MONARCH BUTTERFLY

(Danaus plexippus), a familiar member of the milkweed butterfly family Danaidae (order Lepidoptera), distributed throughout the world but concentrated mainly in North, Central, and South America. The monarch's wingspan averages 90 to 100 millimetres (about 4 inches). The distinctive coloration of the reddish-brown wings, marked by black veins and a black border with two rows of spots, warns predators of the insect's bad taste. The edible viceroy butterfly (see brush-footed butterfly) mimics the monarch's coloration and pattern. In North America thousands of monarchs gather in autumn, migrate southward (sometimes traveling more than 2,900 kilometres [about 1,800 miles]), overwinter (occasionally reproducing), and begin to return north in the spring. During the return journey the monarchs stop along the way, deposit eggs, and die. After hatching and maturing, the new generation continues the northward trip. The monarch caterpillar grows to a length of 45 mm (1 4/5 inches) and pupates as a pale-green, golden-spotted chrysalis.