The Butterfly Life Cycle Explained

by AMNH on

On Exhibit posts

The metamorphosis from caterpillar to butterfly is one of the most iconic transformations in nature.

So what exactly happens during this complicated process?

Stage 1: Egg

All butterflies start as tiny eggs—each about the size of a pin—that female butterflies deposit on leaves in small clusters. Eggs typically gestate for about a week or two, at which point they hatch into butterfly larva.

Stage 2: Larva

Almost all insect species go through larval stages. Fly larvae, for instance, are commonly known as maggots. Butterfly larvae—more commonly known as caterpillars—are more charismatic than most of their cohorts.

Caterpillars are notoriously voracious, consuming grass, leaves, and other plant material as they grow up to 1,000 times their original birth weight. While some species binge and blow up in just a few weeks, others take longer to develop. The wood-eating Carpenter Worm is actually a caterpillar that can take as long as three years to grow out of its larval state.

No matter how long it takes, each caterpillar is eating to prepare for the next stage in its life cycle, when it will put those calories to use to power a startling transformation.

Close-up view of an owl butterfly larva resting on a leaf.
The caterpillar, or larval stage, of an owl butterfly species. 
Courtesy of orestART/Flickr 

Stage 3: Pupa

The next stage of a butterfly's life cycle takes place inside a chrysalis, the last expression of the caterpillar's exoskeleton. While it may not look like much to the naked eye, there are incredible processes occurring in this motionless casement. The caterpillar will break down entirely on a cellular level, and then reorganize itself into a new form. The result is an adult butterfly that emerges from exoskeleton after a period of several weeks. In the video below, Associate Director of Living Exhibits Hazel Davies offers a detailed explanation of this amazing process. 



Stage 4: Adulthood

Adult butterflies leave behind their chrysalis and take to the air on their new wings. Once they reach this stage of life, butterflies spend most of their time looking for a mate, and they may not have long. On reaching adulthood, many butterfly species live for less than a month.

When butterflies succeed in finding a mate, another batch of fertilized eggs is produced and the cycle begins anew.


Owl butterfly sits on a flowering plant, it's extended wings display a bold, spotted pattern.
A species of owl butterfly like those that can be seen in the Museum’s Butterfly Conservatory.
Courtesy of Maxpixel

To learn more about butterflies—and see species from around the world live in a tropical vivarium—come visit The Butterfly Conservatory.