THE GRASSHOPPER
The grasshopper or locust is one of the most ancient plagues of
cultivated crops. From the earliest time they have destroyed crops.
During Moses' sojourn in Egypt they were so destructive as to cause
severe famine and various other references to their destructive work are
to be found in the early writings. Since those early days, just think of
the crops that have disappeared between the greedy jaws of grasshoppers!
In our own country it has not been many years since the sun was darkened
for days by clouds of grasshoppers as they settled down from the Rocky
Mountains upon the growing crops in the neighboring states. One day a
field might have a promising crop and by the next day it might be left
as bare as a dry stubble field in August. Those days of great
destruction in America have largely passed but each year the active jaws
of "hoppers" devour a handsome fortune.
[Illustration: Common differential locust or grasshopper; a, egg nests
underground; b, young nymph; c, d, older nymphs; e, adult grasshopper;
f, nymph feeding on grass. This shows development with incomplete
metamorphosis.]
In the same order with the grasshoppers come the crickets, katydids,
rear-horses, devil's darning-needles or walking-sticks, and cockroaches.
The grasshoppers are most troublesome, however. They deposit eggs in the
ground and in other protected places. In the spring these hatch into
young "hoppers" scarcely larger than a pin head at first. Throughout the
early summer these small fellows feed and increase in size. They burst
their old skins and crawl out of them a number of times as they grow
larger. Toward fall they become full grown with four strong wings and
very powerful hind legs for jumping. In this condition most of the
common grasshoppers will be found in the fall when the rural schools
open.
FIELD STUDIES
The small so-called red-legged grasshopper is always most abundant in
the fall and for this reason we have selected it for our studies. It is
about an inch long, olive-brown in color with the ends of the hind legs
bright red. It is found everywhere in pastures, meadows and along
country roads. Approach one of them in the field and see what happens.
How does it get away? When disturbed, how far does it go? Does it hide
in the grass when you try to catch it? Observe one that has not been
disturbed. Where do you find it; on the ground or on plants? How does it
move about when not scared? Watch carefully and see what plants it feeds
on. How does it go about it? What do you find feeding on grasshoppers?
How does a turkey catch them? Have you ever seen a dull colored fly,
which inhabits dry paths and which flies with a humming sound like a
bee, feeding on grasshoppers? These are called "robber-flies" or
"spider-hawks" and they destroy thousands of grasshoppers.
BREEDING CAGE OBSERVATIONS
After you have learned all you can about the habits of the grasshopper
in the field, catch a few of them and take them home and put them in a
glass fruit jar. Collect green leaves for them and watch them feed.
Watch their method of feeding closely and see how it differs from that
of a horse or a cow. How do they move about in the jar? Which legs are
used in walking? What do they do with the jumping legs while walking? Do
they use their wings at all while in the jar? Watch them wash their face
and feet after feeding. Give them leaves of different plants, especially
of field and garden crops and determine which they like best. Can you
find any plant which they will not eat? Find out how fast they feed and
considering the life of any one individual to be 200 days, calculate the
number of grass blades each individual may eat. Are the feelers used
while in the jar, and if so for what purpose?
STUDY OF SPECIMEN
Take a grasshopper from the jar and examine it carefully. Count the
number of legs, wings and joints in the body. How many joints in the
legs? Examine the tip of the foot for a soft pad and on either side of
it a strong hook. What are these used for? What are the sharp spines on
the side of the hind-legs for? Examine the side of the body and see if
you can find the small breathing pores. How do the legs join the body?
Where are the wings attached? How broad are the wings as compared with
the body? How are they folded? Are the two pairs of wings alike? Which
is used most in flying? Is the head firmly attached to the body? Examine
the large eyes; where are they found? Will grasshoppers bite you while
handling them? What is the brown juice which escapes from the mouth when
disturbed? How long are the feelers as compared with the body? Can you
tell the males from the females? What is the distinction? Do they ever
make music? Examine for all the foregoing points and write a brief
report covering these. Make a careful drawing of a grasshopper from one
side; also make an enlarged drawing of the face of a grasshopper and
name the parts.