Myriapoda and Hexapoda

1. Myriapoda and Hexapoda Chapter 15

2. Characteristics • Enormously successful • 750,000 species • Many undescribed • 75% of all living species

3. Characteristics • Insect dominance • Waxy epicuticle • Flight

4. Sub Phylum Myriapoda • Four Classes • Two Body Tagmata • Head • Trunk • Uniramous appendages • Terrestrial

5. Class Diplopoda • Class Diplopoda • Millipedes • 11 to 100 trunk segments • 2 appendages per trunk segment

6. Class Diplopoda • Most are round in shape • Live all over the world • Low level of wax on epicuticle

7. Class Diplopoda • Eat dead and decaying plant material • Roll into a ball • Prevent desiccation • Defense

8. Class Diplopoda • Repugnatorial glands • Hydrogen Cyanide production • Gain appendages and segments as they molt

9. Class Chilopoda • Class Chilopoda • Centipedes • Nocturnal • One pair of appendages per trunk segment • 15 or more segments

10. Class Chilopoda • Last pair of appendages are used for sensory • Flat body • Eat small arthropods, earthworms, and snails or frogs and rodents

11. Class Chilopoda • Poison claws are modified first appendages • Fast for their size • Large tropical species can kill humans

12. Class Pauropoda • Class Pauropoda • Soft bodied animals • 11 segments • Feed on fungi and decaying plant matter

13. Class Symphyla • Class Symphyla • Three tagmata • No eyes • 12 segments with single pairs of legs

14. Subphylum Hexapoda • Two Classes • Three Tagmata • Five head appendages • Three pairs of legs on each thorax

15. Class Insecta • Class Insecta • Most successful land animals • One pair of antenae • Wings • Three pairs of legs

16. Class Insecta • External Structure • Three tagmata • Head • Single pair of antennae • Compound eyes • Sometimes ocelli

17. Class Insecta • Thorax • Three segments - prothorax, mesothorax, and metathorax • Wings with veins

18. Class Insecta • Abdomen • 10 to 11 segments • Lateral folds to allow for expansion • Spiracles

19. Class Insecta • Flight • Insects were the first animals to fly • Wings are thought to have come from protective coverings

20. Class Insecta • Direct or synchronous flight • Grasshopper, butterflies, and dragonflies • Muscles at the base of wings and on the exoskeleton

21. Class Insecta • Indirect or asynchronous flight • Flies and wasps • Muscles change the shape of the exoskeleton • Fibillar flight muscles

22. Class Insecta • Other Locomotion • Walk, swim, run, or jump • Cockroach reaches speeds of 5km/hr. • Fleas can jump 100 times their size

23. Class Insecta • Nutrition • Three segment gut

24. Class Insecta • Biting Mouthparts • Labrum – upper lip • Sensory • Mandible – Chewing (teeth) • Maxillae – cutting surface, sensory • Labrium – Sensory lower lip • Hypopharynx – tongue-like structure • Grasshoppers

25. Class Insecta • Sucking Mouthparts • Mosquitoes

26. Class Insecta • Sponging Mouthparts • Labellum – modified labium • Saliva is secreted • Mouth sponges up liquid • Flies

27. Class Insecta • Gas Exchange • Trachea open to spiracles • Store bicarbonate • Aquatic insects diffuse straight to water

28. Class Insecta • Circulation • Similar to other arthropods • Amoeboid cells • Ectotherms or heterotherms • Shivering Thermogenesis

29. Class Insecta • Nervous • Similar to annelids • Some can learn • Setae and mechanoreceptors • Johnston’s Organs • Tympanal Organs

30. Class Insecta • Excretion • Malphigian tubules • Uric acid

31. Class Insecta • Chemical regulation • Controls many functions • Pheromones

32. Class Insecta • Reproduction • Controlled by a number of factors • Food, photoperiod, population density, temperature, and humidity • Indirect fertilization • Silverfish and springtails

33. Class Insecta • Metamorphosis • Ametabolous metamorphosis • Hemimetabolous metamorphosis • Holometabolous metamorphosis

34. Class Insecta • Insect Behavior • Most innate • Social qualities • Castes

35. Class Insecta • Only 0.5% harmful to humans • 65% pollinate plants • Control qualities • Some parasitic • Lice, fleas