METAMORPHOSIS OF INSECT
Metamorphosis refers to the process through which insects develop, grow and change form.
Metamorphosis actually infers "change." The term is of Latin and Greek origins: meta means change and morphe means form.Metamorphosis describes the series of changes through which an insect
passes in its growth from the egg stage (some insects, such as aphids, may produce eggs and/or give birth to live young) through the immature stages (ex., nymph, larva or pupa) to the adult stage.
There are two forms of insect metamorphosis (Simple Metamorphosis and Complete Metamorphosis):
Simple Metamorphosis (Egg > nymph > adult)
Insects with simple metamorphosis have three life stages: egg, nymph and adult. Adults and nymphs of these insects usually feed on the same foods. These insects may have wings, which if present, develop externally. Young are known as nymphs and there is no resting stage (pupa).
Some naming conventions provide sub-categories for simple metamorphosis as follows:
1) insects with no metamorphosis or no apparent metamorphosis (such as Springtails, Order: Collembola);
2) insects with incomplete metamorphosis (such as Dragonflies, Order: Odonata); and
3) insects with gradual metamorphosis (such as True Bugs, Order: Hemiptera).
Complete Metamorphosis (Egg > Larva (more precisely: larval instars) > pupa > adult )
Insects with complete metamorphosis have four (4) life stages: egg, larva, pupa and adult. Larvae are very different in form from the adult. The active immature stages are known generally as larvae.
These insects also have a resting stage known as a pupa. The pupal stage is a transition stage, when the larva transforms into the adult. Wings, if present, develop internally within a pupa. The pupa
molts to the adult form.
Insects with complete metamorphosis include lacewings (Order Neuroptera), beetles (Order Coleoptera), butterflies and moths (Order Lepidoptera), true flies (Order Diptera) and wasps and bees (Order Hymenoptera). In some insect orders, larvae are referred to by other names, such as maggots (flies), caterpillars (butterflies and moths) or grubs (beetles). Larvae of insects with complete metamorphosis usually have chewing mouthparts; many are pests of various crops.