High Brown or Dark Green id?

[tomdunbar]

I had late sightings of possible High Brown/ Dark Green frits yesterday at one of my regular sites here in Cumbria. The one posted here is a very worn individual, hardly surprising at this stage in the flight season. I managed to positively id (underwing) a separate DGFr but this second Large Frit took to the skies before I could manage a view of the underwing.
I've had 28 positively identified HBs this flight season spread over ten sites. Of course they were amongst many more unidentified Large Frits (HBs/ DGs) which were recorded as such.
I have improved my High Brown id skills this season, and use the easy underwing extra row of small silver spots as previously (assuming a good view). Use of the upperwing offset third dot near the apex has proven reliable supported in many cases with good views of the underwing. Use of the upperwing convex wing edge shape and raised scent brands techniques I haven't mastered though.
In the field I felt that the attached Large Frit was High Brown. However looking at the photographic evidence later raised doubts!
I would greatly appreciate if anybody could throw further light on the question.
Ah, cloudy skies breaking up - a return visit in the offing after a cuppa.

[Pieter Vantieghem]

A very difficult one. I've made an image some time ago for a Dutch forum with uppersides of the females of the 3 Argynnis look-a-like species. The pictures of the collection specimens are from the Dutch website http://www.vlindernet.nl. A. aglaja has the submarginal dots mostly on one line while in the other 2 species the 2 most apical spots are lying outside the line. Because of this and also because I would expect A. adippe to have a bit bigger solid black spots in the central cell. I would think this is A. aglaja, although front wing shape could be a bit more rounded to be a typical one but maybe that's due to the position of the wings and to the fact this individual is very abraded.

edit: apparently the image doesn't show very well here so maybe best to copy the image url and put it in a new tab. I try to fix a smaller image....

[Pieter Vantieghem]

This looks better, most probably:

[David M]

My first instinct was High Brown Fritillary, mainly because of what Peter has indicated above, i.e. the displacement of the 3rd submarginal spot. There's no sign of the sex brands on the forewings, so female HBF for me.

[Chris Jackson]

Thanks for the tutorial, Pieter. Very interesting, I will try and retain some of that.
Chris

PS: Hi David, you got in just before me
obviously female HBF

[tomdunbar]

Thank you guys for your help. You have confirmed by initial judgement in the field.
I returned to the same site today Friday in the hope of locating another High Brown. I had a Dark Green immediately on arrival and despite being very worn had no difficulty in identification, both upper and underwing showing well. This was followed by another two nectaring on thistle and ragwort respectively.
The real bonus was a perfectly behaved High Brown on the last stand of knapweed as I was about to exit the site at 17.35. I often find late afternoon a good time to get good views of the fritillaries as they often nectar before retiring to their roosts.

I have had a small number of High Browns this flight season with an empty space where the 3rd submarginal spot might be expected. However Pieter's system above overcomes any confusion that might arise.

Some time ago I noted that in Thomas's Butterflies of Britain and Ireland a difference is shown for Dark Green and High Brown on the upperside of the hindwing. I got very excited to see that the submarginal pattern of dots from the bottom up in the Dark Green follows large, large, small, large, large. The last two for High Brown shows large,small. Testing this in the field was very disappointing when I discovered that the last two dots are obscured by the forewing in both species!

2015 has been a very late year for emergence of most species. I have got my fingers crossed to take advantage of this with a September High Brown sighting next week. Do you know of any such records?

[jenks]

Thanks Pieter for those images and the accompanying text. Here in south Wales we are lucky to have a site where DGF and HBF are on the wing at about the same time ( as David and others will confirm ! ) and identification of the 2 species often presents problems ( well to me anyway). The info you have given will be very useful in helping with ID. Just have to wait for next year now !

[Pieter Vantieghem]

I must admit that I should test this feature on for example collection specimens. I have tested it a bit on pictures on an observations website widely used in the Netherlands (where aglaja and niobe fly together) and Belgium (where aglaja and adippe fly together). But testing it on collection specimens should make it more solid.

[David M]

I have had a small number of High Browns this flight season with an empty space where the 3rd submarginal spot might be expected.

This is quite common in High Browns, Tom. I have never seen a Dark Green completely missing this spot, though quite frequently it is noticeably smaller than the two above it.

[tomdunbar]

Hi David
Like you I have never seen the empty space in a Dark Green. Using Pieters technique should confirm it with or without the 3rd dot.

Thanks

[njs5870]

This looks better, most probably:

As an aside, why in guides are butterflies portrayed like this when they never appear like this in real life?

[bugboy]

This looks better, most probably:

As an aside, why in guides are butterflies portrayed like this when they never appear like this in real life?

I would hazard a guess and say convenience...