Erebia sthennyo

False Dewy Ringlet (Erebia sthennyo)

2023 photographs highlighted in green. Click on any photograph to go to an enlarged picture, or simply scroll down the page.


46259_male_Hautes-Pyrénées_5Jul19	46275_male_Hautes-Pyrénées_6Jul19	46279_male_Hautes-Pyrénées_6Jul19	51295_male_Hautes-Pyrénées_7Jul23

51315_male_Hautes-Pyrénées_7Jul23	51314_female_Hautes-Pyrénées_7Jul23	43916_female_Hautes-Pyrénées_08Jul17	48044_female_Hautes-Pyrénées_3Jul21

48080_male_Hautes-Pyrénées_3Jul21	46269_male_Hautes-Pyrénées_5Jul19	46262_female_Hautes-Pyrénées_5Jul19	46265_female_Hautes-Pyrénées_5Jul19

A very local and uncommon Erebia limited in its distribution to the central Pyrénées. 43916 was the only sthennyo I had seen until 2017, despite several trips to the region. And I was - and am still not - entirely convinced that 43196 is sthennyo.

Other high altitude Erebia fly in company with sthennyo, including the Mountain Ringlet (E. epiphron), Gavarnie Ringlet (E. gorgone) and the Pyrénées Brassy Ringlet (E. rondoui). The Dewy Ringlet (E. pandrose), which it superficially resembles, also flies in a small area in the Ariège département of the eastern Pyrénées, and their ranges overlap slightly.

It can be differentiated from pandrose in that pandrose has a wide upf post-discal band with four ocelli and a clear discal line on the inside edge of that band. Also the red areas around the sthennyo ocelli tend to just "surround" the ocelli. The undersides of the two species are different, at least to the extent that differentiation should be possible, so an underside view should be definitive even if an upperside view should leave room for doubt.

The unh discal lines are different between pandrose and sthennyo for both sexes. The lines are much more pronounced for pandrose and in the case of the males, the discal line is more jagged in pandrose. The lines are not that different in shape for the females of the two species, but the pandrose line is much stronger.

The identification clue relating to the upf red post-discal band "hugging" the ocelli seems to be principally applicable to the male as the illustrations of the female in T&L show a rather wider and more diffuse band. I have not had a clear view of a definitive female upperside so I am unable to say whether this is the case, based on personal experience.

The unh of the sexes are different in that the male has a more pronounced discal line and the shape of the discal line is different between the sexes, the female discal line being rather more jagged.

In 2019 I returned to the same location that I had visited in earlier years. I found that they tend to stay close to damp areas and that may be the key to finding them, even within their known localities.

It seems to be to be a very nervous species, difficult to approach, the more so that it frequents damp areas. It has a weak flight but rarely stops and when it does, it settles deep in the grass with closed wings. So the underside shots on this page from 2019 are distance shots and rather obscured by blades of grass.

The flight period is said to be late June to early August. However, even in the very late year of 2019, every specimen I saw was quite worn even at the end of the first week of July. Subsequent visits in 2021 and 2023 in the first week of July found significant degrees of wear, and it seems that late June might be the best time to see them fresh.

ref	sex	observations	alt. m
46259	M	a male, that the red upf band seems to be rather diffuse may be a function of ageing.	2070
46275	M	a male, also quite worn.	2070
46279	M	a male, nearer to the expected norm of the red band hugging the ocelli.	2070
51295	M	a male, but I am not at all convinced it is sthennyo, but equally I am not convinced it is epiphron, the only other contender. The ocelli are not large or round and the red surround is not circular.	2070
51315		a male, clearly sthennyo. It looks quite fresh from the dark brown ground colour and would have made a nice image if it had not lost a section of the upf apex, and settled deep in the grass as they are wont to do.	2070
51314		a female, rather bedraggled but to a lesser extent than some on this page.	2070
43916	F	with numerous Erebia flying in the region, often difficult to photograph, my objective was to take photographs first and later assess what I had seen. This was not the moment to try to remove the intervening blade of grass! It has been suggested that 43916 is actually epiphron, and not sthennyo, principally on the grounds that the upf series of post-discal spots should be nearer to the margin in sthennyo. This may well be true, although 43916 was flying in company with numerous epiphron but noticeably different in terms of its colour (43916 was much darker), the width of the red post-discal band (the epiphron bands were much wider), and to some extent the upf black post-discal spots (the epiphron spots were generally larger and many had white centres). I planned to revisit the location in 2019, when hopefully I would be able to get an underside shot, which would be definitive as sthennyo and epiphron are very different. 2019 footnote: I did indeed get some underside shots which confirmed sthennyo, but it did not resolve the conundrum of 43916. However, having seen numerous sthennyo at this site, I am more inclined to believe that 43916 is in fact sthennyo on the grounds that the red band hugging the ocelli is not as pronounced in the female as the male, so the fact that it is not hugging the ocelli is not as relevant.	2070
48044	F	a male underside. I believe it to be a male mainly on the strength of the grey colouring which indicates male rather than brownish, which would indicate female, as is often the case for the undersides of many Erebia species. Lafranchis, in his book TLID, states that the unh markings are indistinct, strongly implying that this is a characteristic to define sthennyo as compared to *pandrose; 48044 would seem to dispute this, as the markings, especially the discal line, are very distinct. There is no doubt that 48044 is sthennyo* as pandrose does not fly in the Hautes-Pyrénées and only flies in the Pyrénées in a limited region in Ariège in the east, and it appears likely that the two species do not fly together anywhere in the Pyrénées.**	2070
48080	M	a female, just. A rather battered specimen, very much at the end of its flight period, even on 3 July, and for a female. I had hoped to be able to see fresh sthennyo by visiting this location (the only place I have ever found this very localised species), but this did not turn out to be the case, despite 2021 being a "late" season for almost everything else. I have included this photograph to illustrate the wide upf post-discal band of the female, showing that the red "hugging" the blind ocelli is limited principally to the male, and is not a defining characteristic of this species.	2070
46269	M	another distance shot, at least this time with a clear view. The discal line is not quite a pronounced as 46269.indicating that it is a male.	2070
46262	F	a female as indicated by the weak and almost indiscernible discal line.	2070
46265	F	a female with a jagged discal line, clearly indicating female, and strong contrast across the line.	2070