INSECT THORAX

Insect Thorax

- 3 segmented

Prothorax Mesothorax Metathorax

Pterothorax

Anterior Posterior

pleuron

notum

sternum

pleuron

Cross section of insect thorax

pleuron

notum

sternum

Insect Thorax

scutum scutellum

epimeron

basisternum

trochantin

sternellum

tergum

episternum

pleuron

notum

sternum

Insect Thorax

Internal support in thorax

pleural ridge

pleural apophysis

sternal apophysis

sternopleural muscle

furca

FurcaPleural/sternal apophysis Apodemes

Thoracic Appendages - Legs

coxa

trochanter

femurtibia

tarsus

pretarsus

tarsomeres

coxa

Insect Leg - Articulation

monocondylic

leg

Insect Leg - Articulation

monocondylic trochantin

leg leg

Insect Leg - Articulation

monocondylic

Decreasing mobility

Increasing strength

trochantin dicondylic

leg leg leg

Thoracic Appendages - Legs

Modifications

Digging (Fossorial)

Mole cricket (Orthoptera:Gryllotalpidae)

Thoracic Appendages - Legs

Modifications

Saltatorial (jumping)

Migratory locust (Orthoptera: Locustidae)

Thoracic Appendages - Legs

Modifications

Natorial (swimming)

Predaceous diving beetle (Coleoptera:Dytiscidae)

Thoracic Appendages - Legs

Modifications

Pneustonic (water surface)

Whirlig beetle (Coleoptera: Gyrinidae)

Thoracic Appendages - Legs

Modifications

Apposition (grasping)

Thoracic Appendages - Legs

Modifications

Cursorial (running)

Tiger beetle (Coleoptera: Cicindellidae)

Thoracic Appendages - Legs

Modifications

Suction (mating pads)

Predaceous diving beetle (Coleoptera:Dytiscidae)

Thoracic Appendages - Wings

Development

cuticle

haemocoel

Evagination of body wall

1.

2.

blood(hemolymph)

tracheanerve

cuticle

epidermis vein

The Insect Wingcosta

subcosta

radius

medial

cubitusanal

jugal

C

Sc

R

RS

MA

MP

CuA

CuP

A

J

The Insect Wing

Wing modifications

Dragonfly (Odonata)-archedictyon

Evolutionary Trends

1. Reduce number of cross veins = loss of weight

2. Fuse or lose longitudinal veins

3. Less sclerotization

4. Reduce fluting except on anterior

The Insect Wing

Wing folding

The Insect Wing

Wing folding

Melolontha

Wing Coupling

Paleoptera

Wing Coupling

Frenate (Lepidoptera)

frenulum retinaculum

male

female

Wing Coupling

Hamate (Hymenoptera)

Hamuli (hooks)

Wing Coupling

Jugate (Lepidoptera)

Wing Coupling

Overlap (Lepidoptera)

The Insect Wing

Wing modifications

Elytra (Several Orders) elytra

The Insect Wing

Wing modifications

Hemelytra (True Bugs - Hemiptera)

The Insect Wing

Wing modifications

Halteres

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INSECT FLIGHT