1. Insects and Their Relatives Section 30.3

2. Insect diversity The largest group of animals Four important orders:  Coleoptera – ‘shield-winged’ like beetles  Diptera – ‘two-winged’ like flies  Lepidoptera – ‘scale-winged’ like butterflies  Hymenoptera – ‘membrane-winged’ like wasps

3. Coleoptera

4. Green bottle fly

5. Butterflies

6. Ants

7. Insect Body Plan 1. Head – has mandibles, specialized mouthparts, one pair of antennae and usually 1 pair of compound eyes 2. Thorax – has three pairs of jointed walking legs; some without wings, others with 1 or 2 pairs of wings 3. Abdomen – has 9 – 11 segments

8. Insect body parts

9. Insect Life Cycle Complete metamorphosis: Almost all insect species egg  larva  pupa in chrysalis  adult Incomplete metamorphosis: egg  nymph  (several molts)  adult

12. Insect Life Styles Flight: Insects were the first animals to develop flight Wings develop from sacs of the body wall of the thorax Most insects can fold their wings over the abdomen – some cannot Social insects: Ants, bees, wasps, and termites Division of labor within the colony

13. Many insects can fly

14. Ants are social insects

15. Insect relatives Centipedes –1 pair of legs per segment; carnivores Millipedes – 2 pair of legs per segment; herbivores

16. Centipedes – 1 pair of legs/segment

17. Millipedes – 2 pairs of legs/segment