What are the various kinds of locomotion
a grasshopper can use? Which are used in the vivarium
and which when free in the laboratory?
Which legs are used in jumping? How are these
legs especially adapted to this, in length, structure and
direction? Could a grasshopper jump if the third pair of
legs were arranged like the other two pairs? Why?
How is the animal able to cling to grass stems and
not slip down? What is the direction of the body in
relation to the stem or grass blade?
What is the position of the wings when at rest?
when in use? How do the hind wings fold? How are
the principal veins of the wings arranged to permit or
facilitate this folding?
Contrast the fore and hind wings with respect to
thickness, size, and use.
To which somites of the thorax are the wings attached?
Nearer which surface, the dorsal or ventral? Why?
Discover all you can about the uses
of the antennæ by carefully observing grasshoppers at
rest, feeding, jumping and crawling, approaching an object
or another grasshopper, etc.
How many compound eyes has the grasshopper?
How many simple eyes? Where are they located?
Examine a preparation of the compound eye with the low power or
as demonstrated with the stereopticon. What is the shape of an eye
element of the compound eye? About how many eye elements are
there in a compound eye?
Do grasshoppers eat and drink while in
captivity? Put a fresh bunch of grass which has been
sprinkled with water in a vivarium with grasshoppers that
have had no food or drink for twenty-four hours and watch
results.
What is the position of the grasshoppers in feeding?
In what direction do the jaws move in feeding? Compare
this with the direction of movement of your own
jaws. What is the use of the palps? What do you think
is the use of the "molasses" or saliva that flows from the
mouth?
Describe the breathing movements of
a grasshopper and explain the relation of the movements
to inhalation and exhalation of air.
Find the exact location and number of spiracles on
the abdomen. There are two pairs of spiracles on the
thorax. Find them. How do the spiracles prevent the
entrance of dust?
Describe a trachea as seen in a mounted preparation with the aid of
a microscope or stereopticon.
Explain how the colors of the grasshopper
may be protective or useful when at rest in its
natural habitat and when in flight.
Does the shell cover the entire body? What are
the advantages of such a covering? A shell is likely to
hinder activity, sensitiveness, and growth. How are such
disadvantages overcome in this case?
What senses are probably most relied upon to
detect approaching danger? Give evidence to support
your answer.
What is the position of the hind legs when at rest?
What relation has this to safety?
Describe the ovipositors
and the probable method of their use. Describe
the egg packets of grasshoppers, if discovered. About
how many eggs in one? (They are sometimes seen
against the glass sides of the vivaria.)
If you have young grasshoppers of various ages,
arrange a set of them in what seems to you to be the order
of their development. How do young grasshoppers differ
from adults? What changes take place as they develop?
What kind of metamorphosis is this?
Summary of Important Points in the Study of the Grasshopper
How many and what distinct regions of the body
are there?
How many antennæ? Compare their length with that
of the body. What other sense organs did you discover?
How many legs? For what specially adapted? How?
How many wings? What is their resting position?
How do the fore wings differ from the hind wings? How
do the hind wings fold?
To what kind of feeding are they adapted, biting or
sucking the food? How many and what sets of mouth
parts are there?
How is air necessary for respiration obtained?
In what various ways are grasshoppers fitted for life
in meadows and weed plots?