Moulting, also known as ecdysis or shedding, is the periodic shedding of an insect's old cuticle and formation of a new one. It occurs multiple times during the immature stages before reaching adulthood. The key steps involve behavioral changes, loosening of the cuticle, formation of a subcuticular space, secretion of moulting fluid, rupture and removal of the old cuticle, and formation of a new cuticle. Moulting is controlled hormonally by the brain, corpora allata glands, and prothoracic glands. It allows for regeneration of damaged tissues and missing limbs.

1. Centurion University of
technology and
management
FUNDAMENTALS OF ENTOMOLOGY-1
Presenting to:-
Dr.Deepayan Padhy
Presented by :-Jami Saranya
Registration number:220804130048

2. Topic:- Moulting-the
process and specificity
towards insect.

3. Moulting in Insects
Moulting
Also known as Ecdysis or
Shedding
Definition
• The periodic shedding of old cuticle and the subsequent
formation of new one is called moulting or ecdysis.
• Moulting are accuring periodically till maturation of insects.

4. Moulting in Insects
● The mechanism of periodical sheding of old cuticle and formation of
new cuticle is known as moulting or ecdysis.
● The old cuticle which is shed off in the process of moulting is known
as exuviae.
● The interval between two subsequent moulting is known as stadium.
The form assumed by the insect in any stadium is called instar.
● Moulting occurs many times during immatured stages before
attaining the adult-hood.

5. EXCUVIA
●The cuticular discarded parts known as
EXCUVIA
• Excuvia are the remains of an
exoskeleton and related structures that
are left after ecdysozoans have moulted.
The exuviae of an animal can be
important to biologists as they can often
be used to identify the species of the
animal.

6. Stadium
• The form assumed in each stadium is called instar.
• A phase between two periods of Moulting in the development of an
insect larva or other invertebrate animal.
Instar
• The time interval between two consecutive moulting is called
stadium.
• The old exoskeleton is visible behind it. Each stage in the
development of an insect between molts is called an instar or
stadium.

8. APOLYSIS
1.Behavioural changes
2.Changes in epidermis
3.Apolysis
4.Formation of subcuticular space
5.Secretion of moulting gel
6.New epicuticle formation
7.Procuticle formation
8.Activatiom of moulting gel
9.Wax layer formation
10.Cement layer formation
ECDYSIS
11.Rupturing and removal of old cuticle
SCLEROTIZATION AND MELANIZATION
12.Formation of Exocuticle
13.Formation of Endocuticle

9. Steps of moulting in insects
1.Behavioral changes:
Larvae stops feeding & become inactive.
2.Changes in Epidermis:
Cell size increase, Activities enhanced. Proteins & Enzyme contents increase and thus
tention cause loosening the cuticle .
3.Apolysis:
Detachment of cuticle from epidermis is occurred.
4.Formation of subcuticular space:
In this stage the space is formed in subcuticular area.

10. 5.Secretion of Gel:
Secretion of molting gel in to sub cuticular space that is rich in chitinase and protease.
6.New epicuticle layer formation:
Lipo protein layers is laid on epidermis .
7.Pro cuticle layer formation:
Pro cuticle layer is formed below epicuticle.
8.Activation of moulting gel:
The gel is converting into molting fluid and digest and absorb the endo cuticle
9.Wax layer formation:
In this stage the wax layer is formed.
10.Cement layer formation:
Dermal gland produce cement layer.

11. 11.Moulting: involved in 2 steps Moulting
(I)Rupturing of old cuticle: As the water and air is absorbed and thus
pressure is generated by blood to head and thorax and “ecdysial line” rupturing take
place.
(II)Removal of old cuticle: Due to peristaltic movement of the body and
Lubricant action of molting fluid helps in removal.
12.Formation of exo cuticle:
The outer layer of pro cuticle develops as exo cuticle.
13.Formation of endo cuticle:
The below layer of pro cuticle develops as endo cuticle.

12. Moulting in Mayfly

13. Hormonal control of Moulting
● MOULTING is controlled by
neurosecretory cells in which brain
which in turn stimulate Corpora
allata(small glands behind the
brain) which produce juvenile
hormone
● Prothoracic glands which produce
moulting hormones (ecdysteroids).
Ecdysteroids stimulate the
epithelial cells in the cuticle to
begin the moulting process

14. Advantage:
● Ecdysis helps in the regeneration of damaged tissue. Also,
missing limbs regenerate or re-form through the ecdysis
process.
● Ecdysis allows damaged tissue and missing limbs to be
regenerated or substantially re-formed. Complete
regeneration may require a series of moults, the stump
becoming a little larger with each moult until it is a normal,
or near normal, size.