Entomology for the Masters

1. Entomology for the Masters • A brief history • Insect overview • Order recognition • Identification activity • Insect evidence • Friend and foe Michael Meyer, Ph.D. Dept. Organismal and Environmental Biology Christopher Newport University

2. John Henry Comstock - the first entomology instructor Comstock  Traver  Edmunds  McCafferty  Meyer

3. What’s not an insect [or “bug”]?

5. Class: Arachnida (arachnids) Order: Opiliones (harvestmen) • single body segment • predators; scavengers of animals and plants • repellent secreted as defense

7. Class: Arachnida (arachnids) Order: Acari (mites, ticks, chiggers) • variety of life histories • predators, herbivores, parasites, suspension feeders • terrestrial and aquatic (fresh and salt water) • may be vectors of disease

9. Class: Arachnida (arachnids) Order: Araneae (spiders) • poison = protein-digesting • fangs are distal portion of chelicerae • spinnerets and silk (six main kinds) production

11. Class: Diplopoda [millipedes] - generally cylindrical • 2 pair of legs on body segments • slow; feed on plants or decaying materials

13. Class: Chilopoda [centipedes] - flattened; one pair of legs on body segments • fast: predators, feed on insects/other arthropods • poison jaws paralyze prey

14. Why should “we” study entomology?

15. Why should we study entomology? • Insects are the dominant group of animals. - the Earth’s most varied organism - 80% of all known animals, 57% of all life - >1 million described species [54K vertebrates]

16. 2. Many insects are valuable to us. • produce goods (i.e., honey, silk), services (i.e., pollination, pest control), and food (i.e., fruits, vegetables) • research animals (i.e., Drosophila, bomb-sniffing wasps)

17. 3. Some insects are harmful. • destroy crops, animals, and possessions • transmit human disease • just plain annoying

18. 4. Insects are fascinating/interesting. • beautiful, fascinating organisms • used throughout human culture/history

19. Why are insects so successful?

20. Factors in the success of insects. • Highly adaptable exoskeleton. • legs suited for locomotion on land and in water • tracheae system for respiration • wax covering to reduce the loss of moisture

21. 2. Colonization of the terrestrial environment before chordates. • Early Devonian (410 MYA) = first fossil record • Early Jurassic (200 MYA) = therians (early mammals)

22. 3. Small body size. - occupy an enormous variety of small places

23. 4. High birthrate and short generation time. • little time to grow to maturity (due to small size) • increased potential for genetic change in populations

24. 5. Highly efficient flight. • escape unfavorable habitats and colonize new ones • escape enemies, find food, mates, places to oviposite

25. 6. Life history with metamorphosis. • reduced competition between larvae and adults • larvae utilized food inaccessible to adults

26. Generalized Body Regions

28. Head - mouthparts

29. Wings

30. Wings - generalized [membranous] [dragonfly]

31. Wing modification

32. Wing modification - elytra [beetle]

33. Wing modification

34. Wing modification - hemelytra [true bug]

35. Wing modification A Blan

36. Wing modification - tegmina [roaches and “songsters”] A Blan

37. Wing modification

38. Wing modification - halteres [true flies]

39. Abdomen

40. Abdomen Aphids: cornicles

41. Abdomen

42. Abdomen Earwig: modified cerci

43. How well do you know the insect Orders?

45. Ephemeroptera [for a day wings] (Mayflies) • larvae are aquatic • subimago life stage • adults w/ vestigial mouthparts • adults w/ two or three long “tails”

47. Odonata [tooth] (Dragonflies and Damselflies) • larvae are aquatic, w/ prehensile labium • wings held perpendicular or parallel to body • predators; catch basket • live 3/4 weeks [damsel], 6/10 weeks [dragon]

49. Orthoptera [straight wings] (Grasshopper, Crickets, and Katydids) • generally with modified hind legs • thickened forewings called tegmina • many are musicians • most are plant feeders [i.e., pests]