Introduction to insect world


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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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Introduction to insect world

  1. 1. An Introduction to Insect World (Amazing facts about insects) RASHMI, M.A Research Scholar
  2. 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. 3. Then what are insects??
  4. 4. Insects Most dominant of all creatures on earth Great Diversity Highly abundant in all ecosystems
  5. 5. What is the population size of insects on earth? ? ?
  6. 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. 7. What are the Reasons for Insect Dominance?
  8. 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. 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. 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. 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. 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. 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. 14. Flight provides: Means of escape – Weather Food Enemies Migration in Monarch Butterfly
  15. 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. 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. 17. Nymph Egg Adult Incomplete Metamorphosis
  18. 18. Here u can see how a Dragon fly molting its exoskeleton Nymph to adult formation Nymph Adult
  19. 19. Complete Metamorphosis Egg Larvae Adult Pupae
  20. 20. Phenological adjustments- facilitating the timing of occurrence of their different stages
  21. 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. 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. 23. Exoskeleton Enormous Reproductive Ability Decentralized nervous system
  24. 24. Specialized offence and defense mechanisms
  25. 25. Camouflage
  26. 26. Flower mantid Camo Moth Dead leaf butterfly Lichen moth Dying leaf katydid
  27. 27. How insects see? Insects have mosaic vision
  28. 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. 29. Ultraviolet Red Visible spectral range of human and bee
  30. 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. 31. Synchronous flashing of lights by Firefly larvae in forest
  32. 32. Magnesium ions & ATP lanterns (part of their abdomens)
  33. 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. 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. 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. 36. Weed killers Zygogramma bicolorata Opuntia- Cactoblastis cactorum Parthenium weed
  37. 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. 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. 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. 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. 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. 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. 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. 44. The only monument in the world built to honor an Agricultural Pest Boll Weevil Boll Weevil Monument
  45. 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. 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. 47. 1. And the top reason to study insects is: Insects are just too cool !
  48. 48. Acknowledgements Dept of Entomology, UAS, GKVK.