3 - Aerial locomotion

Question 1

Beetles’ wing structure

Answer 1

Forewings are modified as protective dorsal shield (ELYTRA)
Hind wings are the only functional wings - longer than the ELYTRA and folds underneath it

Question 2

Flies wing structure (10)

Answer 2

Posterior pair of wings are reduced to HALTERES (small dots) and assist with performance and stability

Question 3

Flight - structure

Answer 3

• wings are connected to thorax via complex join (wing hinge)
• join contains resilin

Question 4

Resilin

Answer 4

Highly elastic protein that allows for rapid sustained mvmnt

Question 5

Dorsal side of insect

Answer 5

Notum

Question 6

Ventral side of insect

Answer 6

Pleuron

Question 7

How do taxonomists identify insects?

Answer 7

Use the configuration of the veins and specific landmarks to obtain important taxonomic keys

Question 8

Wings structure

Answer 8

Flexible and have multiple veins with circulating hemolymph

Question 9

Hemolymph

Answer 9

a fluid equivalent to blood in most invertebrates, occupying the haemocoel

Question 10

Optimal functioning of cells in wings require?

Answer 10

That nutrients, waste and signaling molecules be transported into and out of the wings via the hemolymph.

Question 11

Flight aerodynamics

Answer 11

Uplift & drag

Question 12

Wing loading

Answer 12

The ratio of body mass (or size) to wing area - provides a measure of the energetic costs of flying in an animal

Question 13

The larger the wing loading …

Answer 13

The higher the costs to fly - insect becomes too heavy for its wings.

Question 14

Low wing loading

Answer 14

Large wings relative to body size - found where long sustained periods of flight required

Question 15

Why are wings smaller in complex vegetation?

Answer 15

To increase maneuverability - large wings are cumbersome in complex habitat structures

Question 16

Cumbersome

Answer 16

large or heavy and therefore difficult to carry or use, slow and inefficient

Question 17

Wing loading equation

Answer 17

Wing Loading = body mass (g) / wing area (cm^2)]

Question 18

Types of flight mechanisms

Answer 18

1. Indirect flight
2. Direct flight

Question 19

Indirect flight mechanism def

Answer 19

Muscles are used to raise and lower the wings. The thorax deforms through this process causing the wings to move up and down

Question 20

Indirect flight characterized by

Answer 20

• Two opposing set of muscles
• Flexible thorax
• Energy-efficient flight system
• Synchronous or Asynchronous flight muscles
  (Most insects)

Question 21

Synchronous muscles def

Answer 21

• A nerve impulse is required for each and every contraction
• This limits the rate at which the muscles can contract, because it takes time for the physiological processes associated with a nervous stimulus to run their course.

Question 22

Asynchronous muscles def

Answer 22

• Do not require a nerve impulse for every contraction.
• Instead, a nerve impulse now and then is all that is needed to keep these muscles contracting with regularity.
• Wings beat faster than neural transmission

Question 23

What insects have asynchronous muscles and why?

Answer 23

bees, flies, beetles
- achieve very high wing beat frequencies

Question 24

Direct flight def

Answer 24

Muscles are directly attached to the wings and serve to raise and lower them as well as to tilt their plane at different angles

Question 25

What muscles does direct flight use? and which insects have these muscles?

Answer 25

SYNCHRONOUS MUSCLES
Primitive insects
- Ephemeroptera (Mayflies)
- Odonata (Dragonflies & damselflies

Question 26

Gliding def

Answer 26

Species of tropical ants - return to their home tree trunk when they fall from branches.
During the fall- a rapid adjustment in abdomen orientation (pointed towards the tree trunk) directs the path of the falling ant through the air in a steep glide ending at the trunk.
This has also been found in tropical arboreal bristletails (‘silverfish’, ‘fishmoth’, Order Thysanura)

Question 27

Ballooning def

Answer 27

• Spiders use their own silk to create silk draglines that catch the wind and allows the spider to move around
• There is need for a balance between the gravity effect (which creates down-lift) and a drag force from wind (which creates up-lift)
• The velocity of the spider can change depending on body posture or body shape.

Question 28

Velocity of spider ballooning can change depending on?

Answer 28

Body posture or shape

Question 29

In ballooning, balance is needed btwn what?

Answer 29

The gravity effect (down-lift) &
Drag force from wind (up-lift)

Question 30

Wing size affects what?

Answer 30

Aerodynamics

Question 31

What does wing loading affect?

Answer 31

• Endurance
• Maneuverability
• Speed