How to Tell the Difference Between a Pupa and a Cocoon

Among insects, butterflies and moths are unique, transforming through four distinct life stages. These four stages include embryo, larva, pupa and imago. When referring to the third stage in the life cycle of butterflies, the term chrysalis is used instead of pupa. A cocoon is a hard protective outer covering woven by the moth to cover the pupa. It attaches its cocoon to a leaf, branch or any surface using an intricate web if silk-like threads spun in a pattern that resembles Velcro. When moths transform into pupae, they are immobile, and need the protective outer shell of the cocoon to keep them safe from predators. Without the cocoon, moth pupae would be very vulnerable to predation.

Things You'll Need

  • Magnifying glass
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Instructions

    • 1

      Locate a moth cocoon or butterfly chrysalis. Find these outdoors in parks, woodlands, meadows, or suburban yards. Teachers may want to purchase a butterfly house and kit to raise butterflies inside the classroom. Find moth cocoons close to the ground, usually attached to shrubs, leaves, fences and similar objects. Some moths even place their cocoons directly onto the ground. Butterflies typically affix their chrysalis to more open places, such as shrub leaves.

    • 2

      Using the magnifying glass, examine the cocoon. The pupa sits inside the cocoon, encased in the hard shell. The pupa attaches the cocoon from silks woven from a place on its abdomen. You may not be able to see the pupa. Do not try to open the cocoon or chrysalis to see the pupa, as this may damage or kill the insect.

    • 3

      Determine if you have a moth or butterfly cocoon or chrysalis. Moth cocoons are brown, gray or other dark colors. Some moths incorporate dirt, feces, and small bits of twigs or leaves into the cocoon to camouflage themselves from predators. Butterfly chrysalids shine with a golden metallic color.

    • 4

      Watch for the moth or butterfly to emerge. Check daily. It may take days or weeks, depending upon the species. Do not try to help the insect emerge. Let nature take its course. The butterfly or moth will emerge and need a day or so to sit, stretch and dry its wings. Interrupting this process may cause lasting harm to the insect, such as malformed wings. As with many things in nature, watch, observe and enjoy, but don't touch!

    • 5

      Enjoy the beauty of butterflies and moths in the garden throughout the spring and summer by planting a butterfly garden. You'll not only feed the emerging pupae, but provide food, shelter, and breeding spots for subsequent generations.