Metamorphosis in insects ,Its types (Mubaika seher)

Metamorphosis
its Types

2. DEVELOPMENTAL BIOLOGY
Mubaika sehar
baf1800548
BS Zoology (5
th
)morning

4. METAMORPHOSIS IN INSECTS AND ITS
TYPES
Contents
Metamorphosis
Ametabolous
Gradual metamorphosis
Compeletemetamorphosis
Incompeletemetamorphosis
Metamorphosis in insects
Metamorphosis in Butterfly
Harmonalcontrol in metamorphosis

5. Metamorphosis
Definition
“Metamorphosisis a biological process by
which ananimalphysically develops after birth or hatching,
involving a conspicuous and relatively abrupt change in
theanimal'sbody structure through cell growth and
differentiation.”
Four Stages
Egg
Larva
Pupa
Adult

6. Types Of Metamorphosis
1.Ametabolousmetamorphosis
•Little or no metamorphosis
•eggs immatures
•same shape as the adults.
•get bigger no distinct rearrangements of body structures .
•Immatures juveniles.
•Changes in form during growth are minor
•all immature stages resemble adults.
Examples
i.Springtail
ii.silverfish
iii.firebrats

7. Ametabolous metamorphosis

8. 2. Gradual metamorphosis
Paurometabola
Immatures are called nymphs.
Change in form is gradual,
obvious changes involving
development of external wing pads
differences in color or markings.
Nymphs and adults generally share the same
habitat
Examples
i.Grasshoppers
ii.crickets
iii.true bugs

9. Gradual metamorphosis

10. Complete metamorphosis
•“In complete metamorphosis a larva completely changes its
body plan to become an adult”.
•Holometabolous
•Four stages
i.Egg
ii.Larva
iii.Pupa
iv.Adult
Immatures are called larvae and pupae.
Larvae do not resemble adults.
Wings and other adult features ….an immobile pupal stage
Immatures and adults may or may not share habitats
Immatures are adapted for feeding
adults are adapted for reproduction and dispersal.
Butterflies, moths, beetles, flies, ants, bees and wasps

11. Compelete metamorphosis
Four stages
Egg
Larva
Pupa
Adult

12. Incomplete metamorphosis
In incomplete metamorphosis, only some parts of the
animal’s body change during metamorphosis. Animals that
only partially change their bodies as they mature are called
“hemimetabolous,”
Three stages
i.Egg
ii.Nymph
iii.Adult

13. Incomplete metamorphosis
Immatures are called naiads.
Immatures do not closely resemble adults
naiads have tracheal gills.
transition to adult form is gradual
Nymphs and adults dwell in different habitats.
Examples
Mayflies ,dragonflies ,damselflies and stoneflies

14. Metamorphosis in butterfly
Butterfly Life Cycle
•The Egg
•A butterfly lays her eggs
on a leaf.
•The Larva
•The egg hatches and out
comes a caterpillar , this is
the larva stage.

15. The Pupa
•The Caterpillar stops
eating and becomes a
Pupa or chrysalis

16. The Butterfly Stage
The Butterfly
•Hhh
•From the Chrysalis a butterfly
emerges

17. The Life Cycle of a Butterfly

18. Metamorphosis in
Ladybug

19. Metamorphosis in insects
Insectmolting andmetamorphosisarecontrolledby two
effectorhormones: the steroid 20-hydroxyecdysone and the lipid
juvenilehormone(JH)
in immature insects Corpora allata………….juvnile
hormone
inhibits the genes ,promote development of adult
causing the insect to remain "immature"
The corpora allatashrink during the last larval or
nymphalinstar
stop producing juvenile hormone. and causes the
insect to molt into an adult (hemimetabolous) or a
pupa (holometabolous).
approach of sexual maturity
brain neurosecretory cells
brain hormone "reactivates" the corpora allata
• juvenile hormone.

20. Cont..
In adult females , stimulates production of
yolk for the eggs.
In adult males ,stimulates the accessory
glands to produce proteins needed for
seminal fluid and the case of the
spermatophore.
In the absence of normal juvenile hormone
production, the adult remains sexually
sterile

21. 20-hydroxyecdysone
•20-hydroxyecdysone initiates and
coordinates each molt and regulates
the changes in gene expression that
occur duringmetamorphosis.

22. Harmonal Control in Insects

23. References
https://www.britannica.com/science
/metamorphosis
https://www.slideshare.net/iqra666/
metamorphosis-in-insects
https://www.slideshare.net/ARUN5
218/metamorphosis-and-diapause-
in-insects
https://link.springer.com/chapter/10
.1007%2F978-1-4613-3246-6_4