Danaida plexippus (Linnaeus)

Swezey, O. H., 1942, Lepidoptera, Butterflies of Guam, Insects of Guam I, Honolulu, Hawaii: Bernice P. Biship Museum, pp. 31-38 : 32

2. Danaida plexippus (Linnaeus) .

Papilio plexippus Linnaeus , Syst. Nat., 10th ed., 471, 1758 .

Danaida plexippus (Linnaeus) Walker, Ent. Mo. Mag. 25: 187, 1914.

Poulton, Ent. Soc. London, Trans., 453, 1928; B. P. Bishop Mus., Bull. 114: 299, (1934) 1935.

Ritidian Pt. , April 15, 22, Bryan; Mt. Alifan, May 4, 26, June 19, Swezey ; Fadian, Sept. 18, Swezey ; Piti, Sept. 17, Swezey ; Orote Peninsula, Sept. 27, Swezey ; Yigo, Oct. 21, Swezey . The caterpillars were most numerous in a weedyclearingonMt. Alifan . TODO

This is the widespread American species known as the monarch or milkweed butterfly. There has been confusion in literature because various names have been used for it, particularly archippus Fabricius and plexippus Linnaeus. It has finally been considered that plexippus Linnaeus is the correct name as is e.xfplainedby N. D. Riley (Ent. Soc. London, Trans., 454, 455, 1928). Where the name plexippus has been used for the related Oriental butterfly, genutia Cramer should be used.

The monarch has spread from America across the Pacific to the various island groups following the spread of the milkweed ( Asclepias curassavica ) on which its caterpillars feed. They feed on any species of Asclepias or related plants, but A. curassavica has been the particular species which in historical times spread over the Pacific area. This weed is abundant in Guam, along roadsides and in waste land and fields, sometimes forming dense stands almost acres in extent. Correspondingly the butterfly is abundant. As it is a common species, we paid little attention to it.