1. Regular Biology Chapter 28 Waggy
The Insects
Regular Biology
Chapter 28
Waggy

2. Chapter Objectives
1. Discuss & list the general characteristics of insects
2. Trace the taxonomy of the Class Insecta
3. Discuss the characteristics of the external structure of the grasshopper
4. Follow the digestive system of the grasshopper

3. Chapter Objectives…
5. Understand the way the circulatory system of the grasshopper works
6. Discuss the nervous system of the grasshopper
7. Compare & contrast complete metamorphosis & incomplete metamorphosis

4. Insect features The study of insects is called entomology
Exoskeleton is made up of chitin
Bodies are in three segments:
1. Head
Mandible (movable jaws)
antennae
2. Thorax
Three pairs of jointed legs
Up to two pairs of wings (if any)
3. Abdomen
Composed of up to 11 segments

5. Insect Features Insects have thrived for more than 400 million years
Insects live everywhere on earth except saltwater

6. Insect Features
Adaptations that have allowed insects to become so successful on Earth are:
1. Flight
2. Small size to evade predators & inhabit tiny habitats
3. Short life spans & tons of eggs allow for Natural selection to work faster in insects
Today, insects account for more than half of all animals species on Earth

7. Taxonomy Domain: Eukarya Kingdom: Animalia Phylum: Arthropoda
Class: Insecta
Order: there are nine:
5. Orthoptera
6. Coleoptera
7. Diptera
8. Hymenoptera
9. Lepidoptera
1. Hemiptera
2. Homoptera
3. Isoptera
4. Odonata

8. 2. Order: Homoptera 1. Order: Hemiptera ‘half wing’
55,000 different species
These are the true bugs
Damage crops, garden plants & transmit disease
2. Order: Homoptera
‘like wing’
22,000 different species
Aphids, mealybugs, cicadas

9. 3. Order: Isoptera 4. Order: Odonata ‘same wing’
2,000 different species
Termites
4. Order: Odonata
‘toothed wing’
5,000 different species
Dragonflies & damselflies

10. 5. Order: Orthoptera 6. Order: Coleoptera ‘straight wing’
30,000 different species
Grasshoppers, crickets, katydids
6. Order: Coleoptera
‘sheathed wing’
400,000 different species
Weevils, ladybugs, all beetles

11. 7. Order: Diptera 8. Order: Hymenoptera ‘two wing’
120,000 different species
Mosquitoes, flies & gnats
8. Order: Hymenoptera
‘membrane wing’
100,000 different species
Bees, wasps, ants

12. 9. Order: Lepidoptera ‘scaled wing’ 140,000 different species
Butterflies & moths

13. The Grasshopper: external structure
The head:
Simple & compound eyes
Unbranched antennae
Mouthparts

14. The Grasshopper: external structure…
The thorax is divided into three parts:
Prothorax
Attaches to the head & has the first pair of walking legs
Mesothorax
Has the forewings & the second pair of walking legs
Metathorax
Attaches to the abdomen and has the hindwings and the large jumping legs

15. The Grasshopper: external structure…
Abdomen:
The segments are made up of upper and lower plates of exoskeleton joined by a tough but flexible sheet of exoskeleton
The entire grasshopper is covered by a waxy cuticle to slow water loss