Identify Monarch Butterfly: 5 Checks and 4 Look-Alikes

A monarch is a large orange butterfly with bold black veins and a thick black border filled with small white dots. Five checks confirm it:

• Size. Wingspan 3.5 to 4 inches (9-10 cm), about the size of a playing card (Xerces Society); the National Wildlife Federation says almost 5 inches across.
• Veins. Bold black veins across bright orange wings, darker on the upper side than on queens and soldiers (Okies for Monarchs).
• White dots. Neat rows of small white dots that always fall inside the black areas, never in the orange (Xerces Society).
• No hindwing bar. There is no black line crossing the hindwing; that line marks a viceroy.
• Flight. A slow, steady flight with flaps alternating with glides (Xerces); NWF calls it sailing.

The body is black with white dots on the head and thorax and white speckles on the abdomen (Xerces Society).

• Viceroy (*Limenitis archippus*): slightly smaller, with a black line across each hindwing that Okies for Monarchs likens to a smile drawn across the wings; quicker, fluttery flight (Xerces). Wikipedia calls it a Müllerian mimic that is markedly smaller.
• Queen (*Danaus gilippus*): wingspan 2.5 to 3.5 inches, a deeper, browner orange, faint or no black veining on the upper side, and white spots in the orange as well as the black (NWF, Xerces). Mostly southern US, Mexico and Central America (NWF).
• Soldier (*Danaus eresimus*): like the queen, deep reddish-brown with little black veining and white spots in both orange and black areas, with a brown abdomen (Xerces).
• Painted lady: 2 to 2.9 inches, with complex orange patterns and no black veining; the black and white border blends into the orange instead of forming a clean edge (NWF).
• Gulf fritillary: narrower, longer wings with black spots rather than borders, shiny silver spots underneath, and fast, erratic flight (Xerces).

The quickest single test: white dots inside the orange mean it is not a monarch.

Look at the hindwings from above. Males have a small black spot on a vein of each hindwing, which holds scent scales used in courtship; females lack the spots, look darker orange and have thicker black veins (Monarch Joint Venture, Wikipedia). Xerces adds that males have claspers at the tip of the abdomen.

• Egg: about 1.2 mm tall, off-white or yellow with lengthwise ridges, laid singly on the underside of milkweed leaves; hatches in 3 to 5 days (Monarch Joint Venture, Okies for Monarchs).
• Caterpillar: bold yellow, black and white bands, two pairs of black tentacles (a longer pair near the head, a shorter pair near the rear), up to about 1.75 inches (NWF) and 4-5 cm (Xerces). It spends about 9 to 14 days feeding in summer (Monarch Joint Venture).
• Caterpillar look-alikes: queen and soldier caterpillars also eat milkweed but have three pairs of tentacles; black swallowtail caterpillars have no tentacles, more green, and feed on dill, fennel, parsley or rue (Xerces, NWF).
• Chrysalis: jade green with metallic gold dots, 1 to 1.75 inches long, turning clear just before the butterfly emerges (Xerces); it lasts 8 to 15 days in normal summer conditions (Monarch Joint Venture).

See caterpillar identification for other striped caterpillars.

In North America, effectively yes. The National Wildlife Federation says one subspecies, *Danaus plexippus plexippus*, is found across North America, and a second, non-migratory subspecies, *D. p. megalippe*, occurs from Florida and Georgia southward. Worldwide, Wikipedia lists six recognised subspecies and two colour morphs, including a white form (*nivosus*) common on Oahu, Hawaii, and rare elsewhere.

People also speak of the eastern and western monarchs, which are migratory populations rather than separate species: the US Forest Service says monarchs fly 2,000 to 3,000 miles to overwintering sites in Mexico, and Xerces notes a second wintering area on the California coast.

Photograph the upper side with wings open to show the veins, dots and any hindwing bar, then the underside if it lands with wings closed. For sexing, you need the hindwings clearly. In InsectLens, a viceroy or queen will show up in the suggestions if the hindwing line or the dot placement says so, which is the check to confirm by eye.

Research and drafting for this page used AI assistance. Every figure, date and quotation was then checked line by line against the sources listed at the bottom of the page, each of which was opened while writing. Nothing here is a diagnosis or a treatment plan; if a bite, sting or rash worries you, or anyone has trouble breathing or swelling of the face or throat, get medical care straight away.