My old RSNC butterfly book (Thomas, 1986) which had only one species of WW in Britain & Ireland notes that Irish specimens are noticeably greener and English ones. So I guess you don't have to examine the genitalia after all.

Nice shot! There are 2 species of WW in Ireland - sinapis (Wood White, confined to the Burren and south east Galway) and juvernica (Cryptic Wood White). So it's not clear what Jeremy refers to and, to be honest, there has been a LOT of study of various Leptidea since 1986. I know that the experts in this space Dinca, Wiklund, obtained some specimens from Craigavon and their conclusion is that the only way to separate Cryptics from regular WW from Real's WW is a combination of examining the genitalia and, believe it or not, DNA. Can't wait to purchase a portable DNA analyser from "Bugs 'R Us" in 2030Alastair Rae wrote:My old RSNC butterfly book (Thomas, 1986) which had only one species of WW in Britain & Ireland notes that Irish specimens are noticeably greener and English ones. So I guess you don't have to examine the genitalia after all.
Alastair Rae wrote:On a sample size of one ...