Practice: Types of Metamorphosis by Emily Amodei

What is metamorphosis?

amodeiemily — 2024-05-20 16:31:46 UTC

Every living thing has a unique life cycle. Metamorphosis is the life cycle by which insects undergo significant changes in form and structure as they develop from an egg into an adult. The word metamorphosis comes from the Greek words meta, which means change, and morphe, which means form.

Types of Metamorphosis

amodeiemily — 2024-05-20 16:44:17 UTC

There are two primary types of metamorphosis that occur in insects: complete metamorphosis and incomplete metamorphosis. Each type follows specific developmental stages.

Complete Metamorphosis

amodeiemily — 2024-05-20 16:45:42 UTC

In some species, newly hatched organisms look different from the adults. Over time, the body drastically changes as a result of metamorphosis. This is true for insects that use complete metamorphosis.

Insects that use complete metamorphosis pass through four distinct stages: egg, larva, pupa, and adult. Each of these stages serves a specific purpose in the insect’s development.

Egg: The life cycle begins with the egg, where the insect develops.
Larva: Once the egg hatches, the insect enters the larval stage, which is the feeding and growing stage. Larvae look very different from adults and may resemble worms or caterpillars. They are primarily focused on eating and growing quickly.
Pupa: After the larva has grown, it enters the pupa stage. During this time, the insect undergoes a dramatic transformation in its body structure to resemble the adult form. The pupa does not feed and is usually immobile.
Adult: The adult insect emerges from the pupa. In this stage, the insect is fully formed, with the ability to reproduce. The adult stage typically includes wings and fully developed body parts.

More than 80% of insects, including flies, beetles, bees, butterflies, and moths, go through complete metamorphosis. Adult female insects continue the life cycle by reproducing and laying eggs.

Incomplete Metamorphosis

amodeiemily — 2024-05-20 16:47:12 UTC

Insects that undergo incomplete metamorphosis have three stages: egg, nymph, and adult. This type of metamorphosis is called “incomplete” because the insect’s form changes gradually as it matures, rather than undergoing a dramatic transformation.

Egg: The insect begins its life as an egg.
Nymph: After hatching, the insect enters the nymph stage. Nymphs resemble miniature versions of the adult but lack wings and reproductive structures. Nymphs molt (shed their outer layer of skin) several times as they grow.
Adult: The nymph reaches maturity, developing wings and reproductive organs, at which point it becomes an adult.

Insects like grasshoppers, cockroaches, praying mantises, and dragonflies use this type of metamorphosis.

Comparing Types of Metamorphosis

amodeiemily — 2025-05-14 13:57:40 UTC

Differences

Number of stages: Complete metamorphosis has four stages, while incomplete metamorphosis has three.
Body changes: Complete metamorphosis involves a drastic change in form from pupa to adult. In incomplete metamorphosis, the changes are gradual, with nymphs looking similar to adults.

Similarities
Despite their differences, both types of metamorphosis share some key features. Both complete and incomplete metamorphosis involve an egg from which the insect hatches, and both require growth and development through several stages before reaching adulthood. Additionally, the adult stage in both types of metamorphosis is the reproductive stage, where the insect can mate and lay eggs to start the life cycle again.