What makes their wings colorful?

Butterfly wings are covered with scales. Each scale is a single color, most of which are produced by pigments. The iridescence that's sometimes seen is produced from a reflective microstructure on the surface of the scales.

Aside from their beauty and remarkable diversity, some butterflies are champion long distance flyers. The supreme example of long distance displacement among butterflies is the annual migration of the monarch in North America. The northern race of this beautiful insect migrates the length of the sub-continent - a distance of some 3,200 km - between its breeding areas in Canada and the northern United States and its over-wintering sites in the southern United States, California and Mexico.

Adult monarchs start to move south from the northern breeding sites in July and by September vast numbers can be seen on the move. They apparently move by daylight only, feeding on the way, and on the whole do not fly at a great height but maintain a southerly direction. Mark and recapture experiments have proved beyond doubt that this butterfly regularly covers distances in excess of 1,900km in only a few days, and at average speeds of up to 130km per day. The longest recorded flight by one insect is just under 3,000km in a period of 130 days. The mark and recapture experiments emphasize the fact that individuals can cover great distances, as do sightings of monarchs several hundred kilometers out to sea and the occasional landings in Britain of these American butterflies which have presumably strayed off course during their southerly flight.

PLAIN TIGER

This species is common throughout the old world tropics. It is also known as the lesser wanderer, due to somewhat migratory habits. Caterpillars feed on milkweed plants, using the toxins in these plants to make them distasteful. The bad taste is retained in the adult phase, and this species displays bright orange and black colors to serve as a warning to predators of the strong, toxic flavor. Several non-toxic species occurring in the same regions have similar color patterns to mimic the plain tiger, giving them protection from predators by appearing to be toxic as well.