Mr and Mrs Smith's Life Science

grasshopper2.gif (2242 bytes)Grasshopper Observation and Dissection

   Outside Observation: Table 1 Structure of the Grasshopper

Body Part How Many?        Function: What does it do?
Simple Eyes                                                                         
Compound Eyes    
Front Legs    
Middle Legs    
Back Legs    

Grasshoppers are members of the phylum Arthropoda.  Grasshoppers belong to the phylum arthropods and to the class insects.  There are more than 900,000 species of insects.   They are mainly land animals and occupy almost every environment on land.  The development of wings gave grasshoppers advantages over other land invertebrates. They could spread out into new areas, they could search larger areas for food, and they were able to fly away and escape from predators.

Grasshoppers have an exoskeleton composed of chitin.   They have three pairs of jointed legs. The front  pair are used for walking, climbing, and holding food. The  middle pair are used for walking and climbing.   The back pair of legs are used for jumping. There are three distinct body regions, the head, the thorax, and abdomen.  The head is used for eating and sensing, the thorax is used for


movement, and the abdomen has the digestive and reproductive organs. Two pairs of wings are attached to the thorax.  Grasshoppers have one pair of antennae that is used for sensing,  one pair of large compound eyes that detect movement, and three simple eyes that detect light and dark. Tympanum, or eardrums, on the thorax are used for hearing.  The grasshopper's spiracles and air tubes provide a way for getting oxygen into the body and removing waste gasses from the body.   Grasshoppers lay a large number of eggs, and the eggs hatch very quickly.   This allows the grasshopper population to increase rapidly.

Part A Outside Observation

1. Locate the head, thorax, and abdomen.

2. Observe the head.  Locate the two compound eyes and the three simple eyes.

3. Identify the mouth parts. Use your magnifying glass to locate:

     Labrum: hinged upper lip that holds food

     Mandibles: crushing jaws

     Maxillae: chew and taste food

     Labium: hold food while being chewed

4. Locate the typamum, or eardrums, on the thorax.

5. All insects have six legs. Locate:

     Front Legs     Middle Legs      Back Legs

6. Locate the two pairs of wings.

7. Find the tiny openings along the abdomen called spiracles. 
    These are the breathing pores through which oxygen enters and carbon dioxide leaves.

8. A female grasshopper has a much longer abdomen than a male.
    It ends in a four-pointed tip called an ovipositor through which eggs are laid.

grasshopper2.gif (2242 bytes)Grasshopper Dissection and Internal Observation    

The grasshopper's digestive tract is specialized to eat plant tissue.  The mouth parts  hold, crush, and chew the food before it passes into the mouth. From the mouth the food passes through the esophagus into the crop.   The food is stored in the crop.  Next, food moves into the gizzard, where teeth made of chitin grind it up further.  Food then moves into the intestines where glands digest the food. and other structures absorb the digested food.  Undigested food then goes to storage in the rectum, and then is eliminated out the anus.

Part B Internal structure

9. Remove the three right legs.


Insert the point of your scissors under the top surface of the last segment of the abdomen and make a cut to the right of the mid-dorsal line all the way to the head. Be careful not to cut the organs underneath.       



In front of the thorax, cut down
the right side to the bottom of the grasshopper.

Cut down between the next to the  last and last abdominal segments.


12. Remove the exoskeleton from the right side of your grasshopper.

13. Locate the large dorsal blood vessel that runs down the grasshopper's body.


14. Remove ovaries from the grasshopper.  These look like maggots or brown rice.
     Eggs are produced in the ovaries.

15. Remove the muscles of the abdomen.  Can you see the air tunes?
16. Carefully cut away muscle and tissue to expose the digestive system.

17. Locate the parts of the digestive system:

     Mouth, Esophagus, Crop, Gizzard, Stomach, Intestine, Rectum, Anus




                                  Table 2 Internal Structure of the Grasshopper

Body Part        Function: What does it do?
Air Tubes                                                                       


Name the three parts of a grasshopper's body.  

1. _______________     2. _______________     3. _______________

4. What eyes does a grasshopper use to detect moving objects? _______________

Name four functions of the mouth parts of the grasshopper.

5. _______________     6. _______________     7. _______________     8. _______________

Name two functions of the head.

9. ____________________     10. ____________________

11. Which legs are used for jumping? _______________

12. Which legs are used for walking, climbing, and holding food? _______________

13. Which legs are used for walking and climbing? _______________

14. Can you drown a grasshopper by holding its head underwater? ______

15. The grasshopper belongs to the Phylum ________________

16. The grasshopper belongs to the Class _______________

17. Which of the 5 Kingdoms does the grasshopper belong to? _______________

18. Name one reason a grasshopper population may increase rapidly. ___________________

Label the parts of the grasshopper's body.