Facts about grasshoppers and crickets
How Grasshoppers Jump
(http://biology.st-and.ac.uk/sites/jumping/)
A good jump means that the legs must push against the ground with high force,
and high speed.
To be precise, a typical grasshopper weighing 2-3 gm will thrust against the
ground with a force
which peaks at about 30 gms when the legs are half extended, to give it a final
take-off velocity
of about 3 m.s-1.
Note how in the good jump there is a slight delay between the initial crouch and
the actual jump.
The ultimate source of this push comes from the contraction of the muscles
inside the leg.
To get a good jump requires two things.
First, the legs have to thrust on the ground with a lot of force.
If the thrust is too low, the animal doesn't get a fast enough take-off and it
doesn't jump very
far.
Second, the legs have to develop this force quickly.
If the thrust builds up too slowly, the legs will extend before the thrust
reaches its maximum.
Once the grasshopper is standing on tip-toe, it can't thrust against the ground
any more.
Swarms
Most grasshoppers lead relatively blameless lives, causing little harm to crops
or gardens.
However, some species of grasshoppers lead a "Jekyll and Hyde" existence, and
can change into a
very damaging form indeed, in which they congregate in huge swarms that can do
severe damage to
crops. These swarming grasshoppers are called locusts. There are more than
20,000 species of
grasshoppers known to science, but only about a dozen of these form damaging
swarms.
Locusts have two "phases" of existence. When food is plentiful, they exist in
the solitary form.
In this form they act just like other grasshoppers - they have no tendancy to
form swarms, and
they do little damage. They can exist in the solitary form for many generations.
However, if food
becomes scarce, they switch to the gregarious form. This form actually looks
different to the
solitary form, to the point that one would think it was a completely different
species. However,
it is not the appearance change which is the problem, it is the change in
behavior. Locusts in
the gregarious phase really like each others company, they join together in huge
enormous (we're
talking billions of locusts, covering hundreds of square miles in the worst
cases) and eat just
about every green thing they encounter.
One swarm in 1988 covered an area of 75 x 15 miles, contained (about) 150
billion locusts and was
estimated to be eating 300,000 tons fresh green food per day.
Singing
A more attractive feature of some grasshoppers is their ability to sing. It's
the males that
sing, and they do it to attract female mates, or to warn off other males. There
are two different
mechanisms for singing. In one (used by short-horned grasshoppers), there is a
comb-like
structure with a row of teeth on the inside of the hind leg, which gets rubbed
against a ridge on
the wing (a bit like running a stick along a fence very quickly). This produces
a "chirp" sound.
In the other mechanism (used by crickets and long-horned grashoppers) there is
again a
comb-and-ridge mechanism, but the structures are on the left and right
forewings, which rub over
each other.
Short horned grasshoppers have ears in the sides of the abdomen. Long-horned
grasshoppers and
crickets have ears in the knee-joints of their front legs.
Amazing fact. The extensor muscle from the back leg of an adult female locust (Schistocerca
gregaria) can develop a force of up to 1.4 kg. This means that the muscle from
one back leg of a
grasshopper (admitedly quite a large one) can lift almost a bag-and-a-half of
supermarket sugar!
(http://www.ris.net/~lawnman/hopfact.html)
excellent site for info but music needs a health warning
Amazing Grasshopper Facts
A Grasshopper is an amazing insect that can leap 20 times the length of its own
body. If you or I
could do that, we would be able to jump almost 40 yards! While I wouldn't have a
problem with
being able to jump so far, I think landing would be a problem.
Grasshoppers can be found almost everywhere in the world, except for the colder
regions near the
North and South poles. They live in fields, meadows, and just about anywhere
they can find
generous amounts of leaves to eat. (which they do with a passion). Some types of
grasshoppers
will only eat certain types of plants. Others will eat any type of plant they
can find.
Grasshoppers can destroy entire crops of alfalfa, clover, cotton, corn and other
grains, causing
millions of dollars in crop damages every year. (This is probably a good reason
to eat
grasshoppers instead of corn).
When a grasshopper is picked up, they "spit" a brown liquid which is known by
most kids and
adults as "tobacco juice". (Maybe they someday hope to join a baseball team).
Some scientists
believe that this liquid may protect grasshoppers from attacks by insects such
as ants.
http://www.ivyhall.district96.k12.il.us/4th/kkhp/1insects/grshprfax.html
Cricket facts from the Minnesota pollution control agency
Crickets Make Good Thermometers
Did you know that you can tell the temperature by counting cricket chirps?
Here's how you do it. Go outside at dusk or at night and find a chirping
cricket. Count the number of chirps it makes during a 15-second period. Then,
add 40 to the number of chirps. The total will be pretty close to what the
actual temperature is in Fahrenheit.
even more amazing: subtract the year you were born from the current date; then add the current temperature in Fahrenheit; subtract 40 and remember the result; count the number of times you hear a cricket chirping in a 30 second period; divide that figure by 2; subtract the result from your previous total and you are left with- your age !
Crickets eat just about anything -- they're omnivorous.
You'll find them in your garden eating rotten tomatoes and other debris. They'll
even eat other insects, including each other. They can also get into your house
and eat paper, clothes, or anything else they feel like eating.