Recent years have seen enormous developments in the taxonomy and nomenclature of butterflies. This is in large part due to the increasing use of biochemical and molecular (rather than merely morphological) methods of establishing phylogeny.

The scientific names of animals are governed by the International Code of Zoological Nomenclature. This defines such things as the validity of taxa, the formal grammar and syntax of names and the rules of precedence in cases of conflict. The application of the Code is overseen and where necessary arbitrated by the International Commission on Zoological Nomenclature (ICZN). Within the constraints imposed by the Code, there is a great deal of choice open to biologists, not only in the question of particular names but also in that of how broadly or narrowly to define a taxon. Valid taxa should be cladal - that is, all members of the taxon should be more closely related to each other, in terms of most recent common ancestor, than to any organism outside the taxon. In reality, given the fact of hybridisation and back-crossing, even this fundamental criterion is probably impossible to apply perfectly, but it works broadly for animals and is essentially a factual constraint. Deciding the actual boundary lines around subspecies, species, genera, tribes, subfamilies, families, superfamilies &c. is, however, a matter of choice, predicated on utility, clarity, and to a certain degree, personal aesthetic preference. Different authors draw these lines in different places and there is no universally agreed central authority responsible for dictating which should be regarded as 'right'.

Names may thus change for one (or more) of three reasons: revised application of the rules of nomenclature to existing names (precedence of older names, discovery of historical errors in type specimens, changes of gender to match genus, &c.); discovery of new biological facts; revised choices regarding the lumping or splitting of valid  taxa.

Amateurs like me have no choice but to choose an authority or authorities to follow. Where possible, I look at original research papers when I make decisions, and I try to reflect recent thinking, but I lack both access to all the research and the time to consider it in detail. The names I have adopted in this website will necessarily be different in particular cases from those used in other websites and in books. I include a complete taxonomic checklist HERE, with comments giving some of the history and alternative names, which I hope will aid clarity. Please recognise this is not an authoritative source.