(040521 revised, 040521 created)
Rothschild M, Mummery R
Carotenoids of butterfly models and their mimics (Lep: Papilionidae and Nymphalidae)
Biol. J. Linnean Soc. 28: 359-372(1986).
Carotenoid concentration in model swallowtail butterflies is exceptionally high: it is suggested that they may exert a photo-protective function in species storing nitrophenanthrenes. Carotenoid concentration in the viceroy is also high. Again, it is suggested that this represents a protective mechanism for Lepidoptera feeding on Salix which contains salicin. Such a mechanism would not be required by the monarch storing cardenolides.
Table 1. Carotenoids of model swallowtail and food plants.
Table 2. Carotenoids of mimic swallowtail, Papilio polytes, and food plants.
nitrophenanthrenes: The Common Rose (Pachiopta aristolochiae ) caterpillars eat the leaves of poisonous Aristolochia species to incorporate the nitrophenanthrene toxins into their bodies in order to poison their predators. Several Aristolochia species (notably A. contorta, A. debilis, A. fangchi and A. manshuriensis) have been used in traditional Chinese medicine as anti-rheumatics, as diuretics and in the treatment of oedema. Aristolochic acids are nitrophenanthrene carboxylic acid derivatives that are constituents of these plant species.
the viceroy : Limenitis archippus, kabairo-ichimonji butterfly in Japanese (mimic of Danaus plexippus, habitat: USA)
the monarch: Danaus plexippus, ookabamadara butterfly in Japanese (model of Limenitis archippus, habitat: USA)
Salix: Salix cariolinus is a food plant of viceroy. Viceroy caterpillars eat the leaves of trees in the willow family (Salicaceae) including willows (Salix), and poplars and cottonwoods (Populus). Yanagi in Japanese.
cardenolides: The monarch gets its poison (cardenolide glycosides) when it is a caterpillar, from eating the poisonous milkweed plant (genus Asclepias) while in its larval (caterpillar) stage in order to poison their predators. Milkweed (genus Asclepius) is a common plant that contains cardenolide toxins.
The Visceroy Butterfly: The viceroy and monarch were once thought to exhibit Batesian mimicry, where a harmless species mimics a toxic species. Studies conducted in the early 1990's suggest that the viceroy and the monarch are actually examples of Mullerian mimicry where two equally toxic species mimic each other to the benefit of each.