Danaus (genus) - Taxonomy

Taxonomy

Following the review of Smith et al. (2005), 12 species are provisionally accepted based on morphological, mtDNA 12S rRNA and cytochrome c oxidase subunit I, and nuclear DNA 18S rRNA and EF1 subunit α sequence data:

• Danaus affinis (Fabricius, 1775) – Malay Tiger
• Danaus chrysippus (Linnaeus, 1758) – Plain Tiger, Common Tiger, or African Queen
• Danaus cleophile (Godart, 1819) – Jamaican Monarch
• Danaus dorippus (Klug, 1845) – Dorippus Tiger (formerly included in D. chrysippus)
• Danaus eresimus (Cramer, 1777) – Soldier, or Tropical Queen, includes D. plexaure
• Danaus erippus (Cramer, 1775) – Southern Monarch
• Danaus genutia (Cramer, 1779) – Common Tiger, Indian Monarch, or Orange Tiger
• Danaus gilippus (Cramer, 1775) – Queen
• Danaus ismare (Cramer, 1780) – Ismare Tiger
• Danaus melanippus (Cramer, 1777) – White Tiger, Common Tiger, or Eastern Common Tiger
• Danaus petilia (Stoll, 1790) – Lesser Wanderer
• Danaus plexippus (Linnaeus, 1758) – Monarch or Wanderer

This genus was formerly split into the subgenera Danaus, Salatura, and Anosia, but this arrangement has been abolished. While the first (the 2-3 monarch butterflies) and Salatura (species ismare, genutia, affinis and melanippus) do indeed seem to be clades, the relationship of these to the other species, especially the puzzling D. dorippus, is not clear.

Hybridization producing fertile offspring is known to occur between some species, confounding mtDNA data; this seems to be especially true in the case of D. dorippus (Smith et al. 2005). In addition, male-killing Spiroplasma infection has been shown in D. chrysippus and probably also occurs in other species (Jiggins et al. 2000); the consequences for speciation and evolution are probably similar to those observed in infection with male-killing strains of the better-researched Wolbachia bacteria.