2. WHAT IS METAMORPHOSIS?
The word "metamorphosis" comes from a Greek word that
means 'to transform'.
Insect metamorphosis is a biological process of
transformation or abrupt changes in the insects' body
structures, shapes and functions at different stages of life.
Metamorphosis can also be defined as the changes in form
as they grow from an egg to an adult.
These changes may be accompanied by addition and/or
subtraction of body parts.
Some undergo only minor changes while most undergo
extreme changes in structure and function.
3. TYPES OF METAMORPHOSIS
Ametabolous (Little or No Metamorphosis)
Hemimetabolous (Incomplete Metamorphosis)
Paurometabolous (Gradual Metamorphosis)
Holometabolous (Complete Metamorphosis)
4. AMETABOLOUS
METAMORPHOSIS
Most primitive insects that are wingless, such as springtails,
silverfish and firebrats show this type of metamorphosis.
These insects undergo little or no true metamorphosis over the
course of their life cycles.
When they emerge from their egg, immature ametabolous
insects look like tiny versions of their adult counterparts.
They continue moulting and growing until they reach sexual
maturity.
5. HEMIMETABOLOUS
METAMORPHOSIS
EGG
NYMPH
ADULT
A simple type of metamorphosis, also called incomplete
metamorphosis.
This metamorphosis is marked by three life stages: egg,
nymph and adult.
These insects pass through several nymphal life stages before
the nymph molts to the winged adults.
As they approach adulthood, wings appear on their back.
Nymphs resemble the adults in most ways, particularly in
appearance, and exhibit similar behaviors.
Example; Dragonflies, Mayflies, Stoneflies, etc.
6. PAUROMETABOLOUS METAMORPHOSIS
Also called gradual metamorphosis.
This metamorphosis is also marked by three life stages:
egg, nymph and adult.
The newly hatched young ones resemble the adult in
general body form but lacks wings.
The young nymphs undergo several nymphal stages
through successive moulting to transform into adult.
Example; Cockroaches, Grasshoppers, etc.
7. HOLOMETABOLOUS METAMORPHOSIS
Also called complete metamorphosis.
This metamorphosis is marked by four life stages: egg,
larva, pupa and adult.
Each stage of their life cycle is marked by a distinctly
different appearance.
The larva of holometabolous insects bear no
resemblance to their adult counterparts.
The larval forms of most insects is more worm like than
insect like with tiny or no legs, and often use a worm-like
wriggling movement to move.
Larva molt to form a “resting” stage called a pupa in
which the insects are incapable of coordinate
locomotion.
Example; Butterflies, Beetles, Fleas, etc.
