Zerynthia cassandra (Geyer, 1828) or Zerynthia demnosia (Boisduval, 1828)? Which one is the correct name according to the International Commission of Zoological Nomenclature?

The author succeeds in clarifying the taxonomic and nomenclatural uncertainties within the species complex of Zerynthia polyxena from Italy. Respecting the specific state of the Italian Festoon as proposed by Dapporto (2010), its species name must be demnosia Boisduval, 1828 with the type locality ‘San Giórgio a Colónica’ (Dapporto, 2010), which corresponds to Florence in the sense of Mann (1844). The name cassandra Geyer, 1828 has to be considered as a younger synonym of polyxena [Denis & Schiffermüller], 1775 and is not available as a species name for the Italian Festoon. The substitution of the species name cassandra sensu Dapporto (2010) by demnosia Boisduval, 1828 allows furthermore the use of the name cassandra Geyer, 1828, as a forma to denote individual and local forms with strong patterning of Zerynthia polyxena in southern Europe including the populations of southern France and eastern Liguria