1. S.Camazine MTFrazier Insects: Dressed for Success

2. Insects are the smorgasbord of the animal world!

3. Who Eats Insects?

4. birds fish arthropods (insect and non-insect) amphibians mammals reptiles humans even plants!

5. Do insects take this lying down?

6. Insects have an arsenal of defense mechanisms

7. Morphological / Physical Chemical Behavioral

8. Insects have an arsenal of defense mechanisms Morphological / Physical –camouflage (crypsis) –mimicry –mechanical Chemical Behavioral

9. Insects have an arsenal of defense mechanisms Morphological / Physical –camouflage (crypsis) –mimicry –mechanical Chemical –toxins –venoms –pheromones Behavioral

10. Insects have an arsenal of defense mechanisms Morphological / Physical –camouflage (crypsis) –mimicry –mechanical Chemical –toxins –venoms –pheromones Behavioral –death feigning –“house” construction

11. Camouflage Blend into their background by looking like their background MTFrazier 1) Morphological:

12. Blend into their background by breaking up their body outline (disruptive coloration) MTFrazier

13. …but it doesn’t work from every angle! MTFrazier

14. Blend into their background by looking like some uneatable part of their background MTFrazier

15. Monarch butterfly = toxic Viceroy butterfly = aposematically "dressed" because it doesn’t have the chemical toxins 1) Morphological: Mimicry Aposematism: warning coloration

16. Looks like a bee, BUT this is actually a fly! Bee-mimic = No venom to back up aposematism

17. Mimicry: Batesian - the aposematic inedible model (monarch) has an edible mimic (viceroy) - the model suffers, aposematic signal is diluted

18. Mimicry: Müllerian - both the model and the mimic are distasteful - all benefit from co-existence because predators associate all aposematic color individuals as toxic

19. 1) Morphological: Mechanical Scott Camazine

20. 2) Chemical: Pheromones Toxins: sequestered or produced Venoms S. Camazine

21. Chemically defended insects are typically very apparent to their predators: warning colors S. Camazine

22. Where do insects get their toxins?

23. 3) Behavioral: MTFrazier

24. 3) Behavioral: DIY ‘House Building’ MTFrazier

25. These defense mechanisms often work in combination: Toxins and venoms + aposematic coloration (or sometimes camouflage) Camouflage + behavior Mechanical + chemical

26. In some cases toxins and venoms can be costly for insects to produce Aposematic coloration = primary defense Venoms and toxins = secondary defense S. Camazine MTFrazier

27. Camouflage = primary defense Chemicals = secondary defense MTFrazier

28. It’s not enough to look like a twig (or thorn, stick, etc.) You have to ‘act’ like one to survive! Camouflage + Behavior MTFrazier

29. This caterpillar is even MORE ‘painful’ than it looks mechanical + chemical S. Camazine

30. How did these defenses come about? Evolution By the process of Natural Selection

31. Governing principles of Natural Selection Populations of species have variability Variation is maintained by sexual reproduction Variations can be passed from one generation to the next Individuals that have variations (traits) that make them better able to survive (adapted) in their environment are more likely to survive and pass on their variation (traits/genes) to the next generation

32. Camouflage in caterpillars First Generation

33. Second Generation

34. ? Third Generation

35. Other factors, in addition to natural selection, influence how species evolve over time: Mutations Genetic isolation

36. Review Insect Defense Mechanisms: Morphological / Physical –camouflage (crypsis) –mimicry –mechanical Chemical –toxins –venoms –pheromones Behavioral –death feigning –“house” construction