1. Chapter 2
Section 3

2. Insect Body 3 body sections 6 legs 1 pair of antennae
Head, thorax, and abdomen
6 legs
Attached to the thorax
1 pair of antennae
Usually 1 or 2 pairs of wings

3. Insect Body Sense organs are located on the head
Eyes and antennae
Abdomen contains the internal organs
2 large compound eyes which contain lenses
Good for seeing movement
Have simple eyes too
Distinguish between light and dark

4. Insect Body Obtain oxygen through a system of tubes
Tubes lead to openings in the insect’s exoskeleton
Air enters the body through the tubes and travels to the cells

5. Egg to Adult Tiny, hard-shelled, fertilized eggs
Go through metamorphosis to become an adult
2 different types of metamorphosis

6. Metamorphosis 2 types of metamorphosis Complete metamorphosis
Gradual metamorphosis

7. Metamorphosis Complete metamorphosis 4 dramatically different stages
Egg
Larva
Pupa
Adult

8. Metamorphosis Complete Metamorphosis
Larva – immature form of an animal that looks different than the adult
Specialized for eating and growing
Pupa
Insect is enclosed in a protective covering and gradually changes from a larva to an adult
After it has completed its development an adult emerges

9. Complete metamorphosis

10. Metamorphosis Gradual metamorphosis
Has no distinctly different larval stage
Egg hatches into a stage called a nymph
Nymph – often resembles the adult insect
A nymph may molt several times before becoming an adult

11. Gradual Metamorphosis

12. Feeding Eat plants and parts of plants (leaves and nectar)
Eat products made from plants such as paper
Feed on animals too
Fleas and mosquitoes feed on blood of living animals
Dung beetles feed on animal droppings

13. Feeding Burying beetles feed on decaying bodies of dead animals
Mouthparts are adapted for a specific way of getting food

14. Defense Hard exoskeleton Run or fly away Smell or taste bad
Painful stings

15. Defense Most common defense is camouflage Resemble other animals
Blend in to their environment
Resemble other animals
Example the spots on wings of some moths resemble large eyes
When predators see these eyes they avoid them

16. Insects and Humans
For every person alive scientists estimate that there are at least 200 million living insects
Insects impact our lives
Damage crops
Carry microorganisms that cause diseases
The vast majority are harmless or beneficial to humans

17. Insects and Humans Insects are harmless or beneficial Bees make honey
Silkworm larvae spin the fibers to make silk
Some insects prey on harmful insects
Some enable food crops
We need insects to have food to eat

18. Controlling Pests We try to get rid of harmful pests using pesticides
This can also kill harmless / helpful pests
Overtime insect populations become resistant to pesticides

19. Controlling Pests
A search for another way to deal with harmful insects
Biological controls
Introduce natural predators or diseases
Ex: Ladybugs added to fields to kill aphids
Soil can be treated with bacteria that are harmless to humans but cause diseases in the larvae of pest insects like the Japanese beetle
Biological controls only kill specific pests and are therefore less damaging to the environment