Lesson LXXX

The Red-Legged Grasshopper

Leading thought—The grasshopper feeds upon grass and other herbage and is especially fitted for living in grassy fields. Its color protects it from being seen by its enemies the birds. If attacked, it escapes by long jumps and by flight. It can make long journeys on the wing.

Method—The red-legged grasshopper (M. femur-rubrum) has been selected for this lesson because it is the most common of all grasshoppers, though other species may be used as well. The red-legged locust, or grasshopper has, as is indicated by its name, the large femur of the hind legs reddish in color. Place the grasshopper under a tumbler and upon a spray of fresh herbage, and allow the pupils to observe it at leisure. It might be well to keep some of the grasshoppers in a cage similar to that described for crickets. When studying the feet, or other parts of the insect requiring close scrutiny, the grasshopper should be placed in a vial so that it may be passed around and observed with a lens. Give the questions a few at a time, and encourage the pupils to study these insects in the field.

Observations—1. Since a grasshopper is such a high jumper, discover if you can how he does this “event.” Which pair of legs is the longest? Which the shortest? How long are the femur and tibia of the hind leg compared with the body. What do you think gives the braided appearance to the surface of the hind femur? What is there peculiar about the hind femur? Note the spines at the end of the tibia just behind the foot.

2. Watch the grasshopper prepare to jump and describe the process. How do you think it manages to throw itself so far? If a man were as good a jumper as a grasshopper in comparison to his size, he could jump 300 feet high or 500 feet in distance. Why do you think the grasshopper needs to jump so far?

3. As the grasshopper climbs up the side of a tumbler or vial, look at its feet through a lens and describe them. How many segments are there? Describe the claws. How does it cling to the glass? Describe the little pad between the claws.

4. Look the grasshopper in the face. Where are the compound eyes situated? Can you see the tiny simple eyes like mere dots? How many are there? Where are they? How long are the antennæ? For what are they used?

5. How does a grasshopper eat? Do the jaws move up and down or sidewise? What does the grasshopper eat? How many pairs of palpi can you see connected with the mouth-parts? How are these used when the insect is eating? When there are many grasshoppers, what happens to the crops?

6. What do you see just back of the grasshopper’s head, when looked at from above?

7. Can the grasshopper fly as well as jump? How many pairs of wings has it? Does it use the first pair of wings to fly with? How does it hold them when flying? Where is the lower or hind pair of wings when the grasshopper is walking? How do they differ in shape from the front wings?

8. Note the abdomen. It is made of many rings or segments. Are these rings continuous around the entire body? Where do their breaks occur? Describe the movement of the abdomen as the insect breathes. Can you see the spiracles or breathing pores? Lift the wings, and find the ear on the first segment of the abdomen.

9. If you seize the grasshopper how does it show that it is offended?

10. How does the grasshopper perform its toilet? Describe how it cleans its antennæ, face and legs.

11. What becomes of the grasshoppers in the winter? Where are the eggs laid? How can you tell a young from a full-grown grasshopper?

12. Do all grasshoppers have antennæ shorter than half the length of their bodies? Do some have antennæ longer than their bodies? Where are the long-horned grasshoppers found? Describe how they resemble the katydids in the way they make music and in the position of their ears.

Supplementary reading—Chapters XVI-XVIII in Grasshopper Land, Morley.