Insect body wall is called as Integument or Exoskeleton insect integument ppt.pdf

Insect body wall is called as Integument or
Exoskeleton.
It is the external covering of the body which is
ectodermal in origin.
 It is rigid, flexible, lighter, stronger and variously
modified in different body parts to suit different
modes of life.

1. Subject - Fundamentals of Entomology
Topic: Structure and Functions of Insect Cuticle

Presented by,
Dr. Neelesh Raypuriya
Ph.D. Entomology
Department of Entomology
College of Agriculture, Indore- 452001 (M.P.)

2. Insect Integument or Body Wall
 Insect body wall is called as Integument or
Exoskeleton.
It is the external covering of the body which is
ectodermal in origin.
 It is rigid, flexible, lighter, stronger and variously
modified in different body parts to suit different
modes of life.
Serves as a protective covering over the body,
also know integument

3. The insect integument consisting of
Cuticle
The epidermis or hypodermis
 The basement membrane

4. The cuticle
 It is complex non cellular layer.
 It is outermost thick layer of integument
 Secreted by epidermis.
 When newly formed it is flexible and elastic .
 When undergoes sclerotization it becomes
hardened and darkened

5. Contd...
 It is divided in to two regions:
(A) Epicuticle (Upper) :
It is very thin outer most layer
Thickness 0.03 – 4.00 micron
Chitin is absent in epicuticle
It consists of following 4 layers:
•Cement layer, Wax layer, Polyphenol layer and
Cuticulin layer

6. Contd...
 Cement layer:
Secreted by dermal gland Composed of lipoprotein It
protects the body from external damage
 Wax layer:
 Prominent layer
•Thickness - 0.25 micron
•Consisting long chain hydrocarbons fatty acids and
alcohols
•It serves as water proof layer
•Preventing water loss from the body

7. Polyphenol layer :
Consisting phenols which are mainly used in
the formation of proteins
Resistant to acids and organic solvents
Cuticulin layer :
It is amber colure thin layer
Act as growth barrier


Contd...

8. Contd...

(B) Procuticle (Inner) :
Exocuticle - Darkly pigmented, Hard and sclerotized,
Consisting mainly chitin and hard protein called
Sclerotin.
Endocuticle - Light colored, Soft and unsclerotized,
Consisting more chitin, Lack of Sclerotin
2. Epidermis –
•It is single layer of cells lying below the cuticle.
•Secretes greater part of cuticle and moulting fluid

9. Contd...
3. Basement membrane -
Epidermis resting on basement membrane with the
following:
Function-
 Cuticle secretion
• Digestion and absorption of old cuticle
• Wound repairing
• Gives surface look

10. Contd...

•Protection to the organs
•Gives shape to insect
•Provides surface for attachment of muscles
•Conserve moisture and prevent desiccation
•Prevent entry of pathogens and insecticides
•It forms sense organ
•Contains pigment to make insect attractive
Functions of body wall -

11. Thank You