What is a Cocoon?
A cocoon is a protective envelope that insect larvae use to develop into their pupal stage. The cocoon also serves to protect the insect from predators and mortality from hostile weather. The correct humidity and temperature within the cocoon enable the larva to transform into its adult stage.
How Are Cocoons Formed?
Cocoons are formed to help larvae safely metamorphize into adults. The larvae live in their cocoons for 5-21 days. Some insects form their cocoon by shedding their larval skin, much like a snake sheds its skin. Underneath the shed skin is a hard shell that functions as the structure in which the insect safely lives until it hatches from the cocoon. Other kinds of cocoons are formed when the insect produces a large quantity of silk to create a “sleeping bag” shelter to house and protect it. Other cocoons, like those of fleas’, are made by the adult flea’s production of sticky silk that collects debris, which hides the larvae in its habitat.
Difference Between Pupa, Chrysalis, and Cocoon
The words cocoon and chrysalis are often used interchangeably when speaking about butterflies and moths. However, they are two completely different things. Cocoons are specific to moths, while chrysalises are formed by butterflies. Insects that mature through a process known as complete metamorphosis enter a stage called the pupa stage before entering the adult stage. Generally, moths make cocoons that are wrapped in a silk covering and are soft and porous. Butterflies make a chrysalis, which is generally hard, sturdy, and smooth with no silk covering.
Different Types of Cocoons
Mud cocoons. These are typically formed by mud dauber wasps and other insects that emerge as adults in mud or cocoons in moist soil.
Cocoons made of silk. These are often called a “sleeping bag” type of cocoon.
Cocoons that are formed by shedding the larval skin to reveal a chrysalis. Butterfly chrysalises are typically produced in this manner.
Ant cocoons. Adult ants protect the ant cocoons from parasitic insects. The cocoon ants excrete a sugary liquid that adult ants use as a source of nutrition.
Common Pests That Build Cocoons
Numerous insects build cocoons, many of which are common plant and household insects. Most cocoon builders are insects that are not pests but rather are valuable contributors to helping control populations of other pests. Butterflies and moths are the most well-known cocoon-encasing insects. Other commonly encountered cocoon makers include bees, wasps, fleas, flies, ants, and stored product beetles.