1. Introduction to Insects

2. The Study of Insects Known as entomology
Entomologists have described and classified more than 900,000 insect species.
Entomologists discover from 7,000 to 10,000 new species of insects each year.

3. Insect Classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Orders (know these): Coleoptera, Diptera, Hemiptera, Homoptera, Hymenoptera, Lepidoptera, Orthoptera, Odonata

4. Insect Anatomy A hard exoskeleton protects a soft interior.
Divided into head, thorax, abdomen
Most have wings of some type
No Lungs: breathes through spiracles and trachea
insect anatomy web page

5. Mouth Parts Chewing (beetles) Sucking (adult butterflies)
Piercing (true bugs)
Lapping (fly)

6. Insect Growth
The exoskeleton limits the potential size of insects, but provides valuable protection.
To grow and become an adult, young insects shed or molt their exoskeleton.

7. Molting A new, flexible exoskeleton forms beneath the old exoskeleton.
By taking in extra air, the insect expands itself and splits the old skin.
The new, soft exoskeleton starts to harden in minutes.
Once an insect becomes an adult it stops growing.

8. Life Cycles: Metamorphosis
Complete Metamorphosis
For butterflies, the caterpillar is very different from the adult.
Incomplete Metamorphosis
In grasshoppers, the young resemble the adults. The younger stages are called nymphs.
No Metamorphosis
The young are identical to adults, except for gonads.

9. Complete Metamorphosis
egg
adult
larva
pupa

10. Incomplete Metamorphosis
egg
adult
nymph
bigger
nymph