My first ever sighting of ilia was in the Pyrénées in 2005 and it felt like a privilege to be allowed to see this magnificent beast swooping and gliding. It was the orange form clytie, not uncommon in the south of France.

Given that the blue-purple colour flashes on and off as it moves, I have found it difficult to determine exactly how clytie differs from the nominate form in the male in particular. The books do not appear to make it clear whether clytie has the blue-purple colouring or not, and if it does, to what extent, and in this case, what actually differentiates the two forms. It seems to me, as stated in H&R, that the differentiating factor is that the upf and uph discal bands are white in the nominate ilia and orange or pale orange in clytie, but clytie can have the purple sheen albeit to an apparently lesser extent.

Ilia has a habit of gliding at a metre or so above the ground, settling from time to time at the edge of trees at around 3m above the ground. It is normally, almost always, found in the vicinity of water. 2009 was an exceptional year for my sightings of ilia, as was 2010, but I could not say whether that was because ilia was enjoying a bumper year or whether I was just fortunate to be in the right places at the right times. At the location where I saw 18328, there was also a single iris and a Camberwell Beauty (Nymphalis antiopa) among the 56 species (seen over two days) flying at this small riverside spot.

observations

a male ilia of the nominate form. The four photographs are of the same individual (17898 is the underside) and demonstrate how the colour changes as they move, in this case walking around puddling and opening and closing its wings as it did so; the effect is a dazzling flashing colour that really has to be seen to be believed, and only a video of ilia (or iris) can really do it justice in this respect. An unforgettable experience.

a male of the form clytie, taken at the particular angle when no purple was visible. Other photographs of the same individual show the purple sheen, thus confirming that it is a male.

a male, of the form clytie, showing the semi-purple appearance, halfway between the orange appearance and the full purple sheen.

a male, of the nominate form.

ilia of the form clytie, which I am assuming to be male based on its taking salts from the ground. I did not record at the time whether any blue-purple colour was visible which would have confirmed male. The body shape is not conclusive in determining the sex of 18328, but I feel that the absence of scalloping on the hindwing and its behaviour strongly suggest male.

a male underside of the form clytie.

a male underside of the form clytie.

the underside of the nominate form, probably the same individual as 17889. The upperside colouring and markings (of ilia and clytie) seem to be reflected in the undersides, albeit to a lesser degree.

17889_male_Isère_11Jul09

17890_male_Isère_11Jul09

17892_male_Isère_11Jul09

17901_male_Isère_11Jul09