View source for Desert locust

{{Short description|Species of grasshopper}}
{{Multiple issues|
{{External links|date=October 2024}}
{{excessive citations|date=October 2025}}
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{{Speciesbox
|name = Desert locust
|image = SGR laying.jpg
|image_caption = A migratory phase adult laying eggs
|genus = Schistocerca
|species = gregaria
|authority = [[Peter Forsskål|Forsskål]], 1775
|synonyms = 
* ''Acridium peregrina'' {{small|Olivier, 1804}}
* ''Gryllus rufescens'' {{small|Thunberg, 1815}}
}}
[[File:Schistocerca Distribution.png|thumb|Desert locust main initial outbreak areas (modified from Lecoq, 2004 and Sword et al. 2010). In red, outbreak areas; light grey, recession area; light and dark grey together represent the invasion area (modified from Lecoq, 2004 and Sword et al. 2010).]]
The '''desert locust''' ('''''Schistocerca gregaria'''''<ref name=CABI>{{cite book |last1=Lecoq |first1=M |year=2022 |chapter=''Schistocerca gregaria'' (Desert locust) |title=Crop Protection Compendium |location=Wallingford, UK |publisher=CAB International |doi=10.1079/cabicompendium.49833}}</ref><ref name=Orthoptera>{{Cite web|url=http://orthoptera.speciesfile.org/Common/basic/Taxa.aspx?TaxonNameID=1112359|title=species ''Schistocerca gregaria'' (Forskål, 1775): Orthoptera Species File|website=orthoptera.speciesfile.org|access-date=2020-02-16}}</ref><ref>{{Cite web|url=https://www.uniprot.org/taxonomy/7010|title=''Schistocerca gregaria'' (Desert locust) (''Gryllus gregarius'')|website=www.uniprot.org|access-date=2020-02-16}}</ref><ref>{{Cite book |last1=Forskål |first1=Peter |url=https://www.biodiversitylibrary.org/item/18564#page/8/mode/1up |title=Descriptiones Animalium Avium, Amphibiorum, Piscium, Insectorum, Vermium; quae in Itinere Orientali observati Petrus Forskål, Prof. Haun., post morten auctoris. |date=1775 |publisher=Edidit Carsten Niebuhr, Hauniae (Copenhague). 164 pp.}}</ref>) is a species of [[locust]] in the grasshopper family, [[Acrididae]]. A periodically [[Swarm behavior|swarming]], short-horned [[Schistocerca|bird grasshopper]], it is found primarily in the deserts and dry areas of northern and eastern Africa, Arabia, and southwest Asia. During population surge years, its range may extend north into parts of Southern Europe, Eastern Africa, and Northern India. The desert locust shows periodic changes in its body form and can change in response to environmental conditions over several generations. It begins life as a solitary, shorter-winged, highly fecund (producing enormous amounts of offspring), non-migratory form, to a gregarious, long-winged, and migratory phase in which it may travel long distances into new areas. Due to this traveling, it may join groups, thus, forming locust plagues. This involves invading new areas where it may consume all vegetation including valuable crops. Although at other times, it may live unnoticed in small numbers in various areas.

During plague years, when the desert locust does group with others, it can cause widespread damage to crops as it is highly mobile and feeds on large quantities of any kind of green vegetation. A typical swarm can be made up of {{convert|150|e6/km2||abbr=off|adj=pre|locusts }} and fly in the direction of the prevailing wind,<ref>{{cite journal|jstor=4238|title=The Direction of Desert Locust Migration|last1=Draper|first1=J.|journal=Journal of Animal Ecology|year=1980|volume=49|issue=3|pages=959–974|doi=10.2307/4238|bibcode=1980JAnEc..49..959D }}</ref> up to {{cvt|150|km}} in one day. Even a very small, {{convert|1|km2|adj=on}} locust swarm can eat the same amount of food in a day as about 35,000 people.<ref name="fao.org">{{Cite web|url=http://www.fao.org/africa/news/detail-news/en/c/1260476/|title=FAO and partners stress urgent need on Desert Locust Response|website=www.fao.org|access-date=2020-02-16}}</ref>

As an international [[Food and Agriculture Organization#Transboundary pests and diseases|transboundary pest]] that threatens [[agriculture|agricultural]] production and livelihoods in many countries in Africa, the Near East, and southwest Asia, its population has been routinely monitored through a collaborative effort between countries and the [[United Nations]] [[Food and Agriculture Organization]] (FAO) Desert Locust Information Service (DLIS), which provides global and national assessments, forecasts, and early warning to affected countries and the international community. The desert locust's migratory nature and capacity for rapid population growth present major challenges for control, particularly in remote semiarid areas, which characterize much of its range.<ref>{{Cite web|url=http://www.fao.org/ag/locusts/en/publicat/docs/tech/1290/index.html|title=No. 27: Economic and policy issues in Desert Locust management (S. Joffe, 1998)|website=www.fao.org|access-date=2020-02-16}}</ref>

Locusts differ from other grasshoppers in their ability to change from a solitary living form into gregarious, highly mobile, adult swarms and hopper bands, as their numbers and densities increase. They exist in different states known as recessions (with low and intermediate numbers), rising to local outbreaks and regional upsurges with increasingly high densities, to plagues consisting of numerous swarms. They have two to five generations per year. The desert locust risk increases with a one-to-two-year continuum of favourable weather (greater frequency of rains) and habitats that support population increases leading to upsurges and plagues.<ref name=DLCO-EA>{{Cite web |url=http://dlco-ea.org/final/index.php/component/content/article/82-blog/informations/89-desert-locust-on-acacia |title=Desert Locust |website=dlco-ea.org |language=en-gb |access-date=2020-02-16 |archive-date=2020-02-16 |archive-url=https://web.archive.org/web/20200216094340/http://dlco-ea.org/final/index.php/component/content/article/82-blog/informations/89-desert-locust-on-acacia |url-status=dead}}</ref>

The desert locust is potentially the most dangerous of the locust pests because of the ability of [[swarm]]s to fly rapidly across great distances. The [[2003–2005 Africa locust infestation|major desert locust upsurge in 2004–05]] caused significant [[agriculture|crop]] losses in West Africa and diminished [[food security]] in the region. The 2019–2021 upsurge caused similar losses in northeast Africa, the Near East, and southwest Asia.

== Taxonomy ==
The desert locust is a species of orthopteran in the family Acrididae, subfamily Cyrtacanthacridinae.<ref name=Orthoptera/> There are two subspecies, one called ''Schistocerca gregaria gregaria'', the better known and of huge economic importance, located north of the equator, and the other, ''Schistocerca gregaria flaviventris'',<ref>{{Cite journal |last1=Chapuis |first1=M.P. |last2=Bazelet |first2=Corinna S. |last3=Blondin |first3=L. |last4=Foucart |first4=A. |last5=Vitalis |first5=R. |last6=Samways |first6=M.J. |date=2016 |title=Subspecific taxonomy of the desert locust, Schistocerca gregaria (Orthoptera: Acrididae), based on molecular and morphological characters |url=https://resjournals.onlinelibrary.wiley.com/doi/10.1111/syen.12171 |journal=Systematic Entomology |language=en |volume=41 |issue=3 |pages=516–530 |doi=10.1111/syen.12171 |bibcode=2016SysEn..41..516C |issn=0307-6970|url-access=subscription }}</ref><ref>{{cite journal |last1=Chapuis |first1=M.P. |last2=Raynal |first2=L. |last3=Plantamp |first3=C. |last4=Meynard |first4=C.N. |last5=Blondin |first5=L. |last6=Marin |first6=J.M. |last7=Estoup |first7=A. |year=2020 |title=A young age of subspecific divergence in the desert locust inferred by ABC random forest |journal=Molecular Ecology |volume=29 |issue=23 |pages=4542–4558 |doi=10.1111/mec.15663|pmid=33000872 |bibcode=2020MolEc..29.4542C }}</ref> which has a smaller range in south-west Africa and is of less economic importance, although outbreaks have been observed in the past.

== Description ==
{{rewrite section|it should have complete sentences|date=October 2024}}
[[File:Desert.locust.arp.jpg|thumb|A gregarious phase adult|alt=|left]]The genus ''[[Schistocerca]]'' consists of more than 30 species, distributed in Africa, Asia, and North and South America. Many species are difficult to identify due to the presence of variable morphs. [[Schistocerca]] is the only genus within the [[Cyrtacanthacridinae]] that occurs in both the New and Old World. Most species have the [[Glossary of botanical terms|fastigium deflexed]] and lack lateral [[carinae]] on the [[pronotum]]. The hind [[tibia]] have smooth margins with numerous spines, however, there are no apical spine on the outer margin. Males in the genus have broad [[Glossary of botanical terms|anal cerci]] and a split [[Glossary of botanical terms|subgenital plate]]. The genus is thought to have originated in Africa and then [[Speciation|speciated]] in the New World after a dispersal event that took place 6 to 7 million years ago.<ref>{{Cite journal|last=Scudder|first=Samuel H.|date=1899|title=The Orthopteran Genus ''Schistocerca''|journal=Proceedings of the American Academy of Arts and Sciences|volume=34|issue=17|pages=441–476|doi=10.2307/20020916|jstor=20020916|issn=0199-9818}}</ref><ref>{{Cite journal|last1=Lovejoy|first1=N.R|last2=Mullen|first2=S.P|last3=Sword|first3=G.A|last4=Chapman|first4=R.F|last5=Harrison|first5=R.G|date=2006-04-07|title=Ancient trans-Atlantic flight explains locust biogeography: molecular phylogenetics of ''Schistocerca''|journal=Proceedings of the Royal Society B: Biological Sciences|language=en|volume=273|issue=1588|pages=767–774|doi=10.1098/rspb.2005.3381|issn=0962-8452|pmc=1560218|pmid=16618668}}</ref><ref>{{cite journal|doi=10.1093/isd/ixy008|title=Evolution, Diversification, and Biogeography of Grasshoppers (Orthoptera: Acrididae)|year=2018|last1=Song|first1=Hojun|last2=Mariño-Pérez|first2=Ricardo|last3=Woller|first3=Derek A.|last4=Cigliano|first4=Maria Marta|journal=Insect Systematics and Diversity|volume=2|issue=4|article-number=3 |doi-access=free|hdl=11336/90640|hdl-access=free}}</ref>

The morphology and colour of [[Schistocerca]] differ depending on whether individuals are solitary or [[gregarious]].

'''Morphology''' - Adults: Solitary Females are 6–9&nbsp;cm long; Solitary males are 4.5–6&nbsp;cm; gregarious female 5–6&nbsp;cm long; gregarious males 4.5–5&nbsp;cm. The [[Glossary of botanical terms|prosternal tubercle]] is straight, blunt and slightly sloping backwards. The Male [[Glossary of botanical terms|subgenitial plate]] is [[Glossary of botanical terms|biloped]], [[Glossary of botanical terms|ceri]], flat and blunt. [[Glossary of botanical terms|Elytra]] are marked with large irregular spots, and the [[pronotum]] is not crested, and is narrower and saddle-shaped in the gregarious phase. The eyes are [[Wiktionary:striation|striated]], and the number of striae increases after each moult and are only clearly visible in solitary individuals.

'''Coloration''' - Nymph: Solitary nymphs are greenish or pale beige and may go through six [[instar]]s. Gregarious nymphs are typically yellow, with a black head and [[Glossary of botanical terms|pronotum]], black lateral stripes on the abdomen and pass through five instars. During the first instar, gregarious nymphs are almost entirely black. Adults: Immature solitary adults are sandy, pale grey or beige in colour; this colouration evolves to pale yellow in mature male adults and to pale beige with brown patterns in mature females. Immature gregarious adults are pink/reddish in colour, changing to bright yellow in mature males; in mature females the yellow is less bright, mainly on the upper parts of the body, with the lower parts being more of a pale beige. The hindwings are transparent or light yellow.<ref>{{Cite journal|last=Roonwal|first=M. L.|date=1945|title=Two Colour-Types in Solitaria-Phase Adults and Hoppers of the Desert Locust|journal=Nature|language=en|volume=155|issue=3948|pages=792|doi=10.1038/155792a0|bibcode=1945Natur.155..792R|s2cid=4033029|issn=0028-0836|doi-access=free}}</ref>

==Lifecycle==
The lifecycle of the desert locust consists of three stages, the egg, the [[nymph (biology)|nymph]] known as a hopper, and the winged adult. Copulation takes place when a mature male hops onto the back of a mature female and grips her body with his legs. Sperm is transferred from the tip of his abdomen to the tip of hers, where it is stored. The process takes several hours and one insemination is sufficient for a number of batches of eggs.<ref name="Handbook">{{cite web |url=http://www.nzdl.org/gsdlmod?e=d-00000-00---off-0hdl--00-0----0-10-0---0---0direct-10---4-------0-1l--11-en-50---20-about---00-0-1-00-0-0-11-1-0utfZz-8-10-0-0-11-10-0utfZz-8-00&a=d&c=hdl&cl=CL1.10&d=HASHd1edbf77fbe3fa2e5e3da5.4.2 |title=Desert locust: Lifecycle |work=Locust Handbook |publisher=Humanity Development Library |access-date=2015-04-11}}</ref>

The female locust then seeks suitable soft soil in which to lay her eggs. It needs to be the right temperature and degree of dampness and be in close proximity to other egg-laying females. She probes the soil with her abdomen and digs a hole into which an egg pod containing up to 100 eggs is deposited. The egg pod is {{convert|3|to|4|cm|frac=8|abbr=on}} long and the lower end is about {{convert|10|cm|0|abbr=on}} below the surface of the ground. The eggs are surrounded by foam and this hardens into a membrane and plugs the hole above the egg pod. The eggs absorb moisture from the surrounding soil. The incubation period before the eggs hatch may be two weeks, or much longer, depending on the temperature.<ref name="Handbook" />

[[File:S. gregaria dense hopper band.jpg|thumb|left|Dense hopper band in [[Sudan]]]]
The newly hatched nymph soon begins to feed, and if it is a gregarious individual, is attracted to other hoppers and they group together. As it grows, it needs to [[moulting|moult]] (shed its [[exoskeleton]]). Its hard cuticle splits and its body expands, while the new exoskeleton is still soft. The stages between moulting are called [[instar]]s and the desert locust nymph undergoes five moults before becoming a winged adult. Immature and mature individuals in the gregarious phase form bands that feed, bask, and move as cohesive units, while solitary-phase individuals do not seek conspecifics.<ref name="Handbook" /><ref name="Simpson1999" />
[[File:Schisto16.jpg|thumb|Seasonal breeding areas and swarm movements of desert locust during the invasion periods (modified from Pedgley, 1981). Red: summer breeding area with hopper bands present from July to September and direction of swarms (arrows) from August to October. Blue: winter breeding area with hopper bands present from October to February and direction of swarms (arrows) from December to March. Green: spring breeding area with hopper bands present from March to May and direction of swarms (arrows) from April to July. In light grey, the recession area; the light and dark grey together represent the invasion area (Modified from Pedgley, 1981).]]
After the imaginal moult, the young adult is initially soft with drooping wings, but within a few days, the cuticle hardens and [[haemolymph]] is pumped into the wings, stiffening them.

Maturation can occur in 2–4 weeks when the food supply and weather conditions are suitable but may take as long as 6 months when they are less ideal. Males start maturing first and give off an odour that stimulates maturation in the females. On maturing, the insects turn yellow and the abdomens of the females start swelling with developing eggs.<ref name="Handbook" />

==Ecology and swarming==
[[File:DesertLocust.jpeg|thumb|left|Solitary (top) and gregarious (bottom) desert locust nymphs]][[File:A swarm of locusts (cleaned) - Emil Schmidt.jpg|thumb|{{em|Swarm of Locusts}}, 1882–1884 [[chromolithography]] by Emil Schmidt (Brehm, A.E., Bd. 9: 551)]]
[[File:Schisto09.jpg|thumb|Historic image of a high-density desert locust swarm, Morocco, ca. 1954 during the 1949-62 major invasion. Note the very high concentration of locusts masking the landscape in the background. The front of the swarm looks like the front of a sand wind. (photo Hans Brédo, in Liselotte Brédo-Bartelous, 1997)]]

Desert locusts have a solitary phase and a gregarious phase, a type of [[polyphenism]]. Solitary locusts nymphs and adults can behave gregariously within a few hours of being placed in a crowded situation, while gregarious locusts need one or more generations to become solitary when reared in isolation.<ref name="Simpson1999">{{cite journal|last1=Simpson|first1=S.J.|last2=McCaffery|first2=A.R.|last3=Hagele|first3=B.F.|year=1999|title=A behavioural analysis of phase change in the desert locust|journal=Biological Reviews|volume=74|issue=4|pages=461–480|doi=10.1111/j.1469-185x.1999.tb00038.x|s2cid=86261709}}</ref> Differences in [[Morphology (biology)|morphology]] and behaviour are seen between the two phases. In the solitary phase, the hoppers do not group together into bands but move about independently. Their colouring in the later instars tends to be greenish or brownish to match the colour of their surrounding vegetation. The adults fly at night and are also coloured so as to blend into their surroundings, the immature adults being grey or beige and the mature adults being a pale yellowish colour. In the gregarious phase, the hoppers bunch together and in the later instars develop a bold colouring with black markings on a yellow background. The immatures are pink and the mature adults are bright yellow and fly during the day in dense swarms.<ref name=Handbook/>[[File:Schistocerca gregaria 01.jpg|thumb|right|Desert locusts preparatory to mating, London Zoo]]

The change from an innocuous solitary insect to a voracious gregarious one normally follows a period of drought, when rain falls and vegetation flushes occur in major desert locust breeding locations. The population builds up rapidly and the competition for food increases.<ref name=Showler>{{cite web |url=http://ipmworld.umn.edu/chapters/showler.htm |title=The Desert Locust in Africa and Western Asia: Complexities of War, Politics, Perilous Terrain, and Development |author=Showler, Allan T. |date=2013-03-04 |work=Radcliffe's IPM World Textbook |publisher=University of Minnesota |access-date=2015-04-11 |url-status=dead |archive-url=https://web.archive.org/web/20150408034918/http://ipmworld.umn.edu/chapters/showler.htm |archive-date=2015-04-08 }}</ref> As hoppers get more crowded, the close physical contact causes the insects' hind legs to bump against one another. This [[Stimulus (physiology)|stimulus]] triggers a cascade of [[metabolic]] and behavioral changes that causes the insects to transform from the solitary to the gregarious phase. When the hoppers become gregarious, their colouration changes from largely green to yellow and black, and the adults change from brown to pink (immature) or yellow (mature). Their bodies become shorter, and they give off a [[pheromone]] that causes them to be attracted to each other, enhancing hopper band and subsequently [[swarm]] formation. The nymphal pheromone is different from the adult one. When exposed to the adult pheromone, hoppers become confused and disoriented, because they can apparently no longer "smell" each other, though the visual and tactile stimuli remain. After a few days, the hopper bands disintegrate and those that escape predation become solitary again.

During quiet periods, called recessions, desert locusts are confined to a {{convert|16|e6km2|abbr=off|adj=on}} belt that extends from [[Mauritania]] through the [[Sahara Desert]] in [[northern Africa]], across the [[Arabian Peninsula]], and into northwest [[India]]. Under optimal ecological and climatic conditions, several successive generations can occur, causing swarms to form and invade countries on all sides of the recession area, as far north as [[Spain]] and [[Russia]], as far south as [[Nigeria]] and [[Kenya]], and as far east as India and southwest Asia. As many as 60 countries can be affected within an area of {{convert|32|e6km2|abbr=off}}, or about 20% of the Earth's land surface.<ref name=Sword-2010>{{Cite journal |last1=Sword |first1=Gregory A. |last2=Lecoq |first2=Michel |last3=Simpson |first3=Stephen J. |date=2010-08-01 |title=Phase polyphenism and preventative locust management |url=https://linkinghub.elsevier.com/retrieve/pii/S0022191010001460 |journal=Journal of Insect Physiology |series=Locust Research in the Age of Model Organisms In honor of M.P. Pener's 80th Birthday |volume=56 |issue=8 |pages=949–957 |doi=10.1016/j.jinsphys.2010.05.005 |pmid=20493192 |bibcode=2010JInsP..56..949S |issn=0022-1910|url-access=subscription }}</ref>

Locust swarms fly with the wind at roughly the speed of the wind. They can cover from {{cvt|100|to|200|km|mi|abbr=on}} in a day, and  fly up to about {{convert|2,000|m}} above sea level (the temperature becomes too cold at higher altitudes). Therefore, swarms cannot cross tall mountain ranges such as the [[Atlas Mountains|Atlas]], the [[Hindu Kush]], or the [[Himalayas]]. They do not venture into the [[rain forest]]s of Africa nor into central Europe. However, locust adults and swarms regularly cross the [[Red Sea]] between Africa and the Arabian Peninsula, and are even reported to have crossed the [[Atlantic Ocean]] from [[Africa]] to the [[Caribbean]] in 10 days during the 1987–89 plague.<ref name="FAO">{{cite web|url=http://www.fao.org/newsroom/en/focus/2006/1000345/|title=Biological control of locusts|date=31 July 2006|publisher=[[Food and Agriculture Organization]]|access-date=29 March 2013|archive-date=5 November 2019|archive-url=https://web.archive.org/web/20191105153921/http://www.fao.org/newsroom/en/focus/2006/1000345/|url-status=dead}}</ref> A single swarm can cover up to {{convert|1200|km2}} and can contain between {{convert|40 and 80|e6/km2||abbr=off|adj=pre|locusts }} (a total of around 50 to 100 billion locusts per swarm, representing {{convert|100,000 to 200,000|MT}}, considering an average mass of 2 g per locust). The locust can live between 3 and 6 months, and a 10- to 16-fold increase in locust numbers occurs from one generation to the next.

== Impacts of the desert locust ==

=== Economic impact ===
The desert locust is probably the oldest and most dangerous migratory pest in the world. The scale of the invasions and destruction they cause is due to their exceptional gregarious nature, their mobility, the voracity and size of their hopper bands and swarms. Desert locust invasions can be absolutely devastating and have serious repercussions on national and regional food security and on the livelihoods of affected rural communities, particularly the poorest. Added to this damage is the cost of control operations implemented to protect crops, which also help to stop the spread of the invasion, which could otherwise continue for many years and over larger areas. Furthermore, the damage is not limited to crops, but must also include the multiple social and environmental consequences of invasions, which are now better understood and taken into account, even if they are difficult to estimate.<ref>{{Cite web |last=Brader |first=L. |last2=Djibo |first2=H. |last3=Faye |first3=F.G. |last4=Ghaout |first4=S. |last5=Lazar |first5=M. |last6=Luzietoso |first6=P.N. |last7=Ould Babah |first7=M.A. |date=July 2006 |title=Towards a More Effective Response to Desert Locusts and their Impacts on Food Security, Livelihoods and Poverty |url=https://en.wikipedia.org/wiki/Wikipedia:Bare_URLs |archive-url=https://web.archive.org/web/20240114114019/http://www.fao.org/ag/locusts/common/ecg/1913/en/DesertLocustEvalReportE.pdf |archive-date=2024-01-14 |website=[[Food and Agriculture Organization]]}}</ref>

Desert locusts consume an estimated equivalent of their body weight ({{convert|2|g|2|abbr=on}}) each day in green vegetation. They are [[List of feeding behaviours#By food type|polyphagous]] and feed on leaves, shoots, flowers, fruit, seeds, stems, and bark. Nearly all crops and noncrop plants are eaten, including [[pearl millet]], [[maize]], [[sorghum]], [[barley]], [[rice]], pasture grasses, [[sugarcane]], [[cotton]], fruit trees, [[date palm]]s, banana plants, vegetables, and weeds.<ref name="Showler" />

[[File:Locusts feeding.jpg|thumb|Locusts feeding]]
Crop loss from locusts was noted in the [[Bible]] and [[Qur'an]]; these insects have been documented as contributing to the severity of a number of [[Ethiopian famine]]s. Since the early 20th century, desert locust plagues occurred in 1926–1934, 1940–1948, 1949–1963, 1967–1969, 1987–1989, 2003–2005, and 2019–2020.<ref>{{Cite web|url=http://www.fao.org/news/story/en/item/1259082/icode/|title=FAO - News Article: FAO appeals for urgent support to fight worsening Desert Locust upsurge in the Horn of Africa|website=www.fao.org|language=en|access-date=2020-02-16}}</ref> In March–October 1915, a plague of locusts stripped [[History of Palestine#Ottoman period|Ottoman Palestine]] of almost all vegetation.<ref>{{Cite web|url=https://www.loc.gov/exhibits/americancolony/amcolony-locust.html|title=The Locust Plague - The American Colony in Jerusalem {{pipe}} Exhibitions - Library of Congress|first1=Horatio|last1=Spafford|first2=The National|last2=Geographic|date=January 12, 2005|website=www.loc.gov}}</ref> The significant crop loss caused by swarming desert locusts exacerbates problems of food shortage, and is a threat to food security.

=== Environmental impact ===
Desert locust control still relies mainly on chemical pesticides. In the event of an invasion, control operations are of such magnitude that the products used can have serious side effects on human health, the environment, non-target organisms and biodiversity. These side effects are increasingly well known. Correct application of the preventive strategy recommended by the FAO<ref>{{cite web | url=https://www.fao.org/locust-watch/en | title=Home {{pipe}} Locust Watch {{pipe}} Food and Agriculture Organization of the United Nations (FAO) }}</ref> and the use of good treatment practices that are more respectful of people and the environment can limit the negative impacts of these large-scale sprayings.

=== Social impact ===
The external social costs to the local human population during desert locust outbreaks can be enormous, but difficult to estimate. Crop and pasture losses can lead to severe food shortages and a large imbalance in food rations, large price fluctuations in markets, insufficient availability of grazing areas, the sale of animals at very low prices to meet household subsistence needs and to buy feed for remaining animals, early transhumance of herds and high tensions between transhumant herders and local farmers, and significant human migration to urban areas (sometimes fatal for the elderly, the weak and young children). Other economic consequences can occur during harvest, as cereals can be contaminated with insect parts and downgraded to feed grains that are sold at a lower price. In addition, the negative income shock can have a long-term impact on the educational outcomes of children living in rural areas.<ref>{{Cite journal |last1=De Vreyer |first1=P. |last2=Guilbert |first2=N. |last3=Mesple-Somps |first3=S. |date=2015-01-01 |title=Impact of Natural Disasters on Education Outcomes: Evidence from the 1987-89 Locust Plague in Mali |url=https://academic.oup.com/jae/article-lookup/doi/10.1093/jae/eju018 |journal=Journal of African Economies |language=en |volume=24 |issue=1 |pages=57–100 |doi=10.1093/jae/eju018 |issn=0963-8024|url-access=subscription }}</ref>

=== Beneficial impact ===
The potential benefits of locust swarms are seldom acknowledged. However, locusts are not all bad, as the biomass of locust individuals contributes greatly to ecosystem processes in case of an invasion. Locust frass and cadavers are rich in nutrients which are transferred to the soil via decomposition by micro-organisms and fungi, absorbed by plants, increasing net ecosystem productivity and ecosystem nutrient cycling through rapid mineralization rates of nitrogen and carbon.<ref>{{Cite journal |last1=Kietzka |first1=Gabriella J. |last2=Lecoq |first2=Michel |last3=Samways |first3=Michael J. |date=September 2021 |title=Ecological and Human Diet Value of Locusts in a Changing World |journal=Agronomy |language=en |volume=11 |issue=9 |pages=1856 |doi=10.3390/agronomy11091856 |bibcode=2021Agron..11.1856K |doi-access=free |issn=2073-4395}}{{Creative Commons text attribution notice|cc=by4|from this source=yes}}</ref>

==Early warning and preventive control==
Early warning and preventive control is the strategy adopted by locust-affected countries in Africa and Asia to try to stop locust plagues from developing and spreading.<ref>Lecoq, M., 2003. Desert Locust Threat to Agricultural Development and Food Security and FAO/ International Role in its Control. ''Arab Journal of Plant Protection'' 21:188-193. https://agritrop.cirad.fr/518863</ref><ref name=Sword-2010/> In the 1920s-1930s, locust control became a major field for international cooperation. The International Agricultural Institute developed several programmes aimed at exchanging data about the desert locust and international conferences were held in the 1930s: [[Rome]] in 1931, [[Paris]] in 1932, [[London]] in 1934, [[Cairo]] in 1936, and [[Brussels]] in 1938. Colonial empires were heavily involved in these attempts to control locust pests, which affected heavily the Middle East and parts of Africa.<ref>Antonio Buj, « International Experimentations and Control of the Locust Plague – Africa in the First Half of the 20th Century », in Yvon Chatelin, Christophe Bonneuil (eds.), Les sciences hors d'Occident au XXe siècle, Vol. 3 : Nature et environment, Paris, Orstom Editions, 1995, pp. 93-105.</ref> The USSR also used locust control as a way to expand its influence in the Middle East and Central Asia.<ref>{{Cite journal|title=Fighting Locusts Together: Pest Control and the Birth of Soviet Development Aid, 1920-1939|first=Etienne|last=Forestier-Peyrat|date=October 25, 2014|journal=Global Environment|volume=7|issue=2|pages=536–571|doi=10.3197/ge.2014.070211|bibcode=2014GlEnv...7..536F |s2cid=87804243 |url=https://halshs.archives-ouvertes.fr/halshs-01783386/file/Fighting%20Locusts%20Together.pdf}}</ref>

[[FAO]]'s Desert Locust Information Service (DLIS) in Rome monitors the weather, ecological conditions, and the locust situation on a daily basis. DLIS receives results of survey and control operations carried out by national teams in affected countries. The teams use a variety of innovative digital devices, such as eLocust3,<ref>{{cite web | url=http://www.fao.org/ag/locusts/en/activ/2573/eL3suite/index.html | title=Activities {{pipe}} Locust Watch {{pipe}} Food and Agriculture Organization of the United Nations (FAO) }}</ref> to collect, record and transmit standardized data in real-time to their national locust centres for decision-making. This data is automatically integrated into SWARMS, the global monitoring and early warning system operated by DLIS. Within this system, the field data are combined with the latest [[satellite]] imagery to actively monitor rainfall, vegetation and soil moisture conditions in the locust breeding area from West Africa to India. This is supplemented by sub-seasonal and seasonal temperature and rainfall predictions up to six months in advance as well as other weather forecasts and data from [[NOAA]] and [[ECMWF]]. Models are used to estimate egg and hopper development rates and swarm trajectories (NOAA [[HYSPLIT]]) and dispersion (UK Met Office [[NAME (dispersion model)|NAME]]). DLIS uses a custom GIS to analyze the field data, satellite imagery, weather predictions and model results to assess the current situation and forecast the timing, scale, and location of breeding and migration up to six weeks in advance. The situation assessments and forecasts are published in monthly locust bulletins that date back to the 1970s. These are supplemented by warnings and alerts to affected countries and the international community. This information is available on the FAO Locust Watch website. DLIS continuously adopts the latest technologies as innovative tools,<ref>{{cite web | url=http://www.fao.org/ag/locusts/en/activ/2573/index.html | title=Activities {{pipe}} Locust Watch {{pipe}} Food and Agriculture Organization of the United Nations (FAO) }}</ref> including drones, to improve monitoring and early warning. FAO also provides information and training to affected countries and coordinates funding from donor agencies in case of major upsurges and plagues.

The desert locust is a difficult pest to control, and control measures are further compounded by the large and often remote areas ({{convert|16-30|e6km2|abbr=off}}) where locusts can be found. Undeveloped basic [[infrastructure]] in some affected countries, limited resources for locust monitoring and control, and political turmoil within and between affected countries further reduce the capacity of a country to undertake the necessary monitoring and control activities.

At present, the primary method of controlling desert locust infestations is with [[insecticides]] applied in small, concentrated doses by vehicle-mounted and aerial sprayers at [[ultra-low volume]] rates of application. The insecticide is acquired by the insect directly, meaning that control must be precise. Control is undertaken by [[government]] agencies in locust-affected countries or by specialized regional aerial organizations such as the Desert Locust Control Organization for East Africa (DLCO-EA).<ref name=DLCO-EA/>

The desert locust has natural enemies such as predatory wasps and flies, [[parasitoid wasp]]s, predatory beetle larvae, [[bird]]s, and [[reptile]]s. These may be effective at keeping solitary populations in check but are of limited effects against gregarious desert locusts because of the enormous numbers of insects in the swarms and hopper bands.<ref name=Showler/>

Farmers often try mechanical means of killing locusts, such as digging trenches and burying hopper bands, but this is very labour-intensive and is difficult to undertake when large infestations are scattered over a wide area. Farmers also try to scare locust swarms away from their fields by making noise, [[burning tires]], or other methods. This tends to shift the problem to neighbouring farms, and locust swarms can easily return to reinfest previously visited fields.

In Libya, a desert locust invasion is particularly threatening the crops and flora of the oases and their farms.<ref>{{cite web |url=https://www.lemonde.fr/afrique/article/2025/04/11/en-libye-une-invasion-de-criquets-pelerins-menace-les-cultures-du-sud-du-pays_6594244_3212.html |title=En Libye, une invasion de criquets pèlerins menace les cultures du sud du pays|work=Le Monde |date=11 April 2025 |access-date=11 April 2025}}</ref>

==Biopesticides==
[[Biological insecticide|Biopesticides]] include fungi, bacteria, [[neem]] extract, and pheromones. The effectiveness of many biopesticides equals that of conventional chemical pesticides, but two distinct differences exist. Biopesticides in general take longer to kill insects, plant diseases, or weeds, usually between 2 and 10 days.

The two types of biopesticides are biochemical and microbial. Biochemical pesticides are similar to naturally occurring chemicals and are nontoxic, such as insect pheromones used to locate mates, while microbial biopesticides, come from bacteria, fungi, algae, or viruses that either occur naturally or are genetically altered. [[Entomopathogenic fungi]] generally suppress pests by mycosis - causing a disease that is specific to the insect.

[[Biological control]] products have been under development since the late 1990s; [[LUBILOSA#Commercialisation|Green Muscle]] and [[LUBILOSA#Post-LUBILOSA|NOVACRID]] are based on a naturally occurring entomopathogenic fungus, ''[[Metarhizium acridum]]''. Species of ''Metarhizium'' are widespread throughout the world, infecting many groups of insects, but pose low risk to humans, other [[mammal]]s, and birds. The species ''M. acridum'' has specialised in short-horned [[caelifera|grasshopper]]s, to which these locusts belong, so has been chosen as the active ingredient of the product.

The product is available in Australia under the name Green Guard and in Africa, it used to be available as Green Muscle. However, since Green Muscle seems to have disappeared from the market, another product, NOVACRID, was developed for Africa, Central Asia, and the Middle East. These products are applied in the same way as chemical insecticides, but do not kill as quickly. At recommended doses, the fungus can take up to two weeks to kill up to 90% of the locusts. For that reason, it is recommended for use mainly against hoppers, the wingless early stages of locusts. These are mostly found in the desert, far from cropping areas, where the delay in death does not result in damage. The advantage of the product is that it affects only grasshoppers and locusts, which makes it much safer than chemical insecticides. Specifically, it allows the natural enemies of locusts and grasshoppers to continue preying upon them. These include birds, [[parasitoid]] and [[predator]]y [[wasp]]s, parasitoid [[fly|flies]], and certain species of [[beetle]]s. Though natural enemies cannot prevent plagues, they can limit the frequency of outbreaks and contribute to their control. Biopesticides are also safer to use in environmentally sensitive areas such as national parks or near rivers and other water bodies.

Green Muscle was developed under the [[LUBILOSA]] programme, which was initiated in 1989 in response to environmental concerns over the heavy use of chemical insecticides to control locusts and grasshoppers during the 1987-89 plague. The project focused on the use of beneficial disease-causing [[microorganism]]s ([[pathogen]]s) as biological control agents for grasshoppers and locusts. These insects were considered too mobile and too fecund for their numbers to be curbed by classical biological control. Pathogens bear a distinct advantage in that many can be produced in artificial culture in large quantities and be used with ubiquitous spraying equipment. Entomopathogenic fungi were traditionally regarded as needing humid conditions to be effective. However, the LUBILOSA programme devised a method to overcome this by [[pesticide application|spraying]] fungal spores in an oil [[pesticide formulation|formulation]]. Even under desert conditions, Green Muscle can be used to kill locusts and other [[Acrididae|acridid]] pests, such as the [[Senegalese grasshopper]]. During trials in Algeria and Mauritania in 2005 and 2006, various natural enemies, but especially birds, were abundant enough to eliminate treated hopper bands in about a week, because the diseased hoppers became sluggish and easy to catch.

==Desert locust plagues and upsurges==
In the 1900s, there were six major desert locust plagues,<ref>{{cite web | url=http://www.fao.org/ag/locusts/en/archives/2331/index.html | title=Desert Locust plagues }}</ref> one of which lasted almost 13{{spaces}}years.
[[File:Schisto14.png|thumb|Territories recording Desert Locust swarms 1860–2020 (after Waloff, 1966, 1976, and Magor et al. 2008, updated). Notice the sharp decrease in the importance of the invasions from the 1960s (After Waloff, 1966, 1976, and Magor et al. 2008, updated).]]

===1915 Ottoman Syria locust infestation===
{{Further|1915 Ottoman Syria locust infestation}}
From March to October 1915, [[Swarm behaviour|swarms]] of [[locust]]s stripped areas in and around [[Palestine (region)|Palestine]], [[Mount Lebanon]] and [[Syria (region)|Syria]] of almost all [[vegetation]]. This infestation seriously compromised the already-depleted [[Food security|food supply]] of the region and sharpened the misery of all [[Jerusalem]]ites.<ref name="loc">{{cite web|url=http://memory.loc.gov/ammem/collections/americancolony/locusts.html|title=The Locust Plague of 1915 Photograph Album|publisher=Library of Congress|access-date=7 January 2011| archive-url= https://web.archive.org/web/20110107011258/http://memory.loc.gov/ammem/collections/americancolony/locusts.html| archive-date= 7 January 2011 | url-status= live}}</ref>

===1960s to present===
Since the early 1960s, there have been two desert locust plagues (1967-1968<ref>{{cite web | url=http://www.fao.org/ag/locusts/en/archives/2331/196769/index.html | title=Desert Locust plague in 1967–69 }}</ref> and 1986-1989<ref>{{cite web | url=http://www.fao.org/ag/locusts/en/archives/2331/1986plague/index.html | title=Desert Locust plague in 1986–89 }}</ref>) and six desert locust upsurges (1972–1974,<ref>{{cite web | url=http://www.fao.org/ag/locusts/en/archives/1146/1972up/index.html | title=Desert Locust upsurge in 1972-1974 }}</ref> 1992–1994,<ref>{{cite web | url=http://www.fao.org/ag/locusts/en/archives/1146/upsurge/index.html | title=Desert Locust upsurge in 1992-1994 }}</ref> 1994–1996,<ref>{{cite web | url=http://www.fao.org/ag/locusts/en/archives/1146/1994up/index.html | title=Desert Locust upsurge in 1994-1996 }}</ref> 2004–2005,<ref>{{cite web | url=http://www.fao.org/ag/locusts/en/archives/1146/web04/index.html | title=Desert Locust upsurge in 2004–2005 }}</ref> 1996–1998,<ref>{{cite web | url=http://www.fao.org/ag/locusts/en/archives/1146/1164/index.html | title=Desert Locust upsurge in 1996-1998 }}</ref> and 2019-2021<ref>{{cite web | url=http://www.fao.org/ag/locusts/en/info/2094/index.html | title=Desert Locust upsurge (2019–2021) }}</ref>).

===2004–2005 upsurge (West Africa)===
{{Main|2004 locust outbreak}}
From October 2003 to May 2005, West Africa faced the largest and most numerous desert locust infestations in 15 years. The upsurge started as small, independent outbreaks that developed in Mauritania, Mali, Niger, and Sudan in the autumn of 2003. Two days of unusually heavy rains that stretched from Dakar, [[Senegal]], to [[Morocco]] in October allowed breeding conditions to remain favourable for the next 6 months and the desert locusts rapidly increased. Lack of rain and cold temperatures in the winter breeding area of northwest Africa in early 2005 slowed the development of the locusts and allowed the locust control agencies to stop the cycle. During the upsurge, nearly {{convert|130,000|km2|abbr=off}} were treated by ground and aerial operations in 23 countries. The costs of fighting this upsurge have been estimated by the FAO to have exceeded US$400&nbsp;million, and harvest losses were valued at up to US$2.5&nbsp;billion, which had disastrous effects on food security in West Africa. The countries affected by the 2004-2005 upsurge were [[Algeria]], [[Burkina Faso]], the [[Canary Islands]], [[Cape Verde]], [[Chad]], [[Egypt]], [[Ethiopia]], [[the Gambia]], [[Greece]], [[Guinea]], [[Guinea Bissau]], [[Israel]], [[Jordan]], [[Lebanon]], [[Libyan Arab Jamahiriya]], [[Mali]], [[Mauritania]], [[Morocco]], [[Niger]], [[Saudi Arabia]], [[Senegal]], [[Sudan]], [[Syria]], and [[Tunisia]].

===2019–2021 desert locust upsurge===

In May 2018, [[Cyclone Mekunu]] brought unprecedented rainfall to the [[Empty Quarter]] of the Arabian Peninsula that was followed by [[Cyclone Luban]] that brought heavy rains again to the same area in October. This allowed conditions to be favourable for three generations of breeding, which caused an estimated 8,000-fold increase in Desert Locust numbers that went unchecked because the area was so remote it could not be accessed by national locust teams.

In early 2019, waves of swarms migrated from this remote and inaccessible area north to the interior of Saudi Arabia and southern Iran, and southwest to the interior of Yemen. Both areas received good rains, including heavy flooding in southwest Iran (the worst in 50 years), that allowed another two generations of breeding to take place. While control operations were mounted against the northern movement and subsequent breeding, very little could be done in Yemen due to the ongoing conflict. As a result, new swarms formed that crossed the southern Red Sea and the Gulf of Aden and invaded the Horn of Africa, specifically northeast Ethiopia and northern Somalia in June 2019. Again, good rains allowed further breeding during the summer, followed by another generation of widespread breeding during the autumn in eastern Ethiopia and central Somalia, which was exacerbated by the unusually late occurring [[Cyclone Pawan]] in northeast Somalia in early December. The swarms that subsequently formed invaded Kenya in late December 2019 and spread throughout the country where they bred in between the rainy seasons because of unusual rainfall. Kenya had only witnessed swarm invasions twice in the past 75 years (1955 and 2007). Some swarms also invaded Uganda, South Sudan, Tanzania and one small swarm reached northeast D.R. Congo, the first time since 1945.

The situation improved in Kenya and elsewhere by the summer of 2020 due to large-scale aerial control operations, made available by generous assistance from international partners. Nevertheless, food security and livelihoods were impacted throughout the region. Despite the control efforts, good rains continued to fall and breeding occurred again during the summer and autumn in Ethiopia and Somalia that led to another invasion of Kenya in December 2020, which was eventually brought under control by spring 2021. Again, unexpected rains fell in late April and early May, this time further north that allowed substantial breeding to occur in eastern Ethiopia and northern Somalia in May and June 2021. New swarms formed in June and July that moved to northeast Ethiopia for a generation of breeding that could not be addressed due to conflict and insecurity, which prolonged the upsurge in the Horn of Africa. The upsurge was finally brought under control by early 2022 as a result of successful and intensive control operations in northern Somalia and poor rainfall.{{citation needed|date=April 2022}} {{As of|2022|4|1}} there are no locust crises anywhere in the world but swarms are expected in October in the [[Sahel]], [[Yemen]] and on the [[India–Pakistan border]].<ref name="FAO20220401">{{cite web | title=Desert Locust situation update 1 April 2022 | website=[[Food and Agriculture Organization]] of the United Nations | date=2022-04-01 | url=http://www.fao.org/ag/locusts/en/info/info/index.html}}</ref>

In southwest Asia, the upsurge was brought under control much  earlier because of a massive effort undertaken by India and Pakistan along both sides of their common border during the summer of 2020 that followed from earlier control operations during the spring of 2019 and 2020 by Iran and during the summer of 2019 by Pakistan and India.<ref>{{Cite web|title=A newspaper article on the possibilities of the Desert Locust (''Schistocerca gregaria'') swarm entering West Bengal, India|url=https://www.researchgate.net/publication/348699056|access-date=2021-11-23|website=ResearchGate|language=en}}</ref> In June 2020, [[Cyclone Nisarga]] helped spread swarms across the northern states of India where a few reached the Himalayan foothills in Nepal.

In response to the upsurge, the Director-General of FAO declared a Level 3 corporate-wide emergency, the highest level in the UN system, on 17 January 2020 and appealed for immediate international assistance to rapidly upscale monitoring and control activities in the Horn of Africa. One month later, [[Somalia]] declared a state of emergency.<ref>{{Cite news|url=https://www.bbc.com/news/world-africa-51348517|title=Somalia declares emergency over locust swarms|date=2020-02-02|work=BBC News|access-date=2020-02-18|language=en-GB}}</ref> Similarly, Pakistan also declared a state of emergency. The UN continued to warn that the Horn of Africa was facing a dangerous situation.<ref name="fao.org"/>

Fortunately, the international community responded quickly and generously despite other urgent situations such as COVID-19, and the $230 million appeal by FAO was fully funded. This  allowed ground and aerial operations to treat {{convert|2.3|e6ha|abbr=off}} of desert locust in the Horn of Africa and Yemen in 2020 and 2021. Up to 20 aircraft were deployed simultaneously, supported by hundreds of ground teams, and more than 1.4 million locations were surveyed. These collective efforts averted {{convert|4.5|e6MT|abbr=off}} of crop losses, saved {{convert|900|e6L|abbr=off}} of milk production, and secured food for nearly 47 million people. The commercial value of the cereal and milk loss averted is estimated at $1.77 billion.{{citation needed|date=April 2022}}

FAO's Locust Watch contains the latest situation and forecasts as well as a full, detailed description of the recent upsurge.<ref>{{cite web | url=https://www.fao.org/ag/locusts/en/info/2094/index.html | title=Desert Locust upsurge (2019–2021) }}</ref>

== Pheromones ==
The [[swarming]] pheromone [[guaiacol]] is produced in the gut of desert locusts by the breakdown of plant material. This process is undertaken by the gut bacterium [[Pantoea agglomerans|''Pantoea'' (''Enterobacter'') ''agglomerans'']]. Guaiacol is one of the main components of the [[pheromone]]s that cause locust swarming.<ref>{{Cite journal | doi=10.1038/35002669| pmid=10706273| title=Exploitation of gut bacteria in the locust| journal=Nature| volume=403| issue=6772| pages=851| year=2000| last1=Dillon| first1=Rod J.| last2=Vennard| first2=Chris T.| last3=Charnley| first3=A. Keith| s2cid=5207502| doi-access=free}}</ref> Pheromones also accelerate ''S. gregaria'' development.<ref name="Wertheim-et-al-2005">{{cite journal | last1=Wertheim | first1=Bregje | last2=van Baalen | first2=Erik-Jan A. | last3=Dicke | first3=Marcel | last4=Vet | first4=Louise E.M. | title=Pheromone-Mediated Aggregation in Nonsocial Arthropods: An Evolutionary Ecological Perspective | journal=[[Annual Review of Entomology]] | publisher=[[Annual Reviews (publisher)|Annual Reviews]] | volume=50 | issue=1 | date=2005-01-01 | issn=0066-4170 | doi=10.1146/annurev.ento.49.061802.123329 | pages=321–346| pmid=15355243 }}</ref> Mahamat ''et al.'', 1993 find that an undifferentiated mix of several [[Volatile organic compounds|volatiles]] derived from the males of the species (including guaiacol) speed up the maturation process of both immature males and females.<ref name="Wertheim-et-al-2005" />

== In research ==
''S. gregaria'' was one of the organisms examined by McNeill and Hoyle 1967 and found to have thinner [[muscle filament]]s than those before found. This contributed greatly to the development of the [[sliding filament theory]].<ref name="Lindstedt-Nishikawa-2017">{{cite journal | last1=Lindstedt | first1=Stan | last2=Nishikawa | first2=Kiisa | title=Huxleys' Missing Filament: Form and Function of Titin in Vertebrate Striated Muscle | journal=[[Annual Review of Physiology]] | publisher=[[Annual Reviews (publisher)|Annual Reviews]] | volume=79 | issue=1 | date=2017-02-10 | issn=0066-4278 | doi=10.1146/annurev-physiol-022516-034152 | pages=145–166| pmid=27813826 }}</ref>

Westerman<ref name = Westerman1967>Westerman, M. The effect of X-irradiation on male meiosis in Schistocerca gregaria (Forskål). Chromosoma 22, 401–416 (1967). https://doi.org/10.1007/BF00286545</ref> showed that exposure of ''S. gregaria'' males to a dose of [[X-ray]]s during the [[S-phase]] (DNA synthesis phase) of [[spermatogonial]] [[mitosis|mitoses]] and during the early stages of [[meiosis]] ([[leptotene stage|leptotene]]-early zygotene stages) caused a significant increase in [[chiasma (genetics)|chiasmata]] frequency when scored at the later stages (diplotene-diakinesis stages) of meiosis. These results indicated that the formation of chiasmata  is not an isolated event but the end product of an interrelated series of processes initiated at some earlier stage of meiosis.<ref name = Westerman1967/>

== In culture ==
Given the long history of desert locust, it is to be expected that references of the world's most dangerous migratory pest have crept into popular film and literature as well as many of the world's religions.

===Film===
Owing to the destructive habits of locusts, they have been a representation of famine in many Middle Eastern cultures, and are seen in the movies ''[[The Mummy (1999 film)|The Mummy]]'' (1999) and ''[[The Bible (movie)|The Bible]]'' (1966).

===Religious books===
This species has been identified as one of the [[Kosher locust|kosher species of locusts]] mentioned in Leviticus 11:22 by several [[rabbi]]nical authorities among Middle Eastern [[Jewish]] communities.

===Literature===
* 1939 - The Day of the Locust by Nathanael West.
* 1948 - Poka ({{langx|bn|'''পোকা'''}}) ({{translation| The Insect}}) by [[Premendra Mitra]].

== Gallery ==
<gallery>
File:Schistocerca gregaire mature.jpg|Mating of adult desert locusts (photo FAO-DLIS)
File:Schistocerca gregaire immature.jpg|Immature adult of the desert locust (photo Said Ghaout, CNLAA, Maroc)
File:Schistocerca solitaire 01.jpg|Solitary adult of the desert locust (photo Michel Lecoq)
File:Schistocerca solitaire 02.jpg|Solitary adult of the desert locust (photo Michel Lecoq)
File:Schisto05.jpg|Nymphs of the desert locust: green (a) and brown (b) solitarious nymphs (5th instar); gregarious nymphs of 4th (c) and 5th instars (d) (a, Michel Lecoq; b, Antoine Foucart; c and d, Gilles Balança; CIRAD)
File:Schisto07.jpg|Part of a dense band of 5th instar nymphs and young fledging of ''Schistocerca gregaria'' in Chad in 1988 (photo Michel Lecoq).
</gallery>

== References ==
{{Reflist}}

== Further reading ==
{{refbegin}}
*AFROL News, Stronger efforts to fight West Africa's locusts Oct. 1, 2004 [http://www.afrol.com/articles/14429 afrol News - Stronger efforts to fight West Africa's locusts]
*Lindsey, R. 2002. Locust![https://web.archive.org/web/20021101075847/http://earthobservatory.nasa.gov/Study/Locusts/locusts.html]
*{{cite journal |last1=Lomer |first1=C.J. |last2=Bateman |first2=R.P. |last3=Johnson |first3=D.L. |last4=Langwald |first4=J. |last5=Thomas |first5=M. |year=2001 |title=Biological Control of Locusts and Grasshoppers |journal=Annual Review of Entomology |volume=46 |pages=667–702 |doi=10.1146/annurev.ento.46.1.667|pmid=11112183 }}
*OECD, The Desert Locust Outbreak in West Africa – Sept. 23, 2004 [http://www.oecd.org/document/12/0,2340,en_2649_201185_33735052_119690_1_1_1,00.html The Desert Locust Outbreak in West Africa – OECD]
*Programme on biological control of locusts and grasshoppers (LUBILOSA) [https://web.archive.org/web/20080206212841/http://www.lubilosa.org/ Wayback Machine]
*Nature Magazine Article on combating desert locust through natural enemies [http://www.nature.com/nature/journal/v432/n7019/full/432801a_fs.html]
*Jahn, G. C. 1993. Supplementary environmental assessment of the Eritrean Locust Control Program. USAID, Washington DC. [https://web.archive.org/web/20130825105751/http://www.encapafrica.org/documents/PEA_pestmanagement/ERITREA_LG_SEA_MAR93.doc Wayback Machine]
*Abdin, O., Stein, A., van Huis, A., 2001. Spatial distribution of the desert locust, ''Schistocerca gregaria'', in the plains of the Red Sea coast of Sudan during the winter of 1999.
*van der Werf, W., Woldewahid, G., Abate, T., Butrous, M., Abdalla, O., Khidir, A. M., Mustafa, B., Magzoub, I., Abdin, O., Stein, A., & van Huis, A., 2002. Spatial distribution of the Desert Locust, ''Schistocerca gregaria'', in the plains of the Red sea coast of Sudan during the winter of 1999. In ''Conference on agricultural and environmental statistical applications / F. Piersimoni, Rome, 5–7 June 2001'' (pp.&nbsp;167–171).
*Ceccato, P., K. Cressman, A. Giannini, S. Trzaska. 2007. The desert locust upsurge in West Africa (2003–2005): Information on the desert locust early warning system and the prospects for seasonal climate forecasting. International Journal of Pest Management,  53(1): 7–13.  http://dx.doi.org/10.1080/09670870600968826
*Chapuis, M.P., Plantamp, C., Blondin, L., Pagès, C., Lecoq, M., 2014. Demographic processes shaping genetic variation of the solitarious phase of the desert locust. ''Molecular Ecology'' 23 (7): 1749–1763. https://doi.org/10.1111/mec.12687
*Cressman, K. 1996. Current methods of desert locust forecasting at FAO. Bulletin OEPP/EPPO Bulletin 26: 577–585. https://www.fao.org/ag/locusts/common/ecg/190/en/1996_EPPO_Cressman_Forecasting.pdf
*Cressman, K. 2008. The use of new technologies in Desert Locust early warning. Outlooks on Pest Management (April, 2008): 55–59. https://doi.org/10.1564/19apr03
*Cressman, K. 2013. Role of remote sensing in desert locust early warning. J. Appl. Remote Sens. 7 (1): 075098; https://doi.org/10.1117/1.JRS.7.075098
*Cressman, K. 2013. Climate change and locusts in the WANA Region. In M.V.K Sivakumar et al. (eds.), Climate Change and Food Security in West Asia and North Africa. (pp.&nbsp;131–143). Netherlands: Springer. https://doi.org/10.1007/978-94-007-6751-5_7
*Cressman, K. 2016. Desert Locust. In: J.F. Shroder, R. Sivanpillai (eds.), Biological and Environmental Hazards, Risks, and Disasters (pp.&nbsp;87–105). USA: Elsevier. https://www.fao.org/ag/locusts/common/ecg/190/en/1512_Bio_hazard_book_chapter.pdf
*Dinku, T., Ceccato, P., Cressman, K., and Connor, S.J. 2010. Evaluating detection skills of satellite rainfall estimates over Desert Locust recession regions. J Applied Meteorology and Climatology 49 (6): 1322–1332. https://doi.org/10.1175/2010JAMC2281.1
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{{refend}}

==External links==
*[http://www.fao.org/emergencies/crisis/desertlocust/en/ Desert Locust crisis in the Horn of Africa - FAO Website] {{Webarchive|url=https://web.archive.org/web/20210818212632/http://www.fao.org/emergencies/crisis/desertlocust/en/ |date=2021-08-18 }}
*[http://www.fao.org/ag/locusts FAO Locust Watch site]
*[https://web.archive.org/web/20080206212841/http://www.lubilosa.org/ Lubilosa site]
*[http://www.dropdata.net/biopesticides/green_muscle.htm Delivery systems]
*[http://www.livescience.com/animalworld/060601_locusts_swarm.html Why Locusts Swarm: A Study Finds 'Tipping Point']
*[http://iridl.ldeo.columbia.edu/maproom/.Food_Security/.Locusts/index.html Columbia University IRI Climate and Desert Locust] {{Webarchive|url=https://web.archive.org/web/20121221101804/http://iridl.ldeo.columbia.edu/maproom/.Food_Security/.Locusts/index.html |date=2012-12-21 }}
*[https://web.archive.org/web/20070106131148/http://www.ibimet.cnr.it/Case/sahel/infocus.php?page=mpp_main&cat=mpp Desert Locust Meteorological Monitoring, at Sahel Resources]
*[http://www.reptileexpert.org/breeding-locusts/ Cultivation of locusts for the pet trade]
*[https://ethos.bl.uk/OrderDetails.do?did=1&uin=uk.bl.ethos.370012 Modelling insect wings using the finite element method]

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{{Authority control}}

[[Category:Locusts]]
[[Category:Orthoptera of Africa]]
[[Category:Insects described in 1775]]
[[Category:Agricultural pest insects]]
[[Category:Food security]]
[[Category:Animal migration]]
[[Category:Orthoptera of Asia]]
[[Category:Insect pests of millets]]