Lab 3

1
Lab 3

• Insects

2
Three Subphyla in Arthropoda

• Insecta
• Crustacea
• Arachnida

3
Characteristics
4
The Grasshopper (Romalea)

• Insect is divided into three major segments
• - Head
• - Thorax
• - Abdomen

5

• cuticle armor-like body covering (exoskeleton),
  made up of sclerites
• sclerites interconnecting plates which allow
  for flexibility. Held together by sutures.
• sutures in between sclerites, allow relative
  movement.
• tergum dorsal sclerite
• pleuron lateral sclerite
• sternum ventral sclerite\

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The Head

• Frons (middle and upper face)
• Gena (cheeks)
• Vertex (crown)
• Clypeus (lower face)

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• Frons
• Gena
• Clypeus

A
b
B
B
C
Insects have a single pair of antennae which
arise from the frons.
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Most insects have one pair of compound eyes. The
number of ocelli (simple eyes) is more variable.
9
Mouthparts

• Some insects have no functional mouthparts and
  therefore cannot eat
• The Grasshopper is an herbivore so its
  mouthparts are used for chewing as well as
  holding.
• There are Five Major Parts
• Labrum upper lip of insects and crustaceans
  situated above or in front of the mandibles
• Mandibles (pair) appendages immediately
  posterior to the antennae used to seize, hold,
  bite, or chew food.
• Hypopharynx found in certain insects, in
  appendage or lower fold of the pharynx
• Maxillae (pair, with palps) Either of 2
  laterally moving appendages situated behind the
  mandibles.
• Labium (also with palps) a lip-like structure
• palps elongated, often segmented appendage
  found near the mouth. (sensation, locomotion and
  feeding)

10
Labrum

• Upper lip of insects crustaceans situated above
  or in front of the mandibles.

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12
The Thorax

• Three Segments
• Prothorax
• Mesothorax
• Metahorax
• Forewings are Stiffer than Hind wings
• One pair of legs arises from each thoracic
  division.

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Coxa

• Segment which joins the whole leg to the body.

Trochanter
Coxa
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Femur

• Most pronounced segment

Femur
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Tibia
Tibia
Tarsus

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The Abdomen
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