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Order: Orthoptera
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Common Name--Grasshoppers, Crickets, and Katydids
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Names
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The order Orthoptera is pronounced " or-THOP-ter-a".
This scientific name stems from the Greek words "orthos",
which means straight, and "ptera", which means wings.
The order name refers to the relatively long and straight front
wings of many species.
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Grasshoppers get their common name from their hopping ability and
their eating of grass and other plants. Some species of grasshoppers
that mass together in large numbers and migrate are called locusts.
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There are many different kinds of crickets. The brown house
and field crickets are the ones familiar to most people. Other
crickets include mole crickets, which burrow in the soil; camel
and cave crickets, which are wingless and hump-backed; and tree
crickets, which live in bushes and trees.
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Katydids get their name from the way their songs sound.
Some katydids have been called long-horned grasshoppers because
of their long and slender shape. However, all katydids are more
similar and related to crickets than grasshoppers.
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Diversity
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There are about 12,500 species of Orthoptera found around the
world. An estimated 7,000 more species have never been named
and described. The United States and Canada have almost 1,100
species, of which about 600 are grasshoppers.
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Habitats
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Most Orthoptera are found in grassland areas because of the types
of plants found in open fields. Many species of crickets and
katydids that feed on trees are found in forests. Camel crickets
are found often in dark moist places such as cellars and
under logs and stones, and some even are found in caves. Pygmy
mole crickets occur along the shores of streams and ponds where
they burrow in the sand and soil. A few species of Orthoptera
associated with aquatic plants have adaptations for swimming freely
in water or skating over the surface film of water.
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Form and Function
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Rotate a Grasshopper 360 degrees
1.7mb Quicktime VR File
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Most Orthoptera are between one-half to three inches long, but
some can be as long as six inches. They are generally elongated
and cylindrical and have a leathery exterior. The mouth parts
are designed for biting and chewing. The enlarged hind legs are
the most conspicuous feature of both adults and nymphs. The hind
femur is filled with muscle to enable jumping very high and far.
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Two pairs of wings are usually present in adults, but sometimes
the wings are short or even absent. The front wings are usually
narrow and thickened, whereas the hindwings are broad and membranous.
The hind wings, which have many veins, are folded like
a fan under the front wings when the orthopteran is not flying.
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Some grasshoppers have hindwings colored with yellow, orange,
reds, green, or blue. Other Orthoptera have more subdued colors,
such as various shades of browns and greens. Some species of
katydids, which usually are green, have a genetic variation that
results in individuals with bright pink bodies and wings.
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Grasshoppers are very different from crickets and katydids.
Grasshoppers have antennae that are much shorter than the length
of their body. Grasshoppers make sound by scraping a row
of pegs on their hind legs against their wing or body or by snapping
their hind wings while flying. The grasshopper's hearing organ
is a large membrane, or tympanum, on the first segment of its
abdomen.
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Crickets and katydids have very long antennae, usually longer
than their body. Crickets and katydids create sounds by rubbing
a scraper on one forewing against a file on the other front wing.
The hearing organ of crickets and katydids is located inside
a slit on their front legs. Listen to some cricket sounds.
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Mole crickets (Gryllotalpidae and Tridactylidae) have front legs
that are modified for digging in the soil. Each front leg resembles
a shovel or the foot of a mole.
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Life Cycle
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Orthopterans have incomplete metamorphosis (egg-nymph-adult). Female
grasshoppers usually lay their eggs in the soil. Katydids
and crickets lay their eggs in many places including the soil,
in stems of plants, and in bark of trees.
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Nymphs are very similar to the adults, except they are smaller
and lack fully developed wings. The nymph goes through several
molts (generally five), gradually developing into an adult.
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Different species of Orthoptera have different songs for attracting
mates. It is common to hear the different songs of four or five
species at the same time during the night. The male is usually
the one who makes the sound to attract the a female of the same
species. The sounds are produced by rubbing body parts together,
a process known as stridulation. Some species have drums or
resonating chambers associated with their wings or abdomens to
further amplify the sound.
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Food and Feeding Habits
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Most orthopterans are plant feeders and have chewing mouth parts
designed for feeding on leaves. Some eat only certain plants,
such as grasses, whereas others will eat just about anything that
is green. Mole crickets, which live in the soil, feed on roots
of plants.
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Some camel crickets are predators, and they come out at night
to feed on other insects. Leaf-rolling crickets make silk with
their mouths to tie a leaf into a roll in which they hide during
the day. However, at night they come out of their leaf-roll
to feed on aphids and other insects.
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Common crickets, such as the house cricket and field cricket (Gryllidae),
will feed on plant and animal matter. These feeding habits, similar
to those of human beings, are termed "omnivorous."
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Natural Enemies
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Natural enemies of Orthoptera include birds, mammals, amphibians,
reptiles, spiders, insects, mites, fungi, nematodes and even bacteria.
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Tachinid flies (Tachinidae) and flesh flies (Sarcophagidae) are
parasites of Orthoptera. When the eggs of the fly hatch, the
developing maggots eat their way into the body of the grasshopper
or cricket.
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Grasshopper egg masses in the soil are attacked by larvae of some
bee flies (Bombyliidae), blister beetles (Meloidae), and ground
beetles (Carabidae). When the soil is wet, fungi in the soil
also can kill the eggs.
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Some wasps use Orthoptera as food for their young. Some solitary
wasps (Sphecidae) provision their nests with paralyzed crickets
as food for their larvae. The nest of a single wasp may store
as many as 18 crickets in the nest cells of the developing young.
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Olympic Feats and Other Strange Facts
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The Rocky Mountain grasshopper, Melanoplus spretus, was
a plague in the American mid-west during the 1800's. Swarms contained
millions of grasshoppers. This migratory locust now is considered
extinct as it has not been seen since the early 1900's.
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During the late 1800's in the United States, swarms of locusts
sometimes traveled 1500 miles or more and could do so at a rate
of 20 miles a day.
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A law was passed in Kansas in 1877 that required able-bodied men
between the ages of twelve and sixty-five to assemble to fight
locusts. This was known as the "grasshopper army."
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Grasshoppers in the genus Dicthyphorus secrete bubbles
of a blistering fluid to protect themselves from certain predators.
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It is possible to obtain a close estimate of the outside temperature
in Fahrenheit degrees by listening to the chirps of a Snowy Tree
Cricket, Oecanthus niveus. The following formula, known
as Dolbear's Law, is used for finding the temperature:
T=50+[(n-40)/4].
"T" is the temperature and "n" is the number
of chirps per minute. Count the number of chirps per minute,
subtract 40, divide this number by four, and the addition of 50
will give you the temperature. There are other formulas for
other species that have different songs. The formula for the
Katydid, Cryptophyllus perspicalis, is:
T=60+[(n-19)/3].
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Some katydids are shaped and colored in such a way as to look
like a leaf, either a green leaf complete with veins or a dried,
crumpled leaf. As many leaves have spots of damage from disease
and insect feeding, the wings of some katydids also mimic these
imperfections in the leaf.
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The Ant cricket (Mymecophilus acervorum) is found only
in certain types of ant nests. This cricket licks the ant's
body to feed on its secretions.
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The Good and The Bad
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Some Orthoptera have beneficial uses. Common crickets (Gryllidae)
are reared in large numbers and used for fish bait. Migratory
locusts, which can be serious pests, are eaten by many people
in Africa, and there are festivals associated with the coming
of a grasshopper swarm. They have also been dried and fed to
poultry for a highly nutritious feed.
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Grasshoppers and crickets have long been used in art and literature,
and Jiminy Cricket has become a well-known character. Grasshoppers
have used as models for weather vanes and crests in England, and
crickets have been considered symbols of contentment.
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Crickets have been kept for their singing and fighting ability
in China and Japan. Cricket boxes for these pets were made from
bamboo or metal and often were ornately decorated. Imitations
of these cricket boxes are sold in the United States where they
are used for decoration or storing small things. More information
on the Chinese cricket culture can be found in the Cultural
Entomology Digest.
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Many Orthoptera are serious pests of vegetable and grain crops.
The desert locust (Shistocerca gregaria) is one of the
most destructive insects in the world. These grasshoppers are
found in Africa, India, and the Middle East, and a large swarm
of them can eat 3000 tons of green plants a day. These crop
losses have resulted in severe famines which have caused many
deaths from starvation. The desert locust is the same grasshopper
that plagued the people in Egypt in Biblical times.
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Taxonomy
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Families of North American Orthoptera
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Tetrigidae (pygmy grasshoppers)
Eumastacidae (monkey grasshoppers)
Tanaoceridae (desert long-horned grasshoppers)
Acrididae (short-horned grasshoppers)
Tridactylidae (pygmy mole crickets)
Tettigoniidae (long-horned grasshoppers, katydids)
Gryllacrididae (camel crickets, cave crickets, and others)
Gryllidae (crickets)
Gryllotalpidae (mole crickets)
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Selected References
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Evans, H. E. Life on a Little-known Planet. New York: E.P.Dutton
& Co., Inc., 1966.
Blatchley, W.S. Orthoptera of Northeastern America. Indianapolis, The
Nature Publishing Co., 1920.
Helfer, J.R. How to Know the Grasshoppers, Cockroaches,
and their Allies. Pictured Key Nature Series. Dubuque, Iowa: Wm. C.
Brown Co., 1972.
Borror, D.J. and R.E. White. A Field Guide to the Insects of
America North of Mexico. Boston: Houghton Mifflin Co.
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Links
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For an extensive list of Hemiptera Web sites, go to the Links Component of the module.
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Picture Credits
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Dr. Ross E. Hutchins (Deceased)
Mississippi Entomological Museum
Lubber grasshopper, Romelea guttata. This species cannot fly.
Tree cricket, Oecanthus sp.
Katydid, Amblycorypha sp.
Adults and nymphs of camel crickets
American grasshopper, Schistocerca americana, in flight
Tympanum (at arrow) on first segment of grasshopper's abdomen
File on left wing and scraper on right wing of katydid
Katydid with tympanum on each foreleg
Mole cricket with front legs modified for burrowing
Nymph of grasshopper
Chewing mouthparts of grasshopper
Leaf-rolling circket, Camptonotus carolinensis, tying a leaf with silk
House or field crickets, Gryllus sp.
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