1. Topic
Compound Eyes Of
Entomology

2. Contents Receptors in Insects Photoreception in Insects Compound Eyes
Ommatidia
Components of Ommatidia
Photochemistry of Insect vision
Forms of Compound Eyes
Significance of Compound Eyes
Color vision in Some Orders Of Insects
Summary
References

3. Receptors in Insects Mechanoreceptors Auditory receptors
Stretch receptors
Chemoreceptors
Olfactory receptors
Gustatory receptors
Thermo receptors
Photo receptors

4. Vision is the perception of light. Roles of vision in insects
Photoreception in Insects
Vision is the perception of light. Roles of vision in insects
Entomology

5. Photoreception in Insects
Photoreceptors: 1. Ocelli. 2. Stemmata 3. Compound eyes

6. Dorsal ocelli
In larvae of hemimetabolous insects and in nearly all adults.
Poor perception of form.
Active in orientation to a light source.
Ref.02

7. Stemmata In larvae of holometabolous insects
Do not produce clear images
Most caterpillars can discriminate some shapes and they can orientate themselves with respect to boundaries.

8. Compound Eyes: Most adult insects have a single pair of compound eyes.
Reduced or absent in parasitic forms, many soil insects, and in some species that live in very dark places.

9. Compound Eyes and ocelli

10. Hexagonal Components of Compound Eye.
Facet:
Hexagonal Components of Compound Eye.
Entomology

11. Ommatidia Basic unit of compound eyes Vary in size and number.
Honey bee has 4900 Ommatidia in Queen, 6300 in workers and in donors.
Pomera punctatissima have only one ommatidium in each eye.
The sizes of Ommatidia vary from about
5 to 40 microns in diameter .
Ref.02

12. Components of Ommatidia
Optical parts:
1. Corneal lens
2. Crystalline cone
Sensory parts:
1. Retinula cells
2. Rhabdom
A nerve axon projects
from each retinula cell.
Optic nerve
(YADAV. M)
YADAV. M, "Physiology of Insects," Discovery Publishing House New Delhi , pp
Ref.01

13. Compound Eyes and Brain

14. Photochemistry of Insect vision
Photons are caught on the rhabdome by retinal.
Retinal is connected to opsin, forming rhodopsin.
On absorption of photon, retinal changes its form from bent to straight.
When retinal changes its form, it separates from the rhodopsin and the opsin triggers a nerve cell.
The nerve cells conduct the signal to the brain.
Ref.02

15. Forms of Compound Eyes Apposition eyes 2. Superposition eyes. Ref.01
YADAV. M, "Physiology of Insects," Discovery Publishing House New Delhi , pp
Ref.01

17. Significance of Compound Eyes
Flicker effect
The compound eye is excellent at detecting motion.
As an object moves, ommatidia are turned on and off.
Ref.03

18. Significance of Compound Eyes
2. Distance Perception
Most insects must be able to judge distance.
As in prey catching insects, in Grass hopper’s jumping, and when they are landing.
Simultaneous stimulation of ommatidia.
YADAV. M, "Physiology of Insects," Discovery Publishing House New Delhi , pp
Ref.01

19. Colors

20. Significance of Compound Eyes
3. Color vision
Some insects are able to distinguish colors
Most flower visiting insects exhibit preferences for blue and yellow.
Important in feeding and in court ship behavior

21. 3. Color vision Bichromatic Insects. Trichromatic Insects.
One pigment absorbs green and yellow light (550 nm); the other absorbs blue and ultraviolet light (<480 nm). 
Trichromatic Insects.
Absorption maxima at 360 nm (UV), 440 nm (blue-violet), and 588 nm (yellow)

22. Human Vision Vs. Insect Sight
Colors visible to insects is higher in frequency (lower in wave length)
Violet light is the highest frequency of color humans can detect, but many insects can see a higher frequency of light invisible to us, ultraviolet light.
REF 04

23. Ultraviolet vision
Entomology

24. Color vision in Some Orders Of Insects

25. 1. Vision in Order Hymenoptera
Eastern honey bee (Apis cerana).
Family: Apidae
The bees are red-blind.
“orange, yellow, and green are the same color” – yellow.
Sensitive to UV light.
They see blue colors best.
Sense of polarization of visible light in the sky.
Ref.05

26. 2. Vision in Order Odonata
Dragonfly(C. aenea) or Downy emerald
Family: Corduliidae
Compound eyes with wide-angle vision
Their eyes do not move.
30,000 eye ommatidia
Orange to ultraviolet (UV) light.
Able to estimate distance based on the
distance between their eyes.
Ref.06

27. 3. Vision in Order Diptera
House flies (Musca domestica)
Family: Muscidae
The vision of the housefly is blurred
Compound apposition eyes
Can sense rapid motion approaching 200
cycles per second.
Ref.06

28. Vision in Mosquito Mosquito (Culiseta longiareolata) Family: Culicidae
Mosquitoes are attracted to black and to dark colors. (Howlett 1910)
Prefer the corners of a three-dimensional target. (Brown & Bennett)
Ref.07

29. 4. Vision in Order Coleoptera
Beetle (Tetraopes tetrophthalmus)
Family: Cerambycidae
Have infrared detection systems
for night vision, fire detection, and other functions as to sense forest fires.
Beetles have refraction superposition eyes
Ref.06

30. 5. Vision in Order Blattaria
American cockroach (Periplaneta americana),
Family: Blattidae
2000 individual lenses
Has receptors for UV light and green light.
Ref.08 30

31. 6. Vision in Order Homoptera Aphids Super family: Aphidoidea Contains green, blue, and ultraviolet photoreceptors
Ref.09

32. 7. Vision in Order Lepidoptera
Butterfly(Papilio rutulus)
Family: Papilionidae
Can See simultaneously in every direction.
Trichromatic vision
It can distinguish night from the day
Can perceive colors in a high frequency
(from 310 nm to 700)
Ref.10

33. Vision in Order Lepidoptera
Gipsy Moth (Lymantria dispar).
Family: Lymantriidae
Can see in the back of their heads.
Neural summation
Have three types: blue, green, and ultraviolet.
Ultraviolet light reflection.
Ref.12

34. Summary
Compound Eyes of Insects

35. References
YADAV. M, "Physiology of Insects," Discovery Publishing House New Delhi , pp

36. References 8. 9.
10.
11.
12.

37. Good listeners make Good Speakers
Thank You Very Much
Good listeners make Good Speakers

38. Dedicated To
Dr. Sumera Afsheen .