This document provides an introduction to insects. It notes that insects make up the most dominant and diverse group of creatures on Earth, found everywhere from deserts to forests. Insects have evolved many adaptations that have led to their success, including wings that allow for flight, a hard exoskeleton, a decentralized nervous system, and specialized defense and reproduction abilities. The document discusses insect diversity in size, lifespan, diet, and metamorphosis. It outlines insects' importance to ecosystems and humans, from pollination and food to disease transmission. Forensically, the study of insect biology can aid criminal investigations. Overall, the document highlights insects' antiquity, abundance, and fascinating traits that have enabled their enduring presence across

1. An Introduction to
Insect World
(Amazing facts about insects)
RASHMI, M.A
Research Scholar

2. What are insects?
For most of us…..
any small creature crawling /creeping is an insect….
Spider
Centipede
Scorpion
Earthworm
Mites
All these are not insects!!
Millipede

3. Then what are insects??

4. Insects
Most dominant of all creatures on
earth
Great Diversity
Highly abundant
in all ecosystems

5. What is the population size of insects on earth?
?
?

6. Where do you find them?
Most arid desert
to Evergreen
forests
Sea level to
6000m above
sea level
Artic to Antarctica
Hot sulphur spring (55 0)
to
cold polar habits(-2 0 )
….found Everywhere

7. What are the Reasons for
Insect Dominance?

8. Antiquity
200,000 years ago
Modern humans 8-4 million years Bp
Great ape’s
150 -175 million years
Flowering plants
420 million years BP
Collembolans & thysanurans
Oldest hexapodan fossils
575 million years BP
Cambrian explosion
600 million years BP
Protoarthropods
3.2 billion years oldest
unicellular fossils
Earth
6 billion years ago

9. Great range in their body sizes
Insects demonstrate a great range in their body sizes
However, due to their enormous variation in form it is difficult to
make comparisons
Minute parasitic -Mymar species-0.2mm
Longest insect -555mm Pharnacia serratipes
Female stick insect from west Malaysia

10. The long horned beetle, Titanus giganteus
Measuring 15 to 20cm in length
Heaviest weighing beetle, Goliathus goliathus
weighing up to 100grams
The largest Indian beetle, Chalcosoma atlas measuring
Up to 7.5cm
Dynastes hercules
measuring15 to 18cm &
weigh up to 88grams.

11. Queen Alexandra Birdwing
(Ornithoptera alexandrae)
is the largest butterfly in the world,
wing span up to 30cm.
Western pigmy blue from USA
is the smallest butterfly
measures about 1.5cm across the wings

12. Atlas Moth (Attacus atlas)
Found only in Southeast Asia,
the Atlas Moth is the largest of the moth species with the largest
wing surface area—close to sixty five square inches
& a wingspan of up to a foot long.

13. Presence of Functional Wings
Birds, Bats- 1 pair of wings (modified fore limbs)
Insects- true wings evolved independent of any limbs
Wings of Insects have developed over a period of 300 million yrs against
pterosaurs 225 m years
Birds 125 m years
Bats 50 m years

14. Flight provides: Means of escape – Weather
Food
Enemies
Migration in Monarch Butterfly

15. Can Man Race with Insects??
Human
6.2miles (10Km)
per Hour
6
Mosquito
20miles (32Km)per Hour
2
4
5
3
Sphinx moth
33miles (53Km)
per Hour
Honeybee
13miles
(22Km)per Hour
1
Horsefly
91miles (146Km)
per Hour
Dragonfly
61miles (98Km)
per Hour

16. Metamorphosis
Life cycle of Insects
Insects undergo metamorphosis for their growth and
development
Metamorphosis in insects is the biological process of
development.
There are two forms of metamorphosis:
Incomplete metamorphosis and
Complete metamorphosis

17. Nymph
Egg
Adult
Incomplete Metamorphosis

18. Here u can see how a Dragon fly molting its exoskeleton
Nymph to adult formation
Nymph
Adult

19. Complete Metamorphosis
Egg
Larvae
Adult
Pupae

20. Phenological adjustments- facilitating the timing of occurrence of their different stages

21. What is the life span of insects??
1.Termite Queen - 50
years
5. Bees 4/5 Weeks
2. Queen
Ant 25
years
3. Cicadas 17 years
6.Drone Ants 2 Weeks
4. Dragon flies 4 Months
7.Mayflies 24 HOURS!

22. Diversity of food habits
Insects exhibit a great diversity of food habits
Fungivory
Necrophagy
Nectarivores & pollen feeders
Phytophagous
Coprophagy
Carnivory
Powder post beetle
they eat virtually everything that is
organic by origin
Detritivory

23. Exoskeleton
Enormous Reproductive Ability
Decentralized nervous system

24. Specialized offence and defense mechanisms

25. Camouflage

26. Flower mantid
Camo Moth
Dead leaf butterfly
Lichen moth
Dying leaf katydid

27. How insects see?
Insects have mosaic vision

28. Compound eyes, contains from 6 to 28,000 or
more light-sensitive structures, called
Ommatidia, grouped under a lens or cornea
that is composed of an equal number of
hexagonal prism-shaped facets.
Compound eye with no. of Ommatidia
Components of Ommatidia

29. Ultraviolet
Red
Visible spectral range of human and bee

30. Light production for communication
Glow worm emitting light
Lampyridae is a family of insects in the beetle order Coleoptera. They are
winged beetles, and commonly called fireflies or lightning bugs for their
conspicuous crepuscular use of bioluminescence to attract mates or prey

31. Synchronous flashing of lights by
Firefly larvae in forest

32. Magnesium ions & ATP
lanterns (part of their abdomens)

33. Communication by chemicals
This system is used in finding food,
mates, marking territories, defense,
marking food etc.
Female producing Signal
through chemicals
This system is very specialized & sophisticated
Male having special organ for
sensing the signal

34. What is the importance of insects to man?
Pests
Pollination
Live stock
Crops
Transmit diseases
Ecosystem functions
Pollination
Energy transfer
Nutrient cycling
Scavenging
Earth moving
Scavenging
Fig wasp
A dung beetle hard at work

35. Predators & Parasitoids
Adult
Parasitoids
Tricogramma sp
Green lace wing
Adult parasitizing on
Helicoverpa egg
Larvae feeding on aphid
Stalked eggs
Predatory coccinellids
Ground Beetle Attacking
Caterpillar
Cryptolaemus montrozeri

36. Weed killers
Zygogramma bicolorata
Opuntia- Cactoblastis cactorum
Parthenium weed

37. Medicinal uses
The venom of honey bees is used to ameliorate inflammatory and
autoimmune conditions such as multiple sclerosis, arthritis, rheumatism,
Maggots have been used to treat abscesses, burns, cellulitis,
gangrene, ulcers.
Model organism- Genetic studies & Evolutionary theories
Gene expression
Genetic recombination
Genetic inheritance

38. Food Products
Insects are an extremely rich source of high quality proteins, fats, essential
vitamins, and minerals.
Honey, Human food, Pet food, Livestock feed
Secretions and Dyes
Fine fabrics-Silk
Royal jelly
Extends the life span
Treating some bone, joint disorders &
rheumatoid arthrit .

39. Beeswax
polishing woods, making candles,
packaging, processing, preserving
foods, cigarette filters & waterproofing
material
Shellac
the basic ingredient of a vast list of products,
including stiffening agents in the toes and soles of
shoes and felt hats, shoe polishes, artificial fruits,
lithographic ink, glazes in confections, phonographic
records, playing card finishes, and hair dyes.
Iron gall ink
Oaks produce Aleppo galls in
response to a chemical
substance secreted by
larvae of the cynipid wasp,
Cynips gallae-tinctoriae
Inks
Lac insect

40. Dactylopius coccus
Dactylopius coccus, used in the preparation of red dye
The insects’ bodies contain the pigment called carminic
acid
Carmine is considered safe enough for use in eye
cosmetics
A significant proportion of the insoluble carmine pigment
produced is used in the cosmetics industry for hair- and
skin-care products, lipsticks, face powders, rouges, and
blushes
A bright red dye and the stain carmine used in
microbiology
The pharmaceutical industry uses cochineal dye to color
pills and ointments

41. Medical Entomology
Insect are vectors of human diseases
1.Mosquitoes – Malaria, yellow fever & dengue, filariasis,
encephalitis. Mosquitoes are responsible causing the most human deaths
worldwide than any other animal-almost two million annually
Dengue transmitting Mosquito
2. House flies – Dysentery, typhoid, cholera
3. Tsetse flies – African sleeping sickness
4. Horse flies & deer flies – Anthrax
Vector of Malaria
SN: Anopheles quadrimaculatus
Tsetse fly
House flies
horse flies

42. Forensic entomology
Is the application and study of insect and other arthropod biology to
criminal matters
In murder investigations it deals with which insects eggs when and
where, and in what order they appear in dead bodies
Clothes moth
Insects exhibit a degree of endemism & well-defined phenology
Flies, beetles, mites, moths, wasps, ants &bees.
Flesh fly
Carrion beetle
Hister beetle
Rove beetles
blowfly

43. Insects have served as excellent models for artisans,
architects, engineers, craftsmen
& designers
Beetle inspired water harvester
Stenocara beetles live in the Namib Desert (southwest coast of Africa), one of the
driest places on Earth (0.4 inches of rain annually) and this beetle has developed a
unique technique to survive by obtaining water from early morning fogs.

44. The only monument in the world built to honor an
Agricultural Pest
Boll Weevil
Boll Weevil Monument

45. Top ten reasons to study entomology
10. The Nobel Prize in Physiology and Medicine has been
awarded to biologists studying insects. How will you know which insect to work on
for your Nobel Prize unless you study insects?
9. Over half of the 2 million species described in the world are insects,
thus there is a certain generality that pertains to all studies of insects.
If you’re interested in biodiversity or ecology you need to study insects.
8. Many physiological processes, such as nutrient specific hunger, are similar in
insects and other animals, but are easier to study in insects.
7. Many serious diseases across the world have insect vectors.
You’ll need to learn insect biology if you want to cure a disease.

46. 6. More species of insect have their genome sequenced than any
other type of multicellular organism. To study the blueprint for life,
insects are a great place to start.
5. Insects have been around for 370 million years and have evolved
solutions to many problems that still confound engineers.
The new field of biomimetic design builds on the
functional morphology of insects.
4. Insects live on all continents. Small flies even live year
round on Antarctica. You can travel the world and work
with insects where ever you go.
3. Students studying insects get in to top graduate schools
or get great jobs
2. Insects affect billions of $$ in agriculture for good as
pollinators and bad as herbivores. Study such insects and you can help society.

47. 1. And the top reason to study
insects is:
Insects are just too cool !

48. Acknowledgements
Dept of Entomology, UAS, GKVK.