Locust

(Locusta migratoria), are grasshoppers in a migratory phase of their life. ing Australian plague locusts on the move Locusts (derived from the Latin locusta, locust or lobster ) are various species of short-horned grasshoppers in the family Acrididae that have a swarming phase. These insects are usually solitary, but under certain circumstances they become more abundant and change their behaviour and habits, becoming gregarious. No taxonomic distinction is made between locust and grasshopper species; the basis for the definition is whether a species forms swarms under intermittently suitable conditions. Swarming has evolved independently in multiple lineages, comprising at least 18 genera in 5 different subfamilies. Normally, these grasshoppers are innocuous, their numbers are low, and they do not pose a major economic threat to agriculture. However, under suitable conditions of drought followed by rapid vegetation growth, serotonin in their brains triggers dramatic changes: they start to breed abundantly, becoming gregarious and nomadic (loosely described as migratory) when their populations become dense enough. They form bands of wingless nymphs that later become swarms of winged adults. Both the bands and the swarms move around, rapidly strip fields, and damage crops.…

(Locusta migratoria), are grasshoppers in a migratory phase of their life. ing Australian plague locusts on the move Locusts (derived from the Latin locusta, locust or lobster ) are various species of short-horned grasshoppers in the family Acrididae that have a swarming phase. These insects are usually solitary, but under certain circumstances they become more abundant and change their behaviour and habits, becoming gregarious. No taxonomic distinction is made between locust and grasshopper species; the basis for the definition is whether a species forms swarms under intermittently suitable conditions. Swarming has evolved independently in multiple lineages, comprising at least 18 genera in 5 different subfamilies. Normally, these grasshoppers are innocuous, their numbers are low, and they do not pose a major economic threat to agriculture. However, under suitable conditions of drought followed by rapid vegetation growth, serotonin in their brains triggers dramatic changes: they start to breed abundantly, becoming gregarious and nomadic (loosely described as migratory) when their populations become dense enough. They form bands of wingless nymphs that later become swarms of winged adults. Both the bands and the swarms move around, rapidly strip fields, and damage crops. The adults are powerful fliers; they can travel great distances, consuming most of the green vegetation wherever the swarm settles. Locusts have formed plagues since prehistory. The ancient Egyptians carved them on their tombs and the insects are mentioned in the Iliad, the Mahabharata, the Bible and Quran. Swarms have devastated crops and have caused famines and human migrations. More recently, changes in agricultural practices and better surveillance of locust breeding grounds have allowed control measures at an early stage. Traditional locust control uses insecticides from the ground or air, but newer biological control methods are proving effective. Swarming behaviour decreased in the 20th century, but despite modern surveillance and control methods, swarms can still form; when suitable weather conditions occur and vigilance lapses, plagues can occur. Locusts are large insects and convenient for research and classroom study of zoology. They are edible by humans. They have been eaten throughout history and are considered a delicacy in many countries.

Distribution and diversity

Several species of grasshoppers swarm as locusts in different parts of the world, on all continents except Antarctica: For example, the Australian plague locust (Chortoicetes terminifera) swarms across Australia. The desert locust (Schistocerca gregaria) is probably the best known species owing to its wide distribution (North Africa, Middle East, and Indian subcontinent) and its ability to migrate over long distances. A major infestation covered much of western Africa from 2003 to 2005, after unusually heavy rain set up favourable ecological conditions for swarming. The first outbreaks occurred in Mauritania, Mali, Niger, and Sudan in 2003. The rain allowed swarms to develop and move north to Morocco and Algeria, threatening croplands. Swarms crossed Africa, appearing in Egypt, Jordan and Israel, the first time in those countries for 50 years. The cost of handling the infestation was put at US$122 million, and the damage to crops at up to $2.5 billion. The migratory locust (Locusta migratoria), sometimes classified into up to 10 subspecies, swarms in Africa, Asia, Australia, and New Zealand, but has become rare in Europe. In 2013¹, the Madagascan form of the migratory locust formed many swarms of over a billion insects, reaching "plague" status and covering about half the country by March 2013. Species such as the Senegalese grasshopper (Oedaleus senegalensis) and the African rice grasshopper (Hieroglyphus daganensis), both from the Sahel, often display locust-like behaviour and change morphologically on crowding. In North America, the Rocky Mountain locust was formerly one of the most significant insect pests, but it became extinct in 1902. In the 1930s, during the Dust Bowl, a second species of North American locust, the High Plains locust (Dissosteira longipennis), reached plague proportions in the American Midwest. Today, the High Plains locust is a rare species, leaving North America with no regularly swarming locusts.

Interaction with humans and animals

Ancient times

, Ancient Egypt, circa 1422–1411 BC Study of literature shows how pervasive plagues of locusts were over the course of history. The insects arrived unexpectedly, often after a change of wind direction or weather, and the consequences were devastating. The Ancient Egyptians carved locusts on tombs in the period 2470 to 2220 BC. A devastating plague in Egypt is mentioned in the Book of Exodus in the Bible. Locust plague is mentioned in the Indian Mahabharata. The Iliad mentions locusts taking to the wing to escape fire. Plagues of locusts are mentioned in the Quran. In the ninth century BC, the Chinese authorities appointed anti-locust officers. In the New Testament, John the Baptist was said to survive in the wilderness on locusts and wild honey; and human-headed locusts appear in the Book of Revelation. Aristotle studied locusts and their breeding habits and Livy recorded a devastating plague in Capua in 203 BC. He mentioned human epidemics following locust plagues which he associated with the stench from the putrifying corpses; the linking of human disease outbreaks to locust plagues was widespread. A pestilence in the northwestern provinces of China in 311 AD that killed 98% of the population locally was blamed on locusts, and may have been caused by an increase in numbers of rats (and their fleas) that devoured the locust carcasses.

Usage and nutrition

Locusts are considered as meat. They can be cooked in many ways, but are often fried, smoked, or dried. They yield about five times more edible protein per unit of fodder than cattle, and produce lower levels of greenhouse gases in the process. The feed conversion rate of orthopterans is 1.7 kg/kg, while for beef it is typically about 10 kg/kg. The protein content in fresh weight is between 13 and 28 g / 100 g for adult locust, 14–18 g / 100 g for larvae, as compared to 19–26 g / 100 g for beef. The calculated protein efficiency ratio is low, with 1.69 for locust protein compared to 2.5 for standard casein. A serving of 100 g of desert locust provides 11.5 g of fat, 53.5% of which is unsaturated, and 286 mg of cholesterol. Among the fatty acids, palmitoleic, oleic, and linolenic acids were found to be the most abundant. Varying amounts of potassium, sodium, phosphorus, calcium, magnesium, iron, and zinc were present.

Notes

References

External links

Visual neuron of the locust, Ri Channel video, October 2011 FAO Locust Watch FAO EMPRES FAO eLocust3e suite eLocust3M android app Desert Locust Meteorological Monitoring at Sahel Resources Locust Video USAID Supplemental Environmental Assessment of the Eritrean Locust Control Program USAID Supplemental Environmental Assessment: Pakistan Locust Control Programs, August 1993 When The Skies Turned To Black, The Locust Plague of 1875

Text derived from https://en.wikipedia.org/w/index.php?oldid=1372763238 under CC BY-SA 4.0; modifications have been made.