About Danaus erippus (Cramer, 1775)
Danaus erippus is a member of Nymphalidae, the largest butterfly family, which contains around 6000 species distributed across most of the world. Like other nymphalids, this species has a reduced pair of forelegs and bright colouration, and the family also includes many well-known butterfly species such as emperors, admirals, tortoiseshells, and fritillaries. D. erippus has a wingspan that reaches around 110 millimetres, or 4.3 inches, with an easily recognizable orange and black wing pattern. Until 2007, this butterfly was classified as a subspecies of Danaus plexippus. The two species are very similar in appearance, but D. erippus typically has an orange trailing edge on its forewings, while this edge is black in D. plexippus. Researchers estimate that the lineages of these two species separated approximately 2 million years ago. For the southern monarch, male butterflies have paler wing colour than female butterflies. This species is found in tropical and subtropical latitudes of South America, occurring mainly in Brazil, Uruguay, Paraguay, Argentina, Bolivia, Chile, and southern Peru. Like D. plexippus, D. erippus uses host plants from the genus Asclepias as larval food; these include A. barjoniifolia, A. boliviensis, and A. curassavica. It also feeds on some non-Asclepias species as larvae, which are Astephanus geminiflorus, Cynanchum boerhaviifolium, Cynanchum atacamense, and Tweedia birostrata.
