Arthropods

1. Arthropods Our hard-shelled friends…..and foes!

2. Characteristics of Arthropods • Segmented • Jointed appendages • Hard external skeleton • 3 parts-head, thorax, abdomen (arachnids exception) • Exoskeleton-hard, external skeleton made of chitin • Molting- shed old exoskeleton and secrete a larger one, very vulnerable after molting

3. Body parts • Ganglia-clusters of nerve cells along a nerve cord • Compound eyes-may facets each with their own lenses, some have single lenses and some have both • Spiracles-holes in the exoskeleton that allow gas exchange (book lungs in arachnids) • Trachea-chitin lined tubes in spiracles

4. Arthropod Ancestors-Trilobites

5. Diversity of Arthropods • First arthropods evolved in sea about 560 mya • 4,000 species of trilobites • Spider-like arthropods abundant in sea 300 mya, only 4 species left-horseshoe crabs-changed very little • Crustaceans live in mostly aquatic environments, specialization of appendages;claws

6. Types • Crustaceans-lobsters, crayfish, crabs, shrimp, barnacles, copepods, Isopods (pillbugs,sowbugs) • Arachnids-spiders, scorpions, mites and ticks • Insects-beetles, ants, grasshoppers, butterflies, dragonflies,etc • Myriapods- centipedes-venomous, millipedes- toxic chemicals, smell/taste bad

7. Class Arachnida • Scorpions, spider, ticks, mites • 2 body sections-cephalothorax and abdomen • Chelicerae-fanglike mouthparts to paralyze prey with poison • Pedipalps-mouthpart typically used to manipulate prey once it has been paralyzed or for mating • Malpighian tubules-remove wastes from fluids in body cavity

8. Arachnids • Book lungs-specialized respiratory structures and provide large surface for gas exchange, some use trachea • Almost all arachnids live on land and have several adaptations to help them retain water.

9. Types • Spiders-have silk glands made from spinnerets; many hunt for prey or use webs • Scorpions-nighttime hunters in deserts, venomous stinger at the end of the tail, body glows in a black light • Mites/ticks-suck sap or blood, sucking mouthparts, transmit diseases, Lyme disease, Rocky Mountain spotted fever, tick paralysis

11. Spiders

12. Not really spiders but close…

13. Scorpions All scorpions glow in a black light

14. Mites and Ticks

15. Class Crustacea • Decapods-ten legs, pincers and walking legs, most are marine, crayfish are freshwater and a few land crabs exist in tropical areas • 2 body parts-cephalothorax and abdomen • Carapace-portion of the exoskeleton that cover cephalothorax • Mandibles-bite and grind food • Lobsters, crayfish, crabs, shrimp

16. Barnacles and Copepods • Barnacles secrete calcium carbonate to make their shells • Copepods are very small but play a big part in food chains

17. Isopods • Most are small marine crustaceans, but also include large animals and terrestrial pillbugs/sowbugs

18. Decapods

19. Isopods

20. Barnacles and Copepods

21. Class Insecta • 3 main body parts-head, thorax, abdomen • 6 walking legs • Wings • Malpighian tubules for waste • Tracheal system and spiracles for gas exchange • Young often have completely different behavioral and eating patterns in complete metamorphosis • Entomology-study of insects

22. Class Insecta-Complete Metamorphosis • Changes from one completely different form into another adult form. • Has various stages of larva and pupa before becoming an adult • Pupa is an inactive stage in which a cocoon forms and the insect undergoes major physical and chemical changes. • Examples are: butterflies, moths, wasps, bees, beetles

23. Class Insecta-Incomplete Metamorphosis • Insect goes through various stages of molting and growing but remain basically the same. • Young grows bigger and bigger but has same feeding habits and physical appearance • Examples are: praying mantis, crickets and grasshoppers

24. Class Insecta Includes Many Insect Orders • Coleoptera- beetles • Lepidoptera-butterflies and moths • Diptera- flies and mosquitoes • Hymenoptera- ants, bees, wasps • Hemiptera- the true “bugs” stinkbugs, water striders • Orthoptera- crickets and grasshoppers • Odonata- dragonflies and damselflies • Isoptera- Termites • Homoptera- cicadas, aphids

25. Order Coleoptera Larval Beetle Forms

28. Order Lepidoptera Larval Forms

31. Order Diptera

32. Maggots, Diptera Larvae

33. Order Hymenoptera

34. Order Hemiptera The Kissing Bug, transmits the deadly Chagas disease!

35. Order Orthoptera

36. Order Odonata Larval Forms

37. Order Homoptera Molted skin

38. Cicada Songs • Many of these are from the Southeast Asia areas, but there are cicadas that are quite loud around here.

39. Order Isoptera Termite Queen