Pale Clouded Yellow (Colias hyale) and Bergers Clouded Yellow (Colias alfacariensis)
2009 photos highlighted in yellow. Click on any photo to go to an enlarged picture, or simply scroll down the page.
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| 0310_male_Var_4May06 - alfacariensis | 10035_pair_Var_25Apr08 - alfacariensis | 10060_male_Var_25Apr08 - alfacariensis |
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| 0480_female_Var_9May06 - alfacariensis | 3985_female_Isere_16Aug06 - alfacariensis | 16726_pair_Var_25Jun09 - alfacariensis |
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| 17691_male_Hautes Alpes_09Jul09 - hyale | 2765_male_Italy_17Jul06 - hyale | 8505_male_Alpes de Haute Provence_24Jul07 - hyale |
I have put hyale and alfacariensis on the same page as they are almost impossible to tell apart by external characteristics, and the existence of alfacariensis as a separate species was not confirmed until around 1947. Many illustrations and photos labelled as hyale in books prior to that were in fact alfacariensis. My experience is that most specimens which could be either, turn out to be alfacariensis. Hyale seems to be quite scarce in France, and I am not sure this was always the case, so maybe it is diminishing, but identification problems probably preclude any such conclusions. The larvae are different, I understand.
Both are clearly a paler yellow than the Clouded Yellow (C. crocea), so confusion there is almost impossible, except with helice females. Alfacariensis is generally a stronger lemon yellow, and hyale rather paler, hence the name, although hyale's "pale" name came coincidentally from its comparison with crocea, not alfacariensis. It is probably true that any individual that appears bright lemon yellow is almost certainly (male) alfacariensis, but the reverse is not necessarily true, and this pointer may be subject to considerable regional and altitude variation.
The most reliable (if any are) external characteristic is that alfacariensis has a slightly more rounded forewing outer margin and hyale is straighter with a more pointed wing tip (apex). If either the margin or apex are rounded, it is alfacariensis, but I'm not sure the converse is always true. The degree of curvature seems to me to be very variable, as evidenced by the photos above, 0310 being extremely rounded and others here being either quite straight-edged and/or quite pointed at the apex. Photographs can be misleading if not exactly at 90 degrees to the plane of the insect. The upperside uph discal spots are a different colour, but this doesn’t help (unless you are prepared to catch and examine specimens, which I am not) as they do not settle with open wings, although occasionally a quick photo of courtship might catch this.
It is easy to separate them in Var: hyale does not occur in Var, according to Lafranchis, and I have not seen any concrete evidence to disbelieve this. I have, however, been looking closely at the forewing margins and apices of specimens in northern Var in 2008 and they are decidedly less rounded than those seen in the south of the département. Northern Var is a comparative wilderness compared to the relatively highly populated south of Var (the A8 autoroute makes a good dividing line), and I suspect somewhat under-recorded. I intend to study this further in 2009 with reliable photos.
0310: I am reasonably confident that this is a male alfacariensis as the forewing outer margin is VERY curved and the apex not particularly pointed, even though the ground colour is quite a pale yellow. Altitude 340m.
10035: the male of a mating pair of alfacariensis. A slight forewing curvature, but very bright yellow, despite the widespread darker speckling of scales. Note the female is hanging off the edge with no foothold. No manners, this male! Altitude 185m.
10060: a male alfacariensis, a slight curvature even though the apex appears pointed (this may be exaggerated by the camera angle). A very bright yellow ground colour, especially in the unf apical area, with a couple of yellow splashes below. Altitude 185m.
0480: a very pale female alfacariensis. I originally thought it might be crocea as the upf black apical area seemed to show through quite low, but I feel it must be a female alfacariensis even though the forewing outer margin looks straight, the apex is quite rounded, though. Altitude 185m.
3985: a female alfacariensis, the ground colour is a strong yellow and the curvature of the forewing outer margin can be seen clearly even allowing for the camera angle. The big question is not alfacariensis vs. hyale, but whether it is a female Clouded Yellow (C. crocea) of the form helice: the extent of the upf black apical margin can be seen quite clearly and I feel this is not sufficiently wide for crocea, and the unf apical yellow is limited and there is not unf yellow flush in the cell area. However, I wouldn't bet my house on it. The white area is beautifully clean and strong. It really is a very appealing butterfly. Altitude approx 1300m.
16726: a mating pair of alfacariensis. The male is probably the one on the right. Altitude 220m.
17691: I believe this to be a male hyale for much the same reasons as 2765 below. It was seen in the Hautes Alpes where hyale is known to occur. Thin evidence for all three putative hyale on this page, but there is a general consensus that hyale and alfacariensis cannot be reliably identified from the external features visible from an underside-only view. Altitude 2100m.
2765: I believe this is a male hyale as the forewing outer margin is quite straight and the apex is maybe just about pointed enough for hyale. The ground colour is a pale lemon yellow indicating hyale. It was seen in northern Italy, where hyale does occur. Altitude approx 600m.
8505: I believe this to be a male hyale because of the colouring and the evident straight margin and pointed wingtip. However, the butterfly was in motion, so this may not be conclusive.
0310_male_Var_4May06 - alfacariensis
10035_pair_Var_25Apr08 - alfacariensis
10060_male_Var_25Apr08 - alfacariensis
0480_female_Var_9May06 - alfacariensis
3985_female_Isere_16Aug06 - alfacariensis
16726_pair_Var_25Jun09 - alfacariensis
17691_male_Hautes Alpes_09Jul09 - hyale
2765_male_Italy_17Jul06 - hyale
8505_male_Alpes de Haute Provence_24Jul07 - hyale
