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Species Danaus plexippus - Monarch - Hodges#4614

Monarch - Danaus plexippus - male Monarch Butterfly - Danaus plexippus - male - female Monarch - Danaus plexippus - female Danaus plexippus - female Monarch - Danaus plexippus Butterfly - Danaus plexippus Queens butterfly? - Danaus plexippus - male Monarch in August in Colorado - Danaus plexippus - female
Show images of: caterpillars · adults · both
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Lepidoptera (Butterflies and Moths)
Superfamily Papilionoidea (Butterflies and Skippers)
Family Nymphalidae (Brush-footed Butterflies)
Subfamily Danainae (Milkweed Butterflies & Glasswings)
Tribe Danaini (Milkweed Butterflies)
Genus Danaus
Species plexippus (Monarch - Hodges#4614)
Hodges Number
Other Common Names
Milkweed Butterfly
Synonyms and other taxonomic changes
Danaus plexippus (Linnaeus, 1758)
Papilio plexippus Linnaeus 1758
Wingspan 8.6-10.5 cm
ADULT: large, with conspicuous black veins on orange wings.
Monarchs often show a distinctive gliding flight with their wings held tilted upward in a dihedral (V shape).
Males have scent-scale patches on hindwings, prominent when wings are open, and just possible to see when wings are folded.

LARVA: entire length has alternating black, white, and yellow bands; front and hind ends have a pair of long black filaments projecting diagonally upward
Much of temperate North America into tropics and much of South America. Also some islands in Pacific, Australia (introduced?). Highly migratory.
Open areas with flowers, hostplants
March through fall in North America; all year in tropics.
Adults take nectar from a variety of flowers.
The caterpillars feed on plants in the Milkweed family (Asclepiadaceae [or Apocynaceae in part]), primarily Milkweeds (Asclepias), but also other genera including Calotropis, Cynanchum, Gonolobus, Sarcostemma, etc.
Life Cycle
The adults make mass migrations from August-October, flying to hibernate along the California coast and in central Mexico.
At the wintering sites in Mexico, the butterflies roost in trees and form huge aggregations that may have millions of individuals.
They leave for the north in the spring, and females lay eggs along the way.

The females lay eggs singly on the leaves of the milkweeds (Asclepias); caterpillars eat the leaves and flowers.

An egg


and one that won't make it:

The chrysalis is light green, except for when the butterfly is about to emerge

female vs male:

Chrysalis just before emergence

Freshly emerged butterfly

and some don't make it:
There are extensive accounts of Monarch migration and ecology in technical and popular literature.
See Also
Members of the public often mistake the unrelated Viceroy (below) for a Monarch, but the Viceroy is much smaller and has a black band across the hindwing.
See comparison of Monarch (1) and Viceroy (2) hindwings here:

The related Queen lacks black veins on the forewing and has darker/browner wings, and the Soldier has darker/browner wings.
Print References
Glassberg (1)
Brock and Kaufman (2)
Scott (3)
Allen (4)
Rea (5)
Koch, R.L., R.C. Venette, and W.D. Hutchison. 2005. Influence of alternate prey on predation of monarch butterfly (Lepidoptera: Nymphalidae) larvae by the multicolored Asian lady beetle (Coleoptera: Coccinellidae) Environmental Entomology.‚ÄČ34(2): 410-416.
Works Cited
1.Butterflies Through Binoculars: The East
Jeffrey Glassberg. 1999. Oxford University Press.
2.Butterflies of North America (Kaufman Focus Guides)
Jim P. Brock, Kenn Kaufman. 2003. Houghton Mifflin Co.
3.The Butterflies of North America: A Natural History and Field Guide
James A. Scott. 1992. Stanford University Press.
4.The Butterflies of West Virginia and Their Caterpillars
Thomas J. Allen. 1998. University of Pittsburgh Press.
5.Milkweed, Monarchs and More: A Field Guide to the Invertebrate Community in the Milkweed Patch
Ba Rea, Karen Oberhauser, Michael Quinn. 2003. Bas Relief Publishing Group.
6.Butterflies of North America