dunkery Beacon before dropping down into Porlock and then following the main roads back to Taunton, where we stayed overnight. From the viewpoint near Dunkery, we could see bracken burning on one of the hill sides, which is, apparently, an important component of conservation for Heath Fritillaries.

The following day (17th June) started dully overcast, with a little drizzle, so we decided to head up the coast and take a walk along the ridge at Sand Point. Inland, the clouds looked very heavy and rain-filled but it was a lot brighter out to sea and, eventually, a few shafts of sun managed to break through. The wind remained quite strong and there was very little hope of seeing any butterflies, although I did spot one Common Blue, well hunkered down in the grass, just moving around a little, as though flight might soon be a possibility!

Sand Point - 17th June 2015
Olympus E-M5 with 40-150 mm lens - 1/320s@f/6.3 ISO400

Apart from that, the only other species I saw was a few Speckled Wood.individuals in the woods alongside the path from the car-park The absence of butterflies was compensated by the remarkable flora long the rocky spur and also by the number of nesting birds, including many Whitethroats and Linnets, amongst others.

Throughout the trip, my Olympus OM-D performed very well and, although I used my Tamron macro lens occasionally, I found that the 40-150mm Zuiko zoom proved very versatile as a ‘butterfly’ lens. Rather than changing lenses, I also carried an Olympus Pen, with a 17 mm lens, which I used for general and habitat shots.

Mike