Editing Grasshopper (section)

===Swarming===
{{main|Locust}}
[[File:CSIRO ScienceImage 7007 Plague locusts on the move.jpg|thumb|left|upright=1.2|Millions of [[Australian plague locust|plague locusts]] on the move in Australia]]

Locusts are the swarming phase of certain species of short-horned grasshoppers in the family Acrididae. Swarming behaviour is a response to overcrowding. Increased tactile stimulation of the hind legs causes an increase in levels of [[serotonin]].<ref>{{cite news |url=http://news.bbc.co.uk/2/hi/science/nature/7858996.stm |work=BBC News |author=Morgan, James |title=Locust swarms 'high' on serotonin |date=29 January 2009 |access-date=31 March 2015 |url-status=live |archive-url = https://web.archive.org/web/20131010043157/http://news.bbc.co.uk/2/hi/science/nature/7858996.stm|archive-date = 10 October 2013}}</ref> This causes the grasshopper to change colour, feed more and breed faster. The transformation of a solitary individual into a swarming one is induced by several contacts per minute over a short period.<ref>{{cite journal |author1=Rogers, Stephen M. |author2=Matheson, Thomas |author3=Despland, Emma |author4=Dodgson, Timothy |author5=Burrows, Malcolm |author6=Simpson, Stephen J. |year=2003 |title=Mechanosensory-induced behavioral gregarization in the desert locust ''Schistocerca gregaria'' |journal=[[Journal of Experimental Biology]] |volume=206 |issue=22 |pages=3991–4002 |doi=10.1242/jeb.00648 |pmid=14555739 |s2cid=10665260 |url=http://jeb.biologists.org/content/jexbio/206/22/3991.full.pdf |url-status=live |archive-url=https://web.archive.org/web/20160924005950/http://jeb.biologists.org/content/jexbio/206/22/3991.full.pdf |archive-date=24 September 2016 |doi-access=free }}</ref>

Following this transformation, under suitable conditions dense nomadic bands of flightless nymphs known as "hoppers" can occur, producing [[pheromone]]s which attract the insects to each other. With several generations in a year, the locust population can build up from localised groups into vast accumulations of flying insects known as plagues, devouring all the vegetation they encounter. The [[Albert's swarm|largest recorded locust swarm]] was one formed by the now-extinct [[Rocky Mountain locust]] in 1875; the swarm was {{convert|1800|mi}} long and {{convert|110|mi}} wide,<ref>{{cite news |title=Looking Back at the Days of the Locust |author=Yoon, Carol Kaesuk |url=https://www.nytimes.com/2002/04/23/science/looking-back-at-the-days-of-the-locust.html |newspaper=New York Times |date=23 April 2002 |access-date=31 March 2015 |url-status=live |archive-url=https://web.archive.org/web/20150403092454/http://www.nytimes.com/2002/04/23/science/looking-back-at-the-days-of-the-locust.html |archive-date=3 April 2015 }}</ref> and one estimate puts the number of locusts involved at 3.5 trillion.<ref name=Lockwood>{{cite book|last=Lockwood |first=Jeffrey A. |title=Locust: the Devastating Rise and Mysterious Disappearance of the Insect that Shaped the American Frontier |year=2004 |publisher=Basic Books |isbn=0-7382-0894-9 |page=21 |edition=1st}}ffol</ref> An adult [[desert locust]] can eat about {{convert|2|g|1|abbr=on}} of plant material each day, so the billions of insects in a large swarm can be very destructive, stripping all the foliage from plants in an affected area and consuming stems, flowers, fruits, seeds and bark.<ref name=Capinera1181/>