Editing Locust (section)

==Distribution and diversity==

{{main|List of locust species}}

{{multiple image
|total_width=500
|image1=SGR laying.jpg
|caption1=Desert locust [[Ovipositor|ovipositing]] during a locust outbreak
|image2=Locust-eggs Palestine 1930 composite coloured.jpg
|caption2=Clusters of desert locust eggs laid in sand
}}

Several species of [[grasshopper]]s swarm as locusts in different parts of the world, on all continents except Antarctica:<ref name=SciAm-Swarming>{{cite magazine |last1=Harmon |first1=Katherine |title=When Grasshoppers Go Biblical: Serotonin Causes Locusts to Swarm |url=http://www.scientificamerican.com/article/when-grasshoppers-go-bibl/ |magazine=[[Scientific American]] |access-date=7 April 2015 |date=30 January 2009}}</ref><ref name=Wagner>{{cite journal |author=Wagner, Alexandra M. |title=Grasshoppered: America's response to the 1874 Rocky Mountain locust invasion |url=https://history.nebraska.gov/sites/history.nebraska.gov/files/doc/publications/NH2008Grasshoppered.pdf |journal=Nebraska History |volume=89 |issue=4 |pages=154–167 |date=Winter 2008 |access-date=2 March 2020 |archive-date=15 April 2021 |archive-url=https://web.archive.org/web/20210415021930/https://history.nebraska.gov/sites/history.nebraska.gov/files/doc/publications/NH2008Grasshoppered.pdf |url-status=dead }}</ref><ref>{{cite news |last1=Yoon|first1=Carol Kaesuk |title=Looking Back at the Days of the Locust |url=https://www.nytimes.com/2002/04/23/science/looking-back-at-the-days-of-the-locust.html |newspaper=[[The New York Times]] |access-date=1 April 2015 |date=23 April 2002}}</ref>{{efn|The [[Schistocerca americana|American locust]] (''Schistocerca americana'') does not swarm.<ref name=thomas>Thomas, M. C. ''The American grasshopper, ''Schistocerca americana americana'' (Drury) (Orthoptera: Acrididae)''. Entomology Circular No. 342. Florida Department of Agriculture and Consumer Services. May 1991.</ref>}} For example, the [[Australian plague locust]] (''Chortoicetes terminifera'') swarms across Australia.<ref name=SciAm-Swarming/>

The [[desert locust]] (''Schistocerca gregaria'') is probably the best known species owing to its wide distribution ([[North Africa]], [[Middle East]], and [[Indian subcontinent]])<ref name=SciAm-Swarming/> and its ability to [[Animal migration|migrate]] over long distances. A [[2004 Africa locust infestation|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.<ref>{{cite web |title=FAO issues Desert Locust alert: Mauritania, Niger, Sudan and other neighbouring countries at risk |url=http://www.fao.org/english/newsroom/news/2003/24019-en.html |publisher=Food and Agriculture Organization |access-date=3 July 2015 |location=Rome |date=20 October 2003 |archive-date=31 March 2017 |archive-url=https://web.archive.org/web/20170331112729/http://www.fao.org/english/newsroom/news/2003/24019-en.html |url-status=dead }}</ref><ref>{{cite web|title= Desert Locusts Plague West Africa|url=https://www.npr.org/templates/story/story.php?storyId=4168375|publisher=NPR|work = Morning Edition|date=15 November 2004}}</ref> Swarms crossed Africa, appearing in Egypt, Jordan and Israel, the first time in those countries for 50 years.<ref>{{cite web |title=Desert Locust Archives 2003 |url=http://www.fao.org/ag/locusts/en/archives/archive/1366/2003/index.html |publisher=Food and Agriculture Organization |access-date=3 July 2015}}</ref><ref>{{cite web |title=Desert Locust Archives 2004 |url=http://www.fao.org/ag/locusts/en/archives/archive/1366/2004/index.html |publisher=[[Food and Agriculture Organization]] |access-date=3 July 2015}}</ref> The cost of handling the infestation was put at US$122&nbsp;million, and the damage to crops at up to $2.5&nbsp;billion.<ref>{{cite web |title=The Desert Locust Outbreak in West Africa |url=http://www.oecd.org/general/thedesertlocustoutbreakinwestafrica.htm |publisher=OECD |access-date=3 July 2015 |date=23 September 2004}}</ref>

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.<ref name=Chapuis>{{cite journal |last=Chapuis |first=M-P. |author2=Lecoq, M. |author3=Michalakis, Y. |author4=Loiseau, A. |author5=Sword, G. A. |author6=Piry, S. |author7= Estoup, A. |title=Do outbreaks affect genetic population structure? A worldwide survey in a pest plagued by microsatellite null alleles |journal=Molecular Ecology |date=1 August 2008 |volume=17 |issue=16 |pages=3640–3653 |doi=10.1111/j.1365-294X.2008.03869.x |pmid=18643881|s2cid=4185861 |url=http://agritrop.cirad.fr/545307/ }}</ref> [[2013 Madagascar locust infestation|In 2013, 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.<ref>{{cite news |last=Botelho |first=Greg |title=Plague of locusts infests impoverished Madagascar |date=28 March 2013 |publisher=[[CNN]] |url=http://www.cnn.com/2013/03/27/world/africa/madagascar-locusts |access-date=29 March 2013}}</ref> 
Species such as the [[Senegalese grasshopper]] (''Oedaleus senegalensis'')<ref name=Uvarov>{{cite book |last=Uvarov |first=B.P. |year=1966 |title=Grasshoppers and Locusts (Vol. 1) |publisher=Cambridge University Press |chapter=Phase polymorphism}}</ref> and the [[Hieroglyphus daganensis|African rice grasshopper]] (''Hieroglyphus daganensis''), both from the [[Sahel]], often display locust-like behaviour and change morphologically on crowding.<ref name=Uvarov/>

North America is the only sub-continent besides Antarctica without a native locust species. The [[Rocky Mountain locust]] was formerly one of the most significant insect pests there, but it became extinct in 1902.<ref>''[[Canada's History]]'', October–November 2015, pages 43-44</ref> 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.<ref name="Wills 2018a">{{cite web |url=https://daily.jstor.org/the-long-lost-locust/ |title=The Long-Lost Locust |last= Wills |first= Matthew
|date=14 June 2018 |website= JSTOR Daily |access-date= October 5, 2020 |quote=...the High Plains locust (''Dissosteira longipennis''), which swept through the early 1930s...}}</ref><ref name="Wills 2018b">{{cite web |url=https://daily.jstor.org/the-long-lost-locust/ |title= The Long-Lost Locust |last=Wills |first= Matthew |date=14 June 2018 |website=JSTOR Daily |access-date= October 5, 2020 |quote=The High Plains locust still exists, but it's uncommon, just another innocent-looking grasshopper munching away on plants.}}</ref>

=== Evolution ===
The fossilized wing of an indeterminate locust has been found in [[Rupelian|Early Oligocene]]-aged sediments of the [[Pabdeh Formation]] in [[Iran]], which were deposited in a deep marine environment. The locust was likely migrating across the early [[Paratethys|Paratethys Sea]], between the emergent Arabian Peninsula and central Iran, which were still separated by large areas of deep ocean at this time. This suggests that trans-oceanic locust migrations have been occurring for at least 30 million years, likely facilitated by the spread of [[Grassland|grasslands]] at the time.<ref>{{Cite journal |last1=Mirzaie Ataabadi |first1=Majid |last2=Bahrami |first2=Ali |last3=Yazdi |first3=Mehdi |last4=Nel |first4=André |date=2019-05-28 |title=A locust witness of a trans-oceanic Oligocene migration between Arabia and Iran (Orthoptera: Acrididae) |url=https://www.tandfonline.com/doi/full/10.1080/08912963.2017.1378651 |journal=Historical Biology |language=en |volume=31 |issue=5 |pages=574–580 |doi=10.1080/08912963.2017.1378651 |bibcode=2019HBio...31..574M |issn=0891-2963}}</ref>