1. Ch. 40 Insects
Most diverse and largest number of species of any class of organism.
They were present on earth before the dinosaurs, over 300 million years ago.
Differences from other arthropods
1. 3 body segments  head, thorax, abdomen

2. 2. Head has 1 pair of antennae
3. Thorax has 3 pairs of legs & 1 or 2 pair of wings.
4. No wings or legs attached to the abdomen.

3. Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta (700,000 + species named)
What makes insect so successful?
Lots of them – adapt very well
Great diversity – several types
Reproduce rapidly
Small size & ability to fly (most)

4. Benefit of insects?
1. Pollination – plants can’t reproduce without insects. We need plants to survive.
2. Food – for other animals. Several animals rely on insects as a source of food.
3. Industrial uses – silk & honey
What is the study of insects called? (E.C)
Entomology

5. Grasshopper  External Structures
3 Body Parts:
1. Head
Labium – grasps the food ( bottom lip)
Mandible – chews the food (jaws)
Labrum – holds the food (upper lip)
Maxilla – extra jaws
2. Thorax
3 pairs of legs (6 total)
2 pair of wings usually

6. 3 parts to the thorax
1. Prothorax – pair of walking legs
2. Mesothorax. – pair of walking legs
3. Metathorax – pair of jumping legs
Forewings are attached to the mesothorax
Hindwings are attached to the metathorax

7. 3. Abdomen
Spiracle – for respiration
Tympanum – for hearing (eardrum)
Ovipositors – holds it eggs

8. GrasshopperInternal Structures
Digestive System
What do grasshoppers eat?
What are the mouth parts?
Food passage: esophaguscrop (storage) gizzard (grind) midgut (digested) hindgut (rectum & colon)  out the anus

9. Circulatory System
Open Circulatory System
An aorta is a large vessel that carries the blood on the dorsal side.
2 Hearts along the aorta

10. Respiratory System
No lungs or gills
Use spiracles – openings along the abdomen
The spiracles lead to the trachea
Nervous System
Brain connected to a ventral nerve cord
Has simple and complex eyes

11. Have antennae
Tympanum for sensing sound
Reproductive System
The male deposits sperm into the seminal receptacle, which stores the sperm.
The female uses its ovipositors to deposit her eggs in the ground.

12. Types of Metamorphosis
Incomplete Metamorphosis
1. Egg
2. Nymph – immature form of an adult
3. Adult – able to reproduce (wings)

13. Complete Metamorphosis
1. Egg
2. Larvae – catepillar stage
3. Pupa – cocoon protects the pupa
4. Adult – emerges from the pupa (butterfly)

14. Defenses of Insects What ways do insects use defenses?
1. Stinger or bite – bee, wasp, ants
2. Camouflage – blend into their surroundings.
Ex. Grasshopper, praying manthesis
3. Warning coloration – alert other animals that the insect might be poisonous.

15. Insect Behavior
Division of Labor among Bees
1. Worker bee – female bees, most abundant. (8,000) - sterile
2. Drone – male bees (100)
3. Queen bee – the only fertile female
CHARACTERISTIS OF EACH BEE

16. The worker bee produces royal jelly to feed the queen bee
The worker also secretes wax to make the hive.
The produces a pheromone called queen factor, which makes the other females sterile.
Round Dance – tells the other bees food is within 50 meters
Waggle Dance – tells the other bees food is greater than 50 meters.