From Wildlife Extra:
New butterfly species discovered in Ireland
Discovery of New Wood White Species – By kind permission of Butterfly Conservation Ireland & Jesmond Harding
July 2011. Butterfly Conservation Ireland are reporting that, following a new study of wood white butterflies in Ireland and other parts of Europe, a new ‘cryptic’ species of Wood white has been identified by DNA tests.
In the late 1980s a new European species of Wood white butterfly was discovered when Leptidea sinapis (Wood white) was found to “hide” a cryptic species, Leptidea reali, or Réal’s Wood White. The 2 species are separable based on their genitalia. Both species live in the same geographical area, the Palaearctic: region comprising Eurasia north of the Himalayas, North Africa and the temperate part of the Arabian Peninsula, and the distribution of reali is almost as wide as that of sinapis. Previous studies of the behavioural and ecological aspects of L. sinapis and L. reali show that
Females only accept as mates males of their own species,
Only small ecological differences exist (larval foodplant preferences),
Differing niche preferences of the 2 species is not caused by their being separate species
Differences in phenology (e.g. when a larva pupates, when the adult flies etc) and voltinism (number of generations in a year) are mostly caused by the effect on the butterfly of its environment
The female tendency to mate is influenced by its response to environmental conditions.
More about this is here.