How Long Should Butterflies Stay in Their Cocoons?

Butterflies are a miracle of nature. Beginning life as an egg and then hatching into a larvae, usually called a caterpillar, it crawls around eating plants and increasing in size. Then, one day, it finds a place to hang and spins a cocoon that hardens into a chrysalis. The chrysalis, or pupa, breaks open, and a completely different-looking creature appears. Scientists call it metamorphosis--the wonderful transformation into a beautiful butterfly.


The caterpillar grows and then creates a protective case known as a chrysalis, which is the pupa stage. Caterpillars make their cocoons using silk that they secrete from glands located inside their bodies. The threads of silk stick together and become hardened when touched by air. The chrysalis has a protective hard coating that may have camouflage colouring. Then the caterpillar remains inactive inside while an amazing transformation takes place. The adult structures of the butterfly are formed, and the larval structures are broken down.

Time Frame

The chrysalis is a surprisingly versatile case. It can open in as little as 2 weeks with a fully formed monarch butterfly or last through an entire winter in areas with snow, such as the cabbage white that emerges in spring. Other cocoons offer protection for the larva during the entire dry season, and pupation waits until the spring rains occur, as in the Tegeticula yuccasella. The giant Queen Alexandra's birdwing stays in the cocoon for about 40 days. The large blue pupates in ant nests for an entire winter until new adults emerge fully formed the following summer.


There are wide varieties of cocoon designs spun by insects that go through metamorphosis. They may be soft, tough, hard, semitransparent, opaque, shiny, glittery or dull. The structure can be mesh that is loosely structured or solid and closely woven, consisting of a single layer or multiple layers. The black swallowtail creates a chrysalis of brown or green to hide it in the foliage for up to 2 weeks, although it can hibernate the entire winter inside as well. The pupa of the Queen Alexandra's birdwing can be well over 3 inches in length with light brown colouring interposed with patches of yellow in irregular patterns to offer camouflage for 40 days of protection until the adult emerges. The monarch butterfly creates a chrysalis that looks like a beautiful green jewel with gold specks of decoration.


Butterflies live all over the world with the exception of Antarctica and come in different colours, shapes and sizes. A butterfly's home can control how long the butterfly remains in the pupa stage. In the tropics, butterflies continue to reproduce and therefore go through pupation any time of the year. The most remarkable delay in emergence from the pupa may be the Mojave Desert pima orange-tip. This butterfly is able to remain in a chrysalis until it senses enough moisture to emerge so it will have plants for food. If the desert moisture is not high enough between January 1 and February 15, the butterfly's host plants will not be able to germinate, so the butterfly will not have food. Therefore, it will not emerge during the season but wait for the next year. In a test lab, the pupae survived in the chrysalis for a full 9 years until emerging when the moisture was adequate.


The chrysalis may start becoming transparent about a day before the butterfly emerges and the wing pattern becomes visible through the skin. Watch for butterflies to emerge from their chrysalises early in the morning. At first, their wings look very small and wrinkled. As the butterflies hang and dry in the sun, their wings fill out and begin to look normal. The morning cloak butterflies of Eurasia separate from each other to pupate for about 3 weeks. When they emerge, they look for woodlands and gardens to store up fat for hibernation. These adult butterflies hibernate. You may want to consider planting a butterfly garden in your yard to attract native butterfly species and offer them protection. Many butterflies are on endangered lists due to overcollecting and loss of native habitat.

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About the Author

Julia Fuller began her professional writing career eight years ago covering special-needs adoption. She holds a bachelor's degree in accounting from Marywood College, is co-owner of GJF Rental Properties as well as a livestock and grain crop farm. She worked for the United States Postal Service and a national income tax service.