yep Pete, its Holly Blue, your turn again. Think is one of the highest fliers of all Blue butterflies, but could be wrong. I have seen them fly over very tall trees before
Sorry folks I've only just read this thread, but the Green Hairstreak doesn't produce green pigment. It has a diffraction lattice which only has short range order. This is why it gives a uniform green and the colour doesn't change much over different angles in the way that many blue butterflies do. If you want to read the details yourself then get a copy of this paper or I can explain further if you want ; )
R. Morris, Iridescence from diffraction structures in the wing scales of Callophrys rubi, the Green Hairstreak, Journal of Entomology, 1975, vol 49, p149-154.
We obviously need some tougher questions if this is to be a 'daily quiz' rather than a rapid-fire exchange of riddles!! And you're just the man for the job, Felix.