METAMORPHOSIS IN INSECTS
Metamophosis is defined as the series of gradual changes of form and shape of an insect from the fertilised egg (immature stage) to adult (mature stage of adulthood).
Certain organisms when they are hatched from eggs do not directly resemble the adult form.
They therefore undergo series of changes in shape or form until the adult stage is reached. This process is what is called metamorphosis.
Types of Metamorphosis
There are two types of metamorphosis. These are complete and incomplete metamorphosis.
1) Complete metamorphosis
Complete metamorphosis is the series of gradual changes which take place in insect from fertilised eggs to lava, then to pupa and finally to the adult stage. Complete metamorphosis involves four stages which are:
eggs -> larva -> pupa -> adult.
Examples of insects which exhibit complete metamorphosis include housefly, mosquito, butterfly, bees, wasp and beetles.
2) Incomplete Metamorphosis
Incomplete metamorphosis is defined as the series of gradual changes in insects which take place from fertilised eggs to nymph and finally to the adult stage. Incomplete metamorphosis involves only three stages. They are:
eggs -> nymph -> adult.
Examples of insects which exhibit incomplete metamorphosis include grasshopper, cockroach, dragonfly, locust, aphids, termites and praying mantis.
Differences Between Complete and Incomplete Metamorphosis
- Four stages of development are involved.
- There is presence of pupa (resting stage).
- There is no resemblance between pupa and adult.
- There is absence of nymph.
- Examples of complete metamorphosis are housefly and mosquito.
- Three stages of development are involved.
- There is absence of pupa (no resting stage).
- There is a resemblance between nymph and adult.
- Nymph is present.
- Examples of incomplete metamorphosis are cockroach and grasshopper.