Cupido alcetas

Provençal Short-tailed Blue (Cupido alcetas)

2025 photographs highlighted in green. Click on any photograph to go to an enlarged picture, or simply scroll down the page.


0791_male_Alpes-Maritimes_21May06	37218_male_Alpes-de-Haute-Provence_12May15	53839_male_Ariège_08Jul25	53864_female_Ariège_08Jul25

39217_female_Lot-et-Garonne_26Jul15	9143_female_Dordogne_13Aug07	9188_female_Dordogne_14Aug07	33966_male_Rhône_17Jul13

9099_male_Dordogne_13Aug07	38683_male_Ariège_18Jul15	53850_male_Ariège_08Jul25	38363_female_Drôme_10Jul15

38568_female_Ariège_16Jul15	22437_female_Hautes-Alpes_16Jul10

Alcetas is very similar to the Short-tailed Blue (C. argiades), usually slightly smaller, but principally differentiated by:

1) unh marginal lunule(s) (s1c and s2) adjacent to the tail:

argiades lunules orange-filled.

alcetas no trace of orange (maybe a few orange scales, apparent only on very close examination).

2) length of tails:

alcetas very small tails, maybe only 1mm in length, sometimes so small that only the "bump" in the marginal line indicates their existence.

argiades tails are usually slightly longer, maybe 2mm.

3) ups black borders (males):

alcetas tends to have thinner borders.

argiades thicker borders (see photos for illustration), and sometimes black marginal spots.

4) female:

alcetas upperside entirely black with no trace of blue scales, and otherwise unmarked.

argiades mostly black, but usually has areas of blue scales in the basal region and an orange spot at the uph anal angle.

There is virtually no difference in the undersides of the sexes of alcetas.

Alcetas is a butterfly of southern France, quite localised in Provence, where I have only ever seen it in singles in a few locations. In 2010 I saw 22437 in the Hautes-Alpes in a location where it is not supposed to exist according to the distribution atlas. It seems more common (or less uncommon) in the northern parts of its range, and I have seen it near Lyon and in the Dordogne where on occasions it has been common in certain locations, although the numbers seem to vary year on year.

This species was previously known as Everes alcetas.

ref	sex	observations	alt. m
0791	M	a typical male although the black borders are rather thicker than normal. This photograph shows the blue colour as rather paler than would be expected, perhaps a camera effect.	1000
37218	M	a male, with the tail hardly discernible.	800
53839	M	a male, noticeably smaller and with heavy black borders and a distinct tail.	500
53864	F	a female, adding to the confirmation that there is no blue at all on females and they all have this consistent black-brown ground colour.	500
39217	F	a female, showing some signs of wear, which are far more in evidence on the black ground colour. There appears to be a slight bluish sheen on the upf.	100
9143	F	a female, with constant black-brown colouration.	80
9188	F	a female, slightly fresher than 9143, almost black with no loss of scales as yet.	70
33966	M	a male, roosting in overcast conditions. The greenish tinge is caused by a blade of grass.	180
9099	M	a beautiful very pale ground colour and quite strong marginal marks. The unh marginal lunule in s1c has, atypically, a few orange scales, only visible in close-up.	80
38683	M	a lightly marked male from the foothills of the eastern Pyrénées.	750
53850	M	a male from the same location as 53839 but probably not the same individual.	500
38363	F	a rather more heavily marked female, presumably an altitude effect.	1260
38568	F	a female, near to the upper limit of its altitude range of 1600m.	1350
22437	F	a female, only known for certain because it was seen in flight.	1000