Colias hyale and Colias alfacariensis

[nomad]

I believe the top specimen with rounded wings may be C. alfacariensis? Images taken by Me. Bristol Museum collections. 

 


 

[bobw]

Looks about right to me.  I'm just off to the Natural History Museum where I'm currently recurating these two species (and have been for a few weeks).  I've probably looked at about 5,000 of them in the last few weeks and had to try to split the species as it wasn't known they were separate when most of the collection was compiled.  Having looked at so many I reckon I'm up to about 95% accurate determination for males and 80% for females; I would say that of the European specimens about 90% are alfacariensis.

Bob

[nomad]

Thanks Bob. That's a lot of specimens to sort out. Astonishing that the British collectors were at taking another species among their Colias hyale and Colias alfacariensis was not described until 1948. The two specimens shown here were taken at Swanage in Dorset by Pitman (Roy?) in 1945.
 
Do you know why Colias hyale and I suspect Colias alfacariensis after being fairly frequent migrants, have become two of the rarest visitors to our shores and I why they rarely visit Britain today?

[Deleted]

They have been cropping up on the Isle of Portland frequently over the last few years, well hyale at least but only in 2's and 3's

[Alexander]

Nov 23, 2017 7:14:45 GMT nomad said:

I believe the top specimen with rounded wings may be C. alfacariensis? Images taken by Me. Bristol Museum collections. 

You are right to 95%... Top photo: male Colias alfacariensis. Lower: male Colias hyale.
 At least in Ukraine they look exactly like that.

Attachments:

[nomad]

Nov 23, 2017 17:49:16 GMT @dp1965 said:

They have been cropping up on the Isle of Portland frequently over the last few years, well hyale at least but only in 2's and 3's

Very nice series of specimens Alexander and thanks for the further information. 2,000 hyale were recorded in Britain in 1900 and hundreds  between 1945-1949. There must be a good reason why this species does not move north into the UK anymore except  very occasionally and then only 2 or 3 and not every year.  

[Deleted]

Most of my British examples are from the 1940's

[nomad]

While we are on the subject of Colias, if the white female form of Colias croceus is helice what is the lovely lemon form called?

[nomad]

Here is the Colias croceus f helice together with the lemon form, name? with a typical female. British specimens. Bristol Museum coll. 



 

[wollastoni]

Nov 24, 2017 11:50:32 GMT nomad said:

together with the lemon form, name?

I've always called this yellow form "helicina". I will let specialists like bobw confirm.

[bobw]

I have to admit I don't have the time to get involved with infrasubspecific forms and purely concentrate on available names.  However, like wollastoni I've always considered the yellowish female form to be helicina Oberthūr, 1881.

Bob

[nomad]

Thank you Olivier and Bob.