Grasshoppers

views updated May 21 2018

Grasshoppers

Classification, distribution, and habitat

Leaping

Size and color

Body temperature

Defense

Courtship and mating

Reproduction and development

Grasshoppers and the environment

Resources

Grasshoppers are plant-eating insects characterized by long hind legs designed for locomotion by jumping. Like all insects, the body of grasshoppers is divided into three main parts: head, thorax, and abdomen. On the head are two antennae for feeling and detecting scent, and two compound eyes comprised of many optical units called facets, each of which is like a miniature eye. The chewing mouthparts comprise two sets of jaws that move from side to side. The sides of the mouth have two palps, tiny appendages for feeling and detecting chemicals, which aid in food selection. There are three pair of legs and two pairs of wings attached to the thorax, although some species are wingless. At the tip of the abdomen are two appendages called cerci, and the external reproductive organs. Females have an ovipositor at the end of the abdomen through which the eggs are laid. Grasshoppers develop by incomplete metamorphosis, passing from egg, to a small wingless larval stage through several molts, to the mature adult.

Classification, distribution, and habitat

Grasshoppers belong to the insect order Orthoptera and the suborder Caelifera. The family Acrididae includes more than 8,000 species of grasshoppers and locusts distributed worldwide. Grasshoppers are found in almost all types of habitat including the tropics, temperate grassland, rainforest, desert, and mountains. If adverse conditions prevail, some species migrate in huge numbers to maximize survival. Grasshoppers feed on grass, leafy plants, and bushes. Some species eat only particular food plants, but most species broaden their food base following depletion of their preferred food.

Maintaining appropriate moisture content in the body is achieved primarily through food selection. All species of grasshopper consume both wet and dry food; however, a hydrated insect will choose leaves with low water content, while a dehydrated one selects leaves higher in moisture. Captive grasshoppers will drink water directly when food moisture drops below about 50%.

Leaping

Leaping is so advantageous that some grasshopper species have lost the ability to fly. Grasshoppers can repeatedly jump many times their body length without tiring, attaining speeds up to ten times greater than that of a running insect. Their muscular back legs allow powerful propulsion. The legs have a muscular femur (thigh), a long, slender tibia (shin), and a five-jointed foot with claws. Before jumping, the grasshopper flexes its rear legs and projects itself through the air with an explosive kick, sometimes using its wings to help it glide. Grasshoppers move mainly by leaping and seldom fly long distances.

Size and color

Male grasshoppers are smaller than females, and size varies greatly between speciesfrom a length of 0.4 in (1 cm) to more than 5.9 in (15 cm). The large Costa Rican grasshopper (Tropidacris cristatus ) has a 9.9 in (25 cm) wingspan and weighs more than 1 oz (30 g). Colors range from the drab shades of the field dwellers to the brilliant hues of some rainforest species. In some instances, males and females are colored differently.

Body temperature

Although grasshoppers have a body temperature that ranges with the environmental temperature, the actual body temperature is important since it can affect movement, digestion, food consumption, water retention, egg/nymph survival rate, life expectancy, mating, and habitat selection. The preferred temperature range is 86-112°F (30-44°C). Because grasshoppers normally produce little body heat, they thermoregulate (maintain appropriate body temperature) by using heat gained from the environment. Long, thin species increase body heat by exposing their sides to the sun. Broad, flat grasshoppers turn their back perpendicular to the suns rays. Crouching allows heat absorption from a warm surface into the abdomen, while stilting (extending the legs) cools the insect by lifting it off a warm surface and permitting air to circulate around its body.

Defense

Grasshoppers are eaten by a number of vertebrate and arthropod predators. Defense mechanisms include leaping and camouflage (blending in with their environment). For example, the grass-dwelling Cylindrotettix of Brazil changes the color of its body from straw-colored in the dry season to green after the rains. Larger species such as Agriacris trilineata of Perus rainforests may use physical defense, kicking predators with powerful hind legs equipped with long spines that can draw blood. Other species use startle tactics. The Mexican Taeniopoda auricornis, a tiny black-and-white grasshopper, flashes glorious crimson wings to startle and scare off predators.

Chemical deterrents, such as the regurgitation and defecation of sticky, obnoxious-smelling fluids, are employed by many grasshopper species. A few species produce a stinking glandular excretion that effectively repels predators as large as geckos, jays, domestic cats, and monkeys. Certain species sequester toxic chemicals from their plant food, making predators who ingest them ill. Most toxic species of grasshoppers have conspicuous vivid warning colors that predators learn to avoid. Some nontoxic species of grasshopper mimic the color of toxic species so that predators also avoid them.

Courtship and mating

Grasshoppers have an amazing ability to identify their mates. Each species has its individual song, produced by rubbing or flicking the lower back legs on the forewings to create either a chirping or a clicking sound (known as stridulation). Females sing more softly than males, facilitating differentiation between both sex and species. Species that make no sound rely on sight and scent to find a mate. Males emit phero-mones, external hormones to attract females, while other species use their excellent eyesight to enable identification by color. The tiny, wingless grasshopper Drymophilacris bimaculata of Costa Rica has a brilliant green body with glimmering gold accents on its head, thorax, and genital areas. The male of this species searches out its mate by drumming its hind legs on its preferred food plant. The female drums back, and the pair identify each other by their unique coloring.

Elaborate courtship routines are performed by males in some species. The American grasshopper Syrbula admirabilis displays 18 individual poses using its wings, legs, and palps. Males of other species may wave brilliantly colored wings when wooing the female, while other species forego courtship altogether.

Mating occurs when the male lights on the females back and may last anywhere from 45 minutes to well over a day. In the species Extatosoma tiaratum, a female mates with several males. Most of the sperm in her genital tract from the first suitor is replaced by the sperm of her next mate. Males therefore mate many times with the same partner and with other females to gain the maximum opportunity to pass on their genes. Males of some species die shortly after mating. The females die after egg-laying, which may last until cold weather begins.

Reproduction and development

Female grasshoppers deposit fertilized eggs in batches in the ground, on the ground, or less commonly, on grass or plant stems. When burying eggs, the female uses four hornlike appendages at the tip of the abdomen, then twists her body and forces her ovipositor into the ground. The desert species Locusta migratoria extends her abdomen from its normal length of 1 in (2.5 cm) to 3.2 in (8 cm) to bury her eggs as deeply as possible.

In tropical species the eggs hatch after three or four weeks, whereas in temperate climates eggs usually undergo diapause (suspended development) over the winter. Eventually, tiny larvae hatch and burrow to the surface, molting immediately to emerge as undeveloped miniatures of the adult (nymphs). They may undergo as many as six molts before reaching maturity at an average age of three months.

Grasshoppers and the environment

Swarming grasshoppers and locusts can be extremely destructive to vegetation. A single swarm

KEY TERMS

Cerci A pair of feelers at the tip of the abdomen.

Diapause A period of delayed development.

Ovipositor Egg-laying organ on the tip of a female insects abdomen.

Palps Tiny appendages near the mouth sensitive to touch and chemical detection or taste.

Pheromone Hormonal chemical excretion used to attract a mate.

Stridulation Chirping, clicking or other audible sounds made by certain insects by rubbing body parts together.

of African locusts (Schistocerca gregaria ) can contain 50 billion individuals, and consume as much food in one day as the daily food intake of all the people in New York, London, Paris, and Los Angeles combined. Clearly, such immense irruptions are capable of causing tremendous damage to agriculture. Insecticides and the introduction of pathogenic fungi deadly to the insects are methods used to try to control such plagues, but this is not always successful. Sometimes, less conventional methods prove effective. In Thailand, Mexico, parts of Africa, and other countries, grasshoppers are edible delicacies, providing important dietary protein. During a locust plague in Thailand, government authorities encouraged citizens to catch the swarming masses. Domestic and commercial crops were saved from complete destruction and billions of grasshopper bodies were sold to restaurants and market places for seasoning, stir frying, and consumption by many a delighted connoisseur.

Resources

BOOKS

Carde, Ring, and Vincent H. Resh, eds. Encyclopedia of Insects. San Diego, CA: Academic Press, 2003.

Chapman, R.F., and A. Joern, eds. Biology of Grasshoppers. New York: John Wiley & Sons, Inc., 1990.

Helfer, Jacques R. How to Know the Grasshoppers and Their Allies. Toronto: Dover Publications, 1987.

Preston-Mafham, Ken. Grasshoppers and Mantids of the World. London: Blandford, 1990.

OTHER

U.S. Department of Agriculture, Agricultural Research Service. Grasshoppers: Their Biology, Identification, and Management <http://www.sidney.ars.usda.gov/grasshopper/> (accessed November 26, 2006).

University of Wyoming: Wyoming Geographic Information Science Center. Field Guide to Common Western Grasshoppers <http://www.wygisc.uwyo.edu/grasshopper/fieldgde.htm> (accessed November 26, 2006).

Marie L. Thompson

Grasshoppers

views updated Jun 27 2018

Grasshoppers

Grasshoppers are plant-eating insects characterized by long hind legs designed for locomotion by jumping. Like all insects, the body of grasshoppers is divided into three main parts: head, thorax, and abdomen. On the head are two antennae for feeling and detecting scent, and two compound eyes comprised of many optical units called facets, each of which is like a miniature eye . The chewing mouthparts comprise two sets of jaws which move from side to side. The sides of the mouth have two palps, tiny appendages for feeling and detecting chemicals, which aid in food selection. There are three pair of legs and two pairs of wings attached to the thorax, although some species are wingless. At the tip of the abdomen are two appendages called cerci, and the external reproductive organs. Females have an ovipositor at the end of the abdomen through which the eggs are laid. Grasshoppers develop by incomplete metamorphosis , passing from egg, to a small wingless larval stage through several molts, to the mature adult.


Classification, distribution, and habitat

Grasshoppers belong to the insect order Orthoptera and the suborder Caelifera. The family Acrididae includes more than 8,000 species of grasshoppers and locusts distributed worldwide. Grasshoppers are found in almost all types of habitat including the tropics, temperate grassland, rainforest , desert , and mountains . If adverse conditions prevail, some species migrate in huge numbers to maximize survival. Grasshoppers feed on grass, leafy plants, and bushes. Some species eat only particular food plants, but most species broaden their food base following depletion of their preferred food.

Maintaining appropriate moisture content in the body is achieved primarily through food selection. All species of grasshopper consume both wet and dry food; however, a hydrated insect will choose leaves with low water content, while a dehydrated one selects leaves higher in moisture. Captive grasshoppers will drink water directly when food moisture drops below about 50%.


Leaping

Leaping is so advantageous that some grasshopper species have lost the ability to fly. Grasshoppers can repeatedly jump many times their body length without tiring, attaining speeds up to ten times greater than the speed of a running insect. The muscular back legs of grasshoppers allow powerful propulsion. The legs have a muscular femur (thigh), a long, slender tibia (shin), and a five-jointed foot with claws. Before jumping, the grass hopper flexes its rear legs and projects itself through the air with an explosive kick, sometimes using its wings to help it glide. Grasshoppers mainly move by leaping and seldom fly long distances.


Size and color

Male grasshoppers are smaller than females, and size varies greatly between species—from a length of 0.4 in (1 cm) to more than 5.9 in (15 cm). The large Costa Rican grasshopper (Tropidacris cristatus) has a 9.9 in (25 cm) wing-span and weighs more than 1 oz (30 g). Colors range from the drab shades of the field dwellers to the brilliant hues of some rainforest species. In some instances, males and females are colored differently.


Body temperature

Although grasshoppers have a body temperature that ranges with the environmental temperature, the actual body temperature is important since it can affect movement, digestion, food consumption, water retention, egg/nymph survival rate , life expectancy, mating, and habitat selection. The preferred temperature range is 86-112°F (30-44°C). Because grasshoppers normally produce little body heat , they thermoregulate (maintain appropriate body temperature) by using heat gained from the environment. Long, thin species increase body heat by exposing their sides to the sun . Broad, flat grasshoppers turn their back perpendicular to the sun's rays. Crouching allows heat absorption from a warm surface into the abdomen, while stilting (extending the legs) cools the insect by lifting it off a warm surface and permitting air to circulate around its body.


Defense

Grasshoppers are eaten upon by a number of vertebrate and arthropod predators. Defense mechanisms include leaping and camouflage (blending in with their environment). For example, the grass-dwelling Cylindrotettix of Brazil changes the color of its body from straw-tone in the dry season to green after the rains. Larger species such as Agriacris trilineata of Peru's rainforests may use physical defense, kicking predators with powerful hind legs ominously equipped with long spines that can draw blood . Other species use startle tactics. The Mexican species Taeniopoda auricornis, a tiny black-and-white grasshopper, flashes glorious crimson wings to startle and scare off predators.

Chemical deterrents, such as the regurgitation and defecation of sticky, obnoxious-smelling fluids, are employed by many species of grasshoppers. A few species produce a stinking glandular excretion which effectively repels predators as large as geckos , jays, domestic cats , and monkeys . Certain species sequester toxic chemicals from their plant food and predators ingesting them become ill. Most of the toxic species of grasshoppers have conspicuous vivid warning colors which predators learn to avoid. Some nontoxic species of grasshopper mimic the color of toxic species so that predators also avoid them.


Courtship and mating

Grasshoppers have an amazing ability to identify their mates. Each species has its individual song, produced by rubbing or flicking the lower back legs on the forewings to create either a chirping or a clicking sound (this is known as stridulation). Females sing more softly than males, facilitating differentiation between both sex and species. Species that make no sound rely on sight and scent to find a mate. Males emit pheromones , external hormones which attract females, while other species use their excellent eyesight to enable identification by color. The tiny, wingless grasshopper Drymophilacris bimaculata of Costa Rica has a brilliant green body with glimmering gold accents on its head, thorax, and genital areas. The male of this species searches out its mate by drumming its hind legs on its preferred food plant. The female drums back, and the pair identify each other by their unique coloring.

Elaborate courtship routines are performed by males in some species. The American grasshopper Syrbula admirabilis displays 18 individual poses using its wings, legs, and palps. Males of other species may wave brilliantly colored wings when wooing the female, while other species forego courtship altogether.

Mating occurs when the male lights on the female's back and may last anywhere from 45 minutes to well over a day. In the species Extatosoma tiaratum, a female mates with several males. Most of the sperm in her genital tract from the first suitor is replaced by the sperm of her next mate. Males therefore mate many times with the same partner and other females to gain the maximum opportunity to pass on their genes. Males of some species die shortly after mating. The females die after egg-laying, which may last until cold weather begins.


Reproduction and development

Female grasshoppers deposit fertilized eggs in batches in the ground, on the ground, or less commonly, on grass or plant stems. When burying eggs, the female uses four horn-like appendages at the tip of the abdomen, and twists her body and forces her ovipositor into the ground. The desert species Locusta migratoria extends her abdomen from its normal length of 1 in (2.5 cm) to 3.2 in (8 cm) in order to bury her eggs as deep as possible.

In tropical species the eggs hatch after three or four weeks, whereas in temperate climates eggs usually undergo diapause (suspended development) over the winter. Eventually, tiny larvae hatch and burrow to the surface, molting immediately to emerge as undeveloped miniatures of the adult (nymphs). These nymphs may undergo as many as six molts before reaching maturity at an average age of three months.


Grasshoppers and the environment

Swarming grasshoppers and locusts can be extremely destructive to vegetation. A single swarm of African locusts (Schistocerca gregaria) can contain 50 billion individuals, and consume as much food in one day as the daily food intake of all the people in New York, London, Paris, and Los Angeles combined. Clearly, such immense irruptions are capable of causing tremendous damage to agriculture. Insecticides and the introduction of pathogenic fungi deadly to the insects are methods used to try to control such plagues, but this is not always successful. Sometimes, less conventional methods prove effective. In Thailand, Mexico, parts of Africa , and other countries, grasshoppers are edible delicacies, providing important dietary protein. During a locust plague in Thailand, government authorities encouraged citizens to catch the swarming masses. Domestic and commercial crops were saved from complete destruction and billions of grasshopper bodies were sold to restaurants and market places for seasoning, stir frying, and consumption by many a delighted connoisseur.


Resources

books

Carde, Ring, and Vincent H. Resh, eds. Encyclopedia of Insects. San Diego, CA: Academic Press, 2003.

Chapman, R.F., and A. Joern, eds. Biology of Grasshoppers. New York: John Wiley & Sons, Inc., 1990.

Helfer, Jacques R. How to Know the Grasshoppers and Their Allies. Toronto: Dover Publications, 1987.

Preston-Mafham, Ken. Grasshoppers and Mantids of the World. London: Blandford, 1990.


Marie L. Thompson

KEY TERMS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cerci

—A pair of "feelers" at the tip of the abdomen.

Diapause

—A period of delayed development.

Ovipositor

—Egg-laying organ on the tip of a female insect's abdomen.

Palps

—Tiny appendages near the mouth sensitive to touch and chemical detection or taste.

Pheromone

—Hormonal chemical excretion used to attract a mate.

Stridulation

—Chirping, clicking or other audible sounds made by certain insects by rubbing body parts together.

Grasshopper

views updated May 23 2018

GRASSHOPPER

Among the insects mentioned in the Bible as permitted for food are those "that go upon all fours, which have jointed legs above their feet, wherewith to leap upon the earth" (see *Animals of the Bible). These are "the arbeh ("*locust") after its kinds, and the solam (av, jps, "bald locust") after its kinds, and the ḥargol (av, "beetle"; jps, "cricket") after its kinds, and the ḥagav (av, jps, "grasshopper") after its kinds" (Lev. 11:21–22; and see *Dietary Laws). The last three, each followed by the expression "after its kinds," refer to numerous species of grasshopper, there being, according to an amora, as many as 800 (Ḥul. 63b). Although in the Bible ḥagav applies to the grasshopper and not to the locust, it may have the latter meaning in the verse, "if I command the ḥagav to devour the land" (ii Chron. 7:13), as it has in the Mishnah, which speaks of it as being at times a countrywide plague. In Israel there are many species of grasshopper, some small, others up to 2 in. (5 cms.) and more in size. The small grasshopper hiding in the high grass symbolizes the puniness of man when viewed from above (Num. 13:33; Isa. 40:22). All species of the grasshopper in Israel develop (like the locust) by metamorphosis, that is, the larva (zaḥal) has no wings but the adult has wings covering most of its body, an essential characteristic of the permitted grasshopper (Ḥul. 65b). In mishnaic and talmudic times the grasshopper was widely used as food, being also preserved in salt (Av. Zar. 2:7; et al.). There are Yemenite Jews who, on the basis of tradition as to their kashrut, still eat locusts and species of grasshopper.

It is difficult to identify "the solam after its kinds." The word means "destroying, eating," and refers to the grass-eating grasshopper, said to have the characteristic of being gabbaḥat, that is, apparently, having an arched back and slender feelers; many such species are found in Israel. Some identify it with the long-headed grasshopper of the genus Acridium (but see Av. Zar. 37a), i.e., with a species known as ayyal kamẓa which is kasher according to evidence from Second Temple times (Eduy. 8:4). With regard to the next permitted group "the ḥargol after its kinds," the sages stated that the outstanding characteristic of the ḥargol is "that it has a tail." This applies to the long-horned grasshopper of the family Tettigoniidae, whose female has a long protuberance which is a tube for the laying of eggs. Most of these species do no damage to agriculture, since they feed on insects and not on grass. Among them are also species whose imago is wingless, such as the Saga species, the largest grasshopper in Israel, and prohibited as food (see Ḥul. 65b).

bibliography:

Palmoni, in: EM, 1 (1950), 520 6, s.v.Arbeh; J. Feliks, Animal World of the Bible (1962), 116–8. add bibliography: Feliks, Ha-Ẓome'aḥ, 203, 209, 225, 234, 235.

[Jehuda Feliks]

Grasshoppers

views updated May 11 2018

GRASSHOPPERS

GRASSHOPPERS regularly destroyed crops from the start of American agriculture to the early 1950s. These insects fall roughly into migratory and nonmigratory groups. Although migratory grasshoppers (locusts) generally did the most damage, every species caused problems in some part of America. Locusts usually attacked sparsely settled regions, while nonmigratory species typically struck more settled regions. Especially serious attacks occurred in New England in 1743, 1749, 1754, and 1756 and recurred into the nineteenth century, especially in Vermont and Maine. California missions suffered heavily several times in the 1820s, as did farms in Missouri and Minnesota. Grasshoppers appeared in the Great Basin and on the Great Plains in 1855 and at odd intervals thereafter. The great grasshopper plagues of the Plains occurred in 1874–1876. The need for research to prevent attacks factored significantly into the 1863 creation of the Division of Entomology (renamed the Bureau of Entomology in 1904) in the U.S. Department of Agriculture.

The hopperdozer, a device for catching and killing insects, made its first recorded appearance in 1878, but it may have been used as early as 1858. It consisted of a shallow pan on skids with a large screen behind the pan, which farmers pulled across fields. Grasshoppers jumped up, hit the screen, and fell into a pan filled with kerosene or poison. Farmers used hopperdozers well into the twentieth century. Control by bran and molasses mixed with arsenic remained the chief means of effective control until the discovery of the hydrocarbon insecticides, such as chlordane, in the mid-1940s.

In the twentieth century the worst grasshopper attacks occurred in 1931, 1934, 1936, and 1939. The worst of these was the 1936 invasion, which destroyed crops and forage on a grand scale throughout the Midwest and South and especially on the Great Plains. The menace of grasshoppers declined during World War II, and thereafter the use of new insecticides has kept grasshoppers in check.

BIBLIOGRAPHY

Schlebecker, J. T. "Grasshoppers in American Agricultural History." Agricultural History 27 (1953): 85–93.

Sorensen, W. Conner. Brethren of the Net: American Entomology, 1840–1880. Tuscaloosa: University of Alabama Press, 1995.

John T.Schlebecker/c. w.

See alsoAgriculture, Department of ; Insecticides and Herbicides .

grasshoppers

views updated Jun 27 2018

Grasshopper

views updated May 18 2018

Grasshopper

GRASSHOPPER. Lightweight, sturdy, brass three-pounder guns were developed in Britain in the early 1770s and were valued for their high mobility. Officially known as the "Light Infantry Three-Pounder," mounted on a carriage developed by William Congreve, and elevated by a iron screw rather than a wooden quoin, the gun could be drawn by a single horse (known as a "galloper") or disassembled and carried on packhorses, or even by the gunners themselves. It was frequently the only artillery piece that could accompany a unit that had to travel light. Its mobility, along with the manner in which this relatively small field piece recoiled when fired, earned it the nickname "grasshopper."

BIBLIOGRAPHY

Caruana, Adrian B. Grasshoppers and Butterflies: The Light 3 Pounders of Pattison and Townshend. Bloomfield, Ont.: Museum Restoration Service, 1999.

                         revised by Harold E. Selesky

grasshopper

views updated Jun 08 2018

grasshopper the grasshopper, with its chirping sound, is sometimes taken as a type of something frivolous and trivial.

In biblical translations, grasshopper is sometimes used for locust, as in Ecclesiastes 12:1, ‘the grasshopper shall be a burden, and desire shall fail.’

A grasshopper was also the personal emblem of the 16th-century financier Thomas Gresham (see Gresham's law); his house in Lombard Street was known as ‘the Sign of the Grasshopper’, and the badge was later used by Martin's Bank, which originated in Gresham's trading there.

grasshopper

views updated May 21 2018

grasshopper Plant-eating insect. Its enlarged hind legs make it a powerful jumper. The forewings are leathery and the hind wings are membranous and fan-shaped; when the insect is at rest, the wings are folded over its back. Length: 8–11cm (0.3–4.3in). Order Orthoptera; families Acrididae and Tettingoniidae. See also cricket; locust

grasshopper

views updated May 23 2018

grass·hop·per / ˈgrasˌhäpər/ • n. a plant-eating insect (family Acrididae, order Orthoptera) with long hind legs that are used for jumping and for producing a chirping sound.

More From encyclopedia.com