Who hasn't watched in delight as playful butterflies flutter from flower to flower? Butterflies are more than just a pretty face, however. They play an important role in the ecosystem by pollinating flowers. Although they are among nature's most beautiful insects, butterflies aren't born pretty. Caterpillars that transform into butterflies require a little time.
A butterfly's life cycle
A butterfly's life cycle goes through four stages: egg, larva, chrysalis, and finally adult. While a caterpillar's main goal is to feed, an adult butterfly also needs to reproduce. The life cycle of certain butterflies can be as short as one month, while others can live as long as an entire year.
Stage one: The egg
The adult butterfly attaches a large number of eggs on plant or tree leaves. The eggs are small and can be round, oval or cylindrical in shape and can also be plain, ribbed or have special features. The shape and design of the eggs depend upon the butterfly that produced them. The butterfly eggs, and in particular the Monarch eggs, are translucent, enabling you to see the growth of the small caterpillar.
Stage two: The larva
After three to seven days, the caterpillar emerges from the egg with a big appetite. For the next two to three weeks, all it does is eat. During this growth period, the caterpillar sheds its skeleton a few times. Once the caterpillar is big enough, it will shed its final skeleton and attach itself, upside down, to a branch or stem by spinning its own silk.
Stage three: The chrysalis
The chrysalis is the intermediate stage between the caterpillar and the butterfly. Approximately 24 hours after exerting tremendous effort, the caterpillar sheds its exoskeleton and transforms into a chrysalis. If you come upon a caterpillar in the chrysalis stage, there doesn't appear to be much going on inside the sac. However, on the inside, the caterpillar's anatomy is maturing into an adult butterfly.
Stage four: the butterfly
After one or two weeks, the transformation is complete and the butterfly gets ready to emerge. During this process, the butterfly releases hormones to soften the shell of the chrysalis and pushes its way out. For a time the butterfly will cling to the chrysalis. Unable to fly at this stage, the butterfly must pump fluid from its body to its wings in order to harden them. This process can take several hours.
The lifespan of a butterfly depends on variety. While the average lifespan is about a month, the dangers of the environment such as disease and predators can shorten a butterfly's life span significantly. Small butterflies might live only a week while the larger variety such as Monarchs can live up to nine months.
Different kinds of butterflies
About 20,000 different kinds of butterflies flutter around the world. In Mexico, about 2,000 different species have been identified, with about 575 species moving around the United States, and 275 migrating all the way to Canada. When the weather turns cold, butterflies move to warmer regions.
If you are unable to witness the transformation of caterpillars into butterflies in the wild, you can purchase a kit to study their cycle at home.