Tentorium and neck sclerites

1. ASSIGNMENT ON
TENTORIUM AND NECK SCLERITES
Presented by:
B.SANDEEP
ID NO :-21412EAZ005
M.SC AG Entomology
&Agril.Zoology
Submitted to:
Dr.R S MEENA(Professor)
Dr.Ram keval
Dept of Entomology and
Agri Zoology

2. TENTORIUM
It is an endoskeleton structure.
It is composed of three pairs of arms.
They are:
1. Anterior tentorial arms
2. Posterior tentorial arms
3. Dorsal tentorial arms.

3. • The anterior tentorial arms develop from the anterior tentorial
pits in the subgenal or epistomal suture.
• 2.The posterior tentorial arms arise from the posterior tentorial
pits in the lower ends of the post-occipital suture.
• 3.The dorsal tentorial arms take origin in the form of secondary
out-growths of the anterior arms.
• All these tentorial arms unite in the middle forming an expanded
central skeletal platform. It may simply constitute a structure
resembling the X.

4. Insect head - tentorium

5. • The anterior tentorial pits:
• The anterior tentorial arms of the tentorium arise from some part of subgena or
epistomal suture.
• The posterior tentorial pits:
• The posterior tentorial arms of the tentorium arise from ventral ends of post
occipital suture and lie in the lower extremities of post occipital suture.
• Carpotentorium :- Represents inward extension , meeting and fusion of Anterior
and Posterior arms .It is well developed in Orthoptera .

6. Thorax is the body region situated between head and the abdomen.
The insect thorax is divided into three parts:
(a) Prothorax (pro=first)
(b) Mesothorax (meso=middle)
(c) Metathorax (meta=last)
➤ The insect thorax is a box-like structure and is composed of a number of
sclerites which play an important role in insect locomotion.
► Each segment consists of hardened plates, or sclerites.
1. Dorsal sclerites- notum
2. Ventral sclerites- sternum
3. Lateral sclerites- pleuron
Each of the three thoracic segments contains one pair of legs arise from pleura.
Wings articulated between notal and pleural regions.
THORAX

7. Insect body regions

8. TERGUM
• The tergum of the prothoracic segments-pronotum.
• Prothoracic tergum is an undivided skeletal plate. Tergum is simple in
wingless/immature winged insects and modified in winged insects.
• In winged insects the tergum divided into 2 parts
• a) Alinotum: anterior, wing-bearing portion,internally bears anterior phragma
(antecosta)
b)Postnotum: posterior portion, wingless; -bears posterior phragma –modified for
wing support.
Notum of wing bearing segments is divided by transverse sutures.They are the
prescutum, scutum and scutellum. Scutellum is prominent in Bugs

9. THORACIC STERNA
• Vental body plate of each thoracic segments are called as prosternum,
mesosternum and metasternum.
• Thoracic sterna is made up of a segmental plate called Eusternum and
a intersternite called Spinasternum.
• Eusternum is made up of three sclerites
• Presternum
• Basisternum
• Stemellum

10. THORACIC PLUERA
• Lateral body wall of thoracic segment between notum and sternum.
• Selentes of pleuron is called as pleurites and they fuse to form Pleural plate.
• Pleural plate is divided into anterior episternum and posterior epimeron by Pleural
suture. Pterothoracic pleuran provides space for articulation of wing and leg.
• Thoracic appendages are three pairs of legs and two pairs of wings.
• Two pairs of spiracies are also present in the mesopleuron and metapleuron
Functions of thorax: Mainly concerned with locomotion.