introduction to insect world

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

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you can find answers to what are insects, evolution, why are they dominant creatures on earth, population size, where they are found, life cycle, how insects see, etc.,

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Page 1: Introduction to insect world

An Introduction to

Insect World (Amazing facts about insects)

RASHMI, M.A Research Scholar

Page 2: Introduction to insect world

What are insects? For most of us…..

any small creature crawling /creeping is an insect….

All these are not insects!!

Scorpion Centipede

Earthworm Mites Millipede

Spider

Page 3: Introduction to insect world

Then what are insects??

Page 4: Introduction to insect world

Great Diversity

Insects Most dominant of all creatures on

earth

Highly abundant in all ecosystems

Page 5: Introduction to insect world

What is the population size of insects on earth?

? ?

Page 6: Introduction to insect world

Where do you find them?

Artic to Antarctica

….found Everywhere

Sea level to 6000m above

sea level

Most arid desert to Evergreen

forests

Hot sulphur spring (55 0) to

cold polar habits(-2 0 )

Page 7: Introduction to insect world

What are the Reasons for Insect Dominance?

Page 8: Introduction to insect world

Antiquity

Earth 6 billion years ago

3.2 billion years oldest unicellular fossils

600 million years BP Protoarthropods

575 million years BP Cambrian explosion

Collembolans & thysanurans Oldest hexapodan fossils

420 million years BP 150 -175 million years Flowering plants

8-4 million years Bp Great ape’s

200,000 years ago Modern humans

Page 9: Introduction to insect world

Longest insect -555mm Pharnacia serratipes

Female stick insect from west Malaysia

Minute parasitic -Mymar species-0.2mm

Insects demonstrate a great range in their body sizes

However, due to their enormous variation in form it is difficult to

make comparisons

Great range in their body sizes

Page 10: Introduction to insect world

The long horned beetle, Titanus giganteus

Measuring 15 to 20cm in length

Dynastes hercules

measuring15 to 18cm &

weigh up to 88grams.

The largest Indian beetle, Chalcosoma atlas measuring

Up to 7.5cm

Heaviest weighing beetle, Goliathus goliathus

weighing up to 100grams

Page 11: Introduction to insect world

Western pigmy blue from USA

is the smallest butterfly

measures about 1.5cm across the wings

Queen Alexandra Birdwing

(Ornithoptera alexandrae)

is the largest butterfly in the world,

wing span up to 30cm.

Page 12: Introduction to insect world

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.

Page 13: Introduction to insect world

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

Page 14: Introduction to insect world

Flight provides: Means of escape – Weather Food Enemies

Migration in Monarch Butterfly

Page 15: Introduction to insect world

Can Man Race with Insects??

Mosquito 20miles (32Km)per Hour

Honeybee

13miles

(22Km)per Hour

Sphinx moth 33miles (53Km) per Hour

Dragonfly 61miles (98Km) per Hour

Horsefly 91miles (146Km) per Hour

Human 6.2miles (10Km) per Hour

1 2

3

4

5

6

Page 16: Introduction to insect world

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

Metamorphosis

Page 17: Introduction to insect world

Incomplete Metamorphosis

Nymph

Egg Adult

Page 18: Introduction to insect world

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

Nymph

Adult

Page 19: Introduction to insect world

Egg Larvae

Pupae

Adult

Complete Metamorphosis

Page 20: Introduction to insect world

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

Page 21: Introduction to insect world

7.Mayflies 24 HOURS! 6.Drone Ants 2 Weeks 5. Bees 4/5 Weeks

4. Dragon flies 4 Months 3. Cicadas 17 years

2. Queen

Ant 25

years

1.Termite Queen - 50

years

What is the life span of insects??

Page 22: Introduction to insect world

Diversity of food habits

Insects exhibit a great diversity of food habits

they eat virtually everything that is organic by origin

Fungivory Necrophagy Nectarivores & pollen feeders Phytophagous

Carnivory

Coprophagy

Detritivory Powder post beetle

Page 23: Introduction to insect world

Decentralized nervous system

Exoskeleton

Enormous Reproductive Ability

Page 24: Introduction to insect world

Specialized offence and defense mechanisms

Page 25: Introduction to insect world

Camouflage

Page 26: Introduction to insect world

Lichen moth

Dying leaf katydid

Dead leaf butterfly

Camo Moth Flower mantid

Page 27: Introduction to insect world

Insects have mosaic vision

How insects see?

Page 28: Introduction to insect world

Compound eye with no. of Ommatidia

Components of Ommatidia

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.

Page 29: Introduction to insect world

Ult

ravi

ole

t

Red

Visible spectral range of human and bee

Page 30: Introduction to insect world

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

Light production for communication

Page 31: Introduction to insect world

Synchronous flashing of lights by Firefly larvae in forest

Page 32: Introduction to insect world

lanterns (part of their abdomens)

Magnesium ions & ATP

Page 33: Introduction to insect world

Communication by chemicals

Male having special organ for

sensing the signal

Female producing Signal

through chemicals

This system is very specialized & sophisticated

This system is used in finding food,

mates, marking territories, defense,

marking food etc.

Page 34: Introduction to insect world

What is the importance of insects to man?

Ecosystem functions

Pollination Energy transfer Nutrient cycling Scavenging Earth moving

Pests

Live stock Crops Transmit diseases

A dung beetle hard at work

Scavenging

Pollination

Fig wasp

Page 35: Introduction to insect world

Predators & Parasitoids

Ground Beetle Attacking

Caterpillar

Adult parasitizing on

Helicoverpa egg

Parasitoids

Tricogramma sp

Cryptolaemus montrozeri

Predatory coccinellids

Green lace wing

Larvae feeding on aphid

Stalked eggs

Adult

Page 36: Introduction to insect world

Weed killers

Zygogramma bicolorata

Parthenium weed Opuntia- Cactoblastis cactorum

Page 37: Introduction to insect world

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

Page 38: Introduction to insect world

Food Products

Insects are an extremely rich source of high quality proteins, fats, essential vitamins, and minerals.

Honey, Human food, Pet food, Livestock feed

Royal jelly Fine fabrics-Silk

Extends the life span Treating some bone, joint disorders & rheumatoid arthrit .

Secretions and Dyes

Page 39: Introduction to insect world

Beeswax

polishing woods, making candles, packaging, processing, preserving foods, cigarette filters & waterproofing material

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.

Shellac Lac insect

Inks

Iron gall ink Oaks produce Aleppo galls in response to a chemical substance secreted by larvae of the cynipid wasp, Cynips gallae-tinctoriae

Page 40: Introduction to insect world

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

Dactylopius coccus

Page 41: Introduction to insect world

Medical Entomology

Insect are vectors of human diseases

Vector of Malaria

SN: Anopheles quadrimaculatus

Dengue transmitting Mosquito

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

2. House flies – Dysentery, typhoid, cholera

3. Tsetse flies – African sleeping sickness

4. Horse flies & deer flies – Anthrax

House flies horse flies Tsetse fly

Page 42: Introduction to insect world

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

Insects exhibit a degree of endemism & well-defined phenology

Flies, beetles, mites, moths, wasps, ants &bees.

Flesh fly

blowfly

Rove beetles

Hister beetle

Carrion beetle

Clothes moth

Page 43: Introduction to insect world

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.

Beetle inspired water harvester

Insects have served as excellent models for artisans, architects, engineers, craftsmen

& designers

Page 44: Introduction to insect world

The only monument in the world built to honor an

Agricultural Pest

Boll Weevil Monument

Boll Weevil

Page 45: Introduction to insect world

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.

Page 46: Introduction to insect world

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.

Page 47: Introduction to insect world

1. And the top reason to study insects is:

Insects are just too cool !

Page 48: Introduction to insect world

Acknowledgements Dept of Entomology, UAS, GKVK.