Lecture 3 - Thorax, Abdomen, Wings, Legs Flashcards
The combination of mesothorax and metthorax is known as
pterothorax
Function of the thorax
Locomotion
The first pair of the leg is attached to the
prothorax (foreleg)
The second pair of the leg is attached to the
mesothorax (middle leg)
The third pair of the leg attached is known as the
metathorax (hind legs)
The first pair of wings are attached to the
mesothorax
The second pair of wings are attached to the
metathorax
Pronotum
The prothorax is covered by the pronotum (shield) that protects the wing and neck of the insect
Each region of the thorax is comprised of 3 parts:
Notum (Top)
Pleuron (Side)
Sternum (Bottom)
The mesothorax is divided into
(2)
alinotum and the postnotum
The alinotum bears the face and is divided into
(3)
3 segments: Prescutum, Scutum, Scutellum
Function of the pleural suture
It is used to form a point of articulation w/ the coxal cavity and divides the pleuron into episterum (Anterior) and epimeron (posterior)
Components of the insect legs
(5)
a. Coxa
b. Trochanter
c. Femur
d. Tibia
e. Tarsus
Coxa
Proximal segment that is attached to the body of the insect
Trochanter
Provides wide range of movement in the insect)
Femur
provides power and muscle
Tibia
Use as a kicking device in an insect
Insect leg: Swimming
2
Aquatic Hemiptera and Coleoptera
Insect Leg: Jumping
(3)
Orthoptera, Hemiptera, Fleas
Insect Leg: Grasping Prey
(2)
Praying mantids, giant water bug
Insect Leg: Grasping host (2)
Lice, other ectoparasites
Insect Leg: Digging (2)
Scarab beetles, some crickets
Insect Leg: Sound Production (1)
Grasshoppers
Insect Leg: Cleaning and carrying pollen (1)
Honeybee
Insect Leg: Defence
Some leaf insect
Insect Wings
Adult pterygote insects consists of 2 pairs of wings
Exception of Insect Wings (2)
However there is an exception for insects that consists of ONLY 1 pair of wing (Diptera - house flies)
The pair of wings are attached to the mesothorax used for protection and camouflage and the hind wings are modified to be known as halteres
Characterization of an insect wing: Orthoptera
Orthoptera consists of tegmina (which are leathery and hard)
Characterization of an insect wing: Coleoptera
Coleoptera consists of elytra (which are hard and sclerotized) used to protect the membranous hind wings
Characterization of an insect wing: Hempitera
Hemiptera consists of forewings known as hemelytra (these are partial sclerotized wings and partial membraneous)
Insect Abdomen (2)
The abdomen consists of the dorsal surface known as the tergum and the ventral (lower sclerite) known as the sternum
There are 11 abdominal segments whereas there are only 6-7 segments in the abdomen of the flies and beetles
Component of the Insect Abdomen (1-7) segment
There are usually 1-7 similar segments known as pregenital
Component of the Insect Abdomen (8-9)
Segment 8-9 bear the external genitalia (eg. Ovipositor found in female to lay eggs)
Component of the Insect Abdomen (10)
Is usually present
Compoent of the insect Abdomen (segment 11)
Segment 11 is usually reduced to the epiproct and paraproct (sclerites surrounds the anal pore), consisting of a sensory appendages known as the cerci
Component of the Insect Abdomen (Anus)
Anus is present at the end of the insect that is surrounded by the 2 paraproct and 1 dorsal plate known as the epiproct
Cercus
sensory touch and structures located near the anterior margin of the paraproct
Female Abdomen (2)
The female abdomen consists of the ovipositor
The ovipositor consists of 4 valvifers and 6 valvulae
Male Abdomen
The male abdomen consists of the aedeagus (penis)
Other Abdominal Appendages
(7) + Description
a. Other abdominal appendages include prolegs (pseudopods) in lepidopteran larvae
b. Gills in the aquatic larvae
c. Claspers
d. Styli
e. Cerci (earwigs, cockroaches)
f. Pseudo legs (caterpillars)
g. Cornicles (Aphids) Secreting Pheromones
