Species account

Orange Høsommerfugl (Colias croceus)    Geoffroy (1785)
   Hvidvinger (Pieridae) [Sommerfugle]    CLYE    24847
Clouded Yellow (gb)   Colias Común (es)   Rödgul Höfjäril (se)  
Subspecies
Form: deserticola
Verity (1909).
Form: helice
Hübner (1803) - pale females resembling C. hyale (Gul Høsommerfugl).
Form: helicina
Oberthür (1880).
Form: mediterranea
Stauder (1913).
Measurements:
WS: 44-50mm
Generations:
1-3
Flight period:
JFMAMJJASOND 
Scan
Identification:
Deep orange color above makes it characteristic in the Nordic region. Females show pale spots in the black-bordered tips and margins of both upper wings; the male is solid black. Compared to hyale [Gul Høsommerfugl] the black rim covering the forewing tip above is running down along the outer margin in a very solid band, reaching the inner margin, running past the anal corner.

The underside of the forewing shows a deep yellow-orange center resembling the upperwing color, and much warmer than on similar hyale [Gul Høsommerfugl]. The hindwing is deep yellow with a greenish cast, and similar to hyale shows a black spot on the forewing and a white spot centrally on the hindwing. This seems like being double-red-encircled, giving it a more pronounced appearance than on hyale [variable].

Never shows the upperside at rest.

The wing tip of croceus is supposed to be narrower than on hyale [likely variable].
Similar species:
Life stages:
Distribution:
N Africa, S and C Europe, Middle East to W Asia.
Habitat:
In Nordic region, mostly coastal areas. Flower-rich fields.
Behavior:
A strong flyer. In the Mediterranean region it flies all year.
Host plants:
Humle-Sneglebælg (Medicago lupulina) [Black Medick ~ Humlelusern]
Rød-Kløver (Trifolium pratense) [Red Clover ~ Trébol Rojo ~ Rödklöver]
Lucerne (Medicago sativa) [Alfalfa ~ Lucerna ~ Foderlusern]
Almindelig Kællingetand (Lotus corniculatus) [Bird's-foot Trefoil ~ Loto Corniculado ~ Käringtand]
Muse-Vikke (Vicia cracca) [Tufted Vetch ~ Arveja Silvestre ~ Kråkvicker]
Rundbælg (vulneraria) [Common Kidneyvetch ~ Vulneraria ~ Getväppling]
Foder-Esparsette (Onobrychis viciifolia) [Common Sainfoin ~ Esparceta ~Esparsett]
and other plants of the pea-family (Fabaceae).

Feeding plants:
The same as many of the host plants.
Endemic:
Status
In Denmark and Nordic region a rare southern singleton visitor, mostly in August. The most widespread Colias species in Europe.
Comment:
Large influxes in Denmark were seen in 2009 and 2018, expecting 2027 to show the next...

Number of generations depends on local conditions.
Clouded Yellow 3365    (8 photos)
2025-08-13    Kalvebod Fælled, Denmark

Imago Par
Granatsø. Mating.
Discovered the first animal just as I arrived. Clearly orange in the wing, there was no doubt about the species. It continued to explore a stretch of 200 meters of dry meadow, frenetically moving forth and back in search of a mate. I thought it was a male looking for a female, but as the in-flight photos show, it was the female who was all up and running here.

At a point it stopped coming back and I thought it was gone or had found a perch in the short grass. I checked the ground in the direction it had last flown, and reached the end without seeing it. The obvious thought was that it had continued, and I too decided to continue with what I came for originally: Dragonflies. But then as I started to go back, it flew up. An orange flash. But it was different this time. Looked more clumpsy, and then all the yellow hanging below it. Maybe it had been different animals flying forth and back, and finally they found each other. The male, without white spots in the forewing, took the lead slow-carrying both of them to a likely safer spot than where I just flushed them from. He soon dropped to the ground and they continued their mating pleasures. This was around 13:15. I got my photos (or at least photos as good as my old camera allows me to have), and then I continued to look for dragonflies. 45 minutes later I decided to go back, just to see if they were still in action. And they were. Same spot, same moveless position with the male being on top and the female hanging head-down. I then decided to leave this locality and visited the rest of the spots I had planned for this afternoon. Two hours later, on my way home, I decided to make a quick visit, and they were still there. I left them at 16:50.

I don't know much about the mating strategies of these butterflies, but it seems to be an extremely long process I had just witnessed. If they are still there tomorrow, I'm buying icecream for everyone who reads this - Free delivery, where-ever you are..!

In a short-grassed dry field with mainly clover [kløver], Yarrow [Røllike] and Bird's-foot Trefoil [Kællingetand].
In photo 2 followed by a Small Heath (Coenonympha pamphilus) [Okkergul Randøje].

Same as 3366.

Rare
Clouded Yellow 3366    (1 photos)
2025-08-14    Kalvebod Fælled, Denmark

Imago Han
Granatsø. Same as 3365.

Still present this afternoon with the same behavior flying forth and back along the same stretch. Today, however, it chose to visit several flowers during the transects, which it didn't do yesterday. Then, probably very focused on finding a mate, and less so today with the compass recently and well-adjusted after three and a half hours [and more] of active duty fulfilled!

Thomas Larsen got photos of the upperside deciding the sex, and my photos show that it is the same male as yesterday.

Here on Autumn Hawkbit [Høst-Borst].

Rare