Cocoon

A protective casing spun by an insect larva before pupation. It shelters the pupa while the insect undergoes metamorphosis.

Silk: A natural protein fiber produced by certain insects and other animals. Many larvae spin cocoons from silk proteins secreted through specialized glands.
Larva: An immature animal that differs in form from its adult stage. The larva constructs the cocoon before entering pupation.
Sericulture: The raising of silkworms to produce raw silk. Sericulture harvests the silk cocoons made by domesticated silkworm larvae.
Silkworm: The larva of a silk moth, especially the domesticated Bombyx mori. Silkworms produce the best-known commercial silk cocoons.
Spinneret: An organ that extrudes silk or other fiber-forming material in certain animals. A larva draws cocoon fibers from silk glands through its spinnerets.
Holometabolism: Insect development through egg, larva, pupa, and adult stages. Cocoons occur in some insects with a distinct pupal stage.
Bombyx mori: The domesticated silkworm moth, raised chiefly for silk production. Its larvae spin the commercially valuable cocoons used in sericulture.
Luna moth: A large North American moth in the family Saturniidae. Its caterpillar spins a silk cocoon, often among leaf litter.
Silk gland: A specialized gland that produces silk proteins in animals such as silkworms and spiders. The gland supplies the protein solution that hardens into cocoon fibers.
Insect cuticle: The external covering of an insect, made chiefly of chitin and proteins. The cocoon is an external shelter, distinct from the insect’s own cuticle.

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