Integument, Molting and Endocrine Control Flashcards
What are the major constituents of an insect cuticle? (2)
- Chitin
2. Proteins
What is lamellae?
A polymer chain of N-acetylglucosamine that are bound by proteins to form sheets
How is the cuticle made unstretchable?
Lamellae are laid down at different angles every half hour
How much of the chitin in the cuticle is reabsorbed during molting?
about 85%
Where are proteins found in the insects cuticle?
Cross-linked to lamellae
What are the layers of the cuticle from the outermost layer to innermost layer? (4)
(Outermost) - Epicuticle - Exocuticle - Endocuticle - Epidermis (Innermost)
What is the function of the Epicuticle?
provides a waterproof layer for the insect and prevent water loss
What is the function of the Exocuticle?
Forms a protective shell (hardened by sclerotization
What is the function of the Endocuticle?
To be reabsorbed during molting. Not sclerotized
What is the function of the Epidermis?
To produce all the layers of the Integument. Only actual living part of the integument
How is wax formed on the Epicuticle and why?
A gland in the epidermis extends all the way up to the top most layer to create the wax covering in order to prevent water loss and waterproof the insect
What are the three stages of molting? (in order)
- Apolysis
- Ecdysis
- Sclerotization
What is Apolysis?
The separation of the epidermis from the cuticle of the previous stage
What is Ecdysis?
The casting off or escape from the residual cuticle of the previous stage. There is a fully formed insect inside the old cuticle prior to this stage
What is Sclerotization (in regard to molting)?
A chemical process that hardens the outer section of cuticle (exocuticle) after ecdysis by cross-linking cuticular proteins with oxidized phenols.
occurs from the outside in.
What is a pharate?
The fully formed insect inside the old cuticle prior to ecdysis
What is an exuvium?
The cast off cuticle after ecdysis
What is a teneral adult?
An insect that has not finished sclerotizing its integument after molting
What are the 6 stages the cuticle goes through during molting?
- Apolysis
- Production of cuticulin
- Digestion of endocuticle
- Resorption of molting fluid
- Cuticle immediately after Ecdysis
- Mature cuticle
What hormone controls sclerotization?
bursicon