Genera, being subjective categories and serving different, in fact opposing, purposes for different people - basically to unite vs. separate (groups of) related species - are impossible to define to everybody's satisfaction. This list with largely 'lumped' genera reflects my current and personal point of view, subject to change, on the generic division of European butterflies. The list follows primarily the arrangement proposed by Kudrna (1996, 2002) with some further modifications based on the morphology of preimaginal stages and genitalia mainly in the Pieridae and Lycaenidae. In the latter case, most striking to many may be the 'lumping' of many 'genera' into a single genus Plebeius - even Polyommatus! Here I am not suggesting anything revolutionary - after painstaking analysis of the genitalia of the Russian species of Polyommatini Gorbunov (2001) found no grounds to uphold any of the arrangements used so far, and included Polyommatus s.l. into Plebeius. Recent DNA analysis (Wiemers 2003) has upheld the untenability of traditional classifications, however without passing any judgement. I find particularly interesting in his analysis that 'Plebeius' s. str. as defined in most recent classifications is found to be paraphyletic, the pylaon-complex clustering with Polyommatus.
My list differs markedly from the generic arrangement in what is presently the most influential popular book on [western] European butterflies, "Butterflies of Britain and Europe" by Tolman & Lewington (1997) and other such popular guides. In this respect, particularly the over-split genera, the current popular books on European butterflies show little improvement over their outdated predecessor, the guide by Higgins & Riley (1970). Yet Tolman & Lewington's "Butterflies of Britain and Europe" is the definite text for most European amateur lepidopterists now and is going to remain so for the forseeable future (though I hope to see the nomenclature updated and streamlined in future editions). For this reason I consider it necessary to provide the names used by Tolman & Lewington (1997) wherever these differ from those in my list. These are found under the respective species, not in the list.
Species. You may find here some controversial species-level taxa, and you have every right to disagree (how gracious of me). In a way I am seeking to upset the well-entrenched illusion that the butterfly fauna of Europe is so well known taxonomically that there is no need to bother with such trivial stuff. Nothing could be further from the truth. For this illusion I blame the interesting psychological phenomenon of interpreting the availability of a hard-cover butterfly guide with lots of colourful pictures and distribution maps as an evidence that the ultimate state of knowledge has been achieved. Yes, European butterflies have been collected and studied for longer than anywhere else, yet there are still many unexplored areas - especially in the East and South-east. This is only part fo the problem : a much more serious deficiency is that even where there is great amount of data, it has not been made sense of properly. In other words, many butterfly groups and 'species' are in need of taxonomic revision. Here I am not even talking about new species to Europe, which are found at irregular intervals. New species to science are being discovered (either described as new taxa or 'upgraded' from subspecies) from Europe at an average rate of about one every two years. Recent additions are Leptidea reali, Plebeius budashkini, P. orphicus, P. andronicus, P. slovacus, P. villai, not to mention the taxa described from the Caucasus. DNA analysis suggests that what we now blissfully regard as the species Plebeius icarus is in fact a genetically heterogeneous group that apparently may contain many species: the genetic distance between sampled populations of 'icarus' from North Africa, Europe and Western Asia is much greater than between sympatric Greek icarus and andronicus ! Another promising example is what popular guides term 'Plebeius idas', which is a morphologically very diverse assemblage of taxa some of which in addition differ markedly in their habitat type and host plant preferences. I would not be surprised if there actually are up to 4 or 5 species inside 'idas' in Europe alone. Of course, taxomonic progress is a two-way street : changes are happening in the other, 'downward', direction too, with taxa which have been accepted or at least described as species being demoted to lower rank or synonymized. The bottom line: taxonomy is a dynamic field and there is much research to be done on European butterflies before one can dismiss their taxonomic study as a mere hobby on a par with stamp collecting without appearing vastly ignorant, presumptuous or both. For more on this, see my thoughts on collecting vs. photographing butterflies.
Subspecies. Here I have tried to reduce the use of subspecific names to a minimum. The subspecies category in butterfly taxonomy and systematics is much-abused in Europe while there is insufficient understanding of the nature of what are usually deemed to be 'subspecific' differences. Furthermore, these differences should be evaluated against the total variation found in the species, but this is only rarely done. While some recognized local 'subspecies' are mentioned in the respective species accounts, in most cases I consider these to be so poorly defined as to be of little to no real taxonomic value.