Monarch butterflies are beautiful and their life cycle is fascinating and their habitat should be protected.
One of the most beautiful creatures on earth, the Monarch butterfly, is in danger. The favorite food of Monarch larvae, milkweed, is taking a hit from habitat destruction, herbicide spraying, and over mowing of roadsides. Monarchs are food for two species of birds. Although most birds refuse to eat Monarchs (they taste terrible due to a poisonous chemical defense called cardenolides) several million butterflies are consumed annually by black headed grosbeaks and black backed orioles at the butterflies' winter home in Mexico. More ominous is the devastating effect genetically engineered corn pollen is having on Monarch populations.
Fortunately, the plight of these gloriously colored insects has caught the attention of preservationists. The life cycle, habitat, diet and migration habits of the Monarch are under intense scrutiny by researchers and lay people alike. Thanks to a growing buzz on the Web, everyone can learn more about the Monarch's life cycle and how we can help by planting butterfly gardens and by avoiding the use of pesticides.
The life cycle of the Monarch begins in the U.S. and Canada. Up to four generations of Monarchs are produced in a season. The last group begins its journey to its overwintering grounds near Mexico City or coastal California in the fall, a trip that can extend more than 2500 miles. The four-stage life cycle of a butterfly hatched in spring is short, only a few weeks. A Monarch hatched in the fall could live as long as nine months.
Female butterflies may lay up to 1000 eggs on any of 108 species of milkweed plants. The egg-to-butterfly stage takes about a month. The egg hatches into a caterpillar with yellow, black and white stripes. The caterpillar grow fast; he will sheds his skin several times before changing into pupa covered in in a silk-like substance called a chrysalis. Then a metamorphosis takes place; the fat, striped caterpillar transforms into a beautiful orange and black butterfly.
When the temperature begins to drop, Monarchs begin their long trip south. The Monarchs' movements south are propelled by temperature changes; because the insects are essentially cold blooded; they cannot fly when temperatures drop. Monarchs travel in large clusters, helped along by air currents. Some yet to be understood mechanism guides them by the millions to the same roosting places in central Mexico. Late in the afternoon, Monarchs stop for the evening, clinging to pine, eucalyptus and other trees. A tree full of sleeping Monarchs, wings folded in repose, is an awesome sight.
During their time as butterflies, Monarchs forget all about their former lives as caterpillars when they fed exclusively on the lowly milkweed. As nectar eating insects, their long, curled tongue, guided by a keen sense of smell, seeks the intoxicating elixir offered up by nectar bearing wild and cultivated flowers.
Unfortunately for the Monarch, danger lurks around the edges of the cornfields; toxic pollen from genetically modified corn blows onto milkweed plants and finds its way into the larvae's stomach. There, the crystalline endotoxin produced from bacterium genes, designed to kill the corn borer, eats away at the Monarch's insides. The pathogens released into the insects' bodies kill large numbers of them (50 per cent in one study) and cause the other 50 per cent to grow to half their normal size.
If you love Monarchs and want to attract them to your property, use natural pesticides or better yet, learn to peacefully coexist with a few pests in the interest of creating a more pristine environment for the Monarchs.
Plant a butterfly garden. Remember that they love purple, red, orange and yellow blossoms. Plant zinnias, New England asters, bee balm, purple coneflower, marigold, verbena, cosmos, black-eyed Susan, goldenrod and lavender. Most important, plant milkweed. Seeds and planting instructions are available from Monarch Watch, an excellent Web site hosted by the University of Kansas. Monarch Watch offers packets of five different milkweed varieties, along with planting and growing instructions.
For an excellent color map showing the Monarch's habitat and migration patterns, check out the World Wildlife Federation's Web site.
By doing your part, you can help preserve the habitat and life cycle of the "Daughter of the Sun" as they were called by the ancient Masahuas in central Mexico.
