Southern Bulgaria

[nik_s]

Excellent report, with great photos and some spectacular species indeed!

Some notes on the Phalakron/Common Blue discussion:

1. There is a well established difference in genitalia (both male and female) between the Phalakron and the Common Blue, including specimens from the same site.
2. As Mikhail noted in a previous post, the studied DNA sequences of the two species are virtually identical. Note that this does not mean their entire DNA is identical - the studies cover only two very short "pieces" of the entire DNA.

It is possible (although uncommon) to have two different but closely related species that share these two DNA sequences. My (personal) opinion is that until the matter is resolved by further studies, they should be considered separate species.

My experience with this species is that some (fresh) individuals are easy to identify; size however is not a reliable feature. There are some very large Common Blues, as well as some small Phalakron Blues so the wing sizes overlap significantly. In genitalia on the other hand there is no overlap (Kolev Z., 2005, Nota lepid. 28: 35-48) so for unambiguous identification genitalia should always be checked.

Finally, the Phalakron Blue is a montane species that flies only at high altitudes (above 1400m), most commonly above the tree line. Given its habitat preferences, I'd say it's highly unlikely to encounter it in the East Rodopi. In Bulgaria, it can be found in the Pirin and Slavyanka (Alibotush) Mts.

Cheers,

Nikolay

[Paul Wetton]

Hi Nikolay

Many thanks for clearing up the situation with the Phalakron Blue. I am sure you are correct and the butterflies I saw in the Rhodopi Mountains were likely to be Common Blues although I have never seen such differences in size and colour with Common Blue in the UK.
Do Common Blue males in Bulgaria show a brown underside ground colour in the summer brood as they do in the UK. I just wonder because the Phalakron Blue has a pale and grey underside ground colour which would help to distinguish the two species at least whilst the summer brood of Common Blue is flying.
Maybe there is more to the situation than meets the eye at the sub species level.

Thanks again.

[nik_s]

Hi Paul,

Do Common Blue males in Bulgaria show a brown underside ground colour in the summer brood as they do in the UK. I just wonder because the Phalakron Blue has a pale and grey underside ground colour which would help to distinguish the two species at least whilst the summer brood of Common Blue is flying.

Yes, summer brood Common Blue males have on the average a more yellowish underside ground colour and the blue basal suffusion is reduced with respect to the spring brood Common Blues (and to Phalakron Blue males). The problem is that the variability of both species is so significant that the identification of many specimens by external characters (including size, colour, etc.) is uncertain. Things become more difficult for individuals that are worn-out even slightly.

Of course, external characters can be helpful to some extent. This is a very difficult species, but I have found that identifying it gets somewhat easier with experience. I strongly recommend Zdravko Kolev's article http://www.soceurlep.eu/tl_files/nota/b ... lev_02.pdf for an in-depth discussion of all characters that can be used for identification. It would also be better to start the search at a proven location.

Regards,

Nikolay

[Mikhail]

Nikolay
Many thanks for providing a link to Kolev"s paper: I had wanted to see that. It's most illuminating.

M.

[Paul Wetton]

Yes thanks Nikolay, it looks very interesting but I'll have to wait until I return home from work before having a good read of it.