Butterfly Life Cycle
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School children and butterfly exhibits annually celebrate the life cycle of the butterfly.
Technically the life cycle is called a complete metamorphosis because the butterfly, like other insects such as beetles and wasps, goes through a four stage process: egg, larva, pupa and adult.
EggA butterfly's life begins as an egg, usually laid on the leaf of the caterpillar's host plant. It measures about the size of a pinhead, and generally looks like a small clear to black splotch of gel.
Up close the butterfly egg looks very different, depending on the butterfly species. The clip art image on the left shows a magnified monarch butterfly egg that is oval and has a ribbed pattern.
Again, depending on the species, the caterpillar will hatch from the egg in a matter of days or a couple of weeks.
The second stage of metamorphosis is called the larval stage, and, more often than not, the caterpillar that hatches from the egg looks completely different than its butterfly form.
Caterpillar bodies consist of segments, usually thirteen, which can be hairy or smooth. Different species also can have a different numbers of legs. One trait caterpillars share is a big appetite.
During their lifespan, which can last from a couple of weeks to a couple of months, caterpillars live to eat. Most consume the leaves of their host plant. A few caterpillar species are insectivores that feed on aphids.
All caterpillars go through separate stages of development, called instars, which amounts to growing and shedding skin during their growth process. Caterpillars often change colors from one instar stage to another.
At some point in time, a caterpillar's internal clock sets off an alarm that tells the caterpillar to start spinning a new home. It makes a silk button on a branch and then attaches itself to the button. It then sheds its skin for the last time, with the new skin being the hard shell called a chrysalis.
The chrysalis provides protection while the caterpillar body transforms into a butterfly body. The process takes anywhere from a couple of weeks to a couple of months, depending on the species. Many species that develop in the fall spend the winter in their chrysalis and emerge in the spring.
At the transformation from a caterpillar to a butterfly nears its end, the chrysalis becomes clear, making it easy to see the soon to be butterfly behind its walls.
The chrysalis begins to crack and the butterfly crawls out. It holds on to chrysalis for a short time (as shown in the top picture) in order that its wings gain form and strength. Then it flies away to begin life as a butterfly, nectaring on flowers and looking for a mate to keep the cycle going.
© 2009 Patricia A. Michaels