Hello again, Colin.
Regarding differentiation between Chalk-hill and Provence Chalk-hill.
I know why you're asking the question, and I too am confronted with the same problem.
Both of us (me in the Bouches du Rhone and you in the Alpes Maritimes) have potentially co-habitating colonies of coridon and hispana.
I don't feel that illustrations in the text books help me very much. The tenuous descriptions in the text of the differences between the two species are hardly corroborated by the photos. In T. Lafranchis 'Papillons de France', coridon is described as having a "bordure grise large et pleine", and hispana is described as having a "bordure grise mince ou discontinue", whereas when you look at the 2 photos, you could say that they are exactly the same insect
In a thread a while back, someone pointed out to me (and quite logically so) that I should look again in the same place in the Spring, that the only way to be sure which colonies you have around you, is to try and locate individuals during the earlier flight period as they are necessarily hispana.
hispana flies potentially from mid April to late June, with a diapause, followed by start August to start October, whereas coridon flies end June to end September.
This seems to have worked for me and I think I have been able to distinguish 3 hispana sites from 1 coridon site purely by flight periods.
This is not entirely satisfactory or fulfilling, but until my identification skills improve, it will have to do.
Here is a photo of an injured individual, which according to my flight time theory, should be coridon.
Cheers, Chris
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