Monarch Butterfly
The Monarch of Migration
The Monarch butterfly (Danaus plexippus) is a milkweed butterfly (subfamily Danainae), in the family Nymphalidae. It is perhaps the best known of all North American butterflies. Since the 19th century, it has been found in New Zealand, and in Australia since 1871 where it is called the Wanderer. In Europe it is resident in the Canary Islands, the Azores, and Madeira, and is found as an occasional migrant in Western Europe. Its wings feature an easily recognizable orange and black pattern, with a wingspan of 8.9–10.2 centimetres (3½–4 in).[ (The Viceroy butterfly has a similar size, color, and pattern, but can be distinguished by an extra black stripe across the hind wing.) Female Monarchs have darker veins on their wings, and the males have a spot called the "androconium" in the center of each hind wing from which pheromones are released. Males are also slightly larger.
The Monarch is famous for its southward migration and northward return in summer in the Americas which spans the life of three to four generations of the butterfly.
The Monarch butterfly is known by scientists as Danaus plexippus, which in Greek literally means "sleepy transformation." The name, which evokes the species' ability to hibernate and metamorphize, is actually inspired by the Greek myth of Danaus, in which the daughters of Danaus, king of Libya, flee Libya for Greece in order to avoid marrying their cousins. The long, migratory journey of the Monarch butterflies is reminiscent of the daughters' flight.
Adult Monarchs possess two pair of brilliant orange-reddish wings, featuring black veins and white spots along the edges. Their wingspan is about four inches, and they weigh less than half an ounce. Males, who possess distinguishing black dot (stigmata) along the veins of their wings, are slightly bigger than the females.
Each adult butterfly lives only about four to five weeks. But one of the many wonders of the Monarchs is the annual creation of a unique "Methuselah generation." As autumn approaches in their sites of migratory origin, a very special generation of butterflies is born. Unlike their parents, grandparents, great-grandparents, and great-great-grandparents — all of whom had ephemeral lives measured only in weeks — these migratory butterflies survive seven or eight months. In human terms, given our average life span of 75 years, this would be like having children who lived to be 525 years old!
This generation performs the incredible feat of flying from Canada and the United States to the center of Mexico — after which they begin the northward journey again. Once they reach the United States, a kind of relay race begins: their short-lived offspring, with only four or five weeks to live, continue making the trek northward over several generations.
