“Tiny Jaws”: Locust Plagues in the Twentieth Century and Beyond

By Christian Ruth

A Gnawing Threat

Locusts are plagues. When one imagines a swarm of locusts, images of dusky, swift-moving clouds of insects come to mind. This is, of course, accurate. Plagues of locusts will blanket the sky, blinding lines of sight and reducing visibility to well below a mile. A square kilometer of land can contain upwards of fifty million locusts. But locusts are, perhaps most disconcertingly, hungry. A single group such as this is capable of consuming over a hundred thousand pounds of vegetation.[1] And they are loud. Together, billions of locusts produce the frenzied sound of “millions of tiny jaws grinding and chewing, as if someone were scraping a carrot.”[2] True plagues, they can spread across hundreds of kilometers, resulting in catastrophic levels of deforestation and crop eradication as the swarms move across the land, breeding and feeding. Locust swarms are not locked to specific regions of the world, but instead migrate hundreds or even thousands of miles in favorable conditions.[3] With favorable winds, they can travel across oceans. They are a truly global pest.[4]

Climate change is projected to severely exacerbate the severity of weather conditions around the world, but there is growing consensus that it is also currently affecting the frequency and strength of some dangerous animal habits. Rising temperatures and changing rain patterns have altered the migratory habits of many species, resulting in invasive species acting particularly aggressive and disrupting long-established ecosystems.[5] Locusts are one such species affected by climate change with disastrous results to the health of human populations. In the twentieth century, locust plagues have both exacerbated existing food crises and created new ones. Major plague occurrences have declined over the past sixty years due to better pesticide quality and availability; but despite increasingly powerful efforts by international agencies, locusts have still been highly problematic.[6] Historically, these plagues have been dealt with by influxes of aid by Western nations, but with current crises and donor fatigue setting in, not to mention a reticent White House that is combative towards climate change legislation, how will the world cope? A history lesson can be useful in providing greater context when thinking about these questions. 

Locusts in the “Land of the Damned”

Compared to the rest of the world, the continent of Africa has suffered more frequently and severely compared to other regions of the world from locust plagues, especially desert locust plagues. Locust plagues are common throughout the northern half of the continent, particularly in the Horn of Africa and across the Sahel. These plagues often complicate the existing civil, humanitarian and environmental disasters on the continent, making these crises worse by eating up resources and damaging agricultural infrastructure. Western nations have been aware of the unrest and economic damages that locusts wreak on African nations, and since the earliest parts of the twentieth century many countries, including the United States and the United Kingdom, have spent hundreds of millions of dollars trying to eradicate and control African plagues as they are discovered.

By the time that locusts began swarming in Africa during the late 1980s, journalists had become used to describing apocalyptic food scarcity scenarios on the continent. Since the early 1960s, Africa had seen several large-scale famines resulting from combinations of drought, civil strife and war. Headlines described “Days and Nights of Suffering” in the “Land of the Damned” and the “Land of Want,” as hundreds of thousands of men, women and children starved to death.[7] International aid efforts by powerful donors such as the United States and UN relief organizations had been active for some time, responding to various crises across the beleaguered continent, especially in the Horn of Africa and across the nations of the Sahel. [8]

Pre-existing Crises

Severe famine conditions occurred throughout these regions in the early 1980s, most notably in Sudan and Ethiopia, as lack of rainfall and internecine warfare in several nations resulted in major refugee crises that created well over a million displaced people.[9] There was a full-throated international response to the first round of famine, which lasted from 1983 to 1986. Likewise, the United States and allied nations, through the UN and many private aid groups such as the Red Cross, funneled fifty million dollars into these nations to stave off the famine.[10] Unfortunately, famine returned shortly after initial drought conditions improved. In 1987, lack of rainfall and civil unrest caused famine throughout North Africa, particularly in the Horn region.[11] Compounding these problems was the rising tide of locusts that threatened to overwhelm relief efforts and plunge a substantial portion of Africa into disaster conditions.

How do Plagues Form

The 1980s African desert locust plague arose not out of drought, as one might think, but rainfall. Most locust species, including the desert locust, exist in a cycle of breeding that relies on placing their eggs in a suitably damp environment. The desert locust, having no protection for their offspring from arid climates, is forced to migrate to areas of recent rainfall to spawn their newborns.[12] Desert locust plagues arise most commonly when there is a period of relative dry weather followed by repeated rainfall. Locusts will flock to these newly dampened regions, breeding and laying eggs in large numbers, and “gregarizing,” as scientists refer to it. Desert locusts that gregarize will become more and more active when in the presence of other locusts, a quality that scientists refer to as being gregarious. Gregarizing behavior causes locusts to swarm more and more, which results in increased numbers of locusts being born, which simply feeds the cycle until a plague is created.[13] Gregarious phases resulting in swarms cause the swarms to spread out to find new land in which to lay eggs, causing the plagues to spread across thousands of miles of land as the locusts eat and move to find suitable new soil to breed. The only hindrance to their migrations are natural weather conditions, usually fierce winds or particularly strong heat waves that blow them off track and ruin breeding grounds, or manmade efforts.[14]

Plague Responses

Barring divine intervention in the form of weather, humanity has struggled to track and handle the threat that locust swarms have presented. In the twentieth century, international coordination on locust swarms began during the late 1920s and early 1930s, as British entomologists dealt, ironically, with desert locust plagues in East Africa.[15] The Committee on Locust Control was created as a formal part of the British government to mitigate the threat in Commonwealth nations, but it expanded rapidly to combat locust issues around the world. In 1945 the Anti-Locust Research Centre (ALRC) was created as an independent entity, a newly formed agency to replace the original Committee on Locust Control due to a lack of money following the Second World War. The Centre organized international monitoring groups to keep track of locust populations and to alert for possible plagues; many of these monitoring groups still exist today. These regional institutions correspond to large areas of land, covering multiple nations and are targeted toward specific locust species. In the 1950s, the Food and Agriculture Organization of the United Nations (FAO), along with several member states, created the Desert Locust Information Service (DLIS), which is still a vital resource for tracking possible plagues and implementing pesticide in appropriate areas.[16]

Climate Change and the Future

Unfortunately, climate change is affecting these long-established systems. In recent years there have been several locust plagues around the world, touching most continents beyond Africa.[17] Annual plagues are forecasted to become more powerful, as global temperatures rise and rainfall-drought cycles become more pronounced.[18] Wind levels and patterns will change over time as well, exacerbated by climate change, which dramatically affects how far and in what direction locusts migrate.[19] Monitoring groups rely upon ground tracking as well as satellite imagery to track potential swarms, so that they can target their eradication efforts most effectively. But these forecasts and the models they rely on are being disrupted by the altering climate, causing recent predictions to be inaccurate or delayed.[20]

Looking ahead, scientists are already rapidly trying to assess what changes need to be made to their methods of handling locust plagues. Efforts to react and curtail climate change are underway and should, of course, continue. It is important, however, for the wider global population to appreciate how much a changing climate affects the living things that inhabit the Earth. Beyond the polar bears and more relatable adorable animals, the pests of the world will also undergo change in the decades ahead as the climate continues to alter. In many ways, it is the way that these hated, destructive animals adapt that will dictate the lives of millions. Perhaps such a change in perspective will change how people think about the impact of climate change overall.


Christian Ruth is a History PhD student at the University at Albany, SUNY. He received his BA and MA in History at the University of Kentucky. His research focuses on the intersection of US Foreign Policy and Environmental History during the twentieth century to the present, particularly in Africa.


[1]Paul Lewis, “Locusts Head South, Threaten New African Famine,” New York Times, April 24, 1988.

[2] The Anniston Star, October 8, 1969.

[3] J. Draper, “The Direction of Desert Locust Migration.” Journal of Animal Ecology, 49 (1980), 961.

[4] U.S. Congress, Office of Technology Assessment, A Plague of Locusts-Special Report OTA F-450 (Washington, DC: U.S. Government Printing Office, July 1990), 5.

[5] Both plant and animal species are affected by the changing global climate. See Anna Szyniszewska, “Invasive Species and Climate Change,” Climate Institute, permanent url: http://climate.org/archive/topics/ecosystems/invasivespecies.html

[6] There are so many swarm warnings of locusts that measuring the sheer number of times that they have been damaging is difficult. True plagues, defined by locusts reaching a certain critical mass of population density and acreage covered, are less common but still quite numerous. There have been a high number of recorded plagues in the twentieth century: in 1915, a particularly devastating plague in Palestine resulted in the region losing practically all of its vegetation, desert locusts have swarmed to plague levels throughout Africa in 1926-1934 in 1940-1948, 1949-1963, 1967-1969, and 1986-1989, causing widespread damage in the billions of dollars. Other locust species beside the desert locust swarm to plague levels as well in other regions of the world, but this piece will focus primarily on the desert locust.

[7] Memorandum from the President’s Assistant for National Security Affairs (Brzezinski) to President Carter. Washington, January 12, 1978. Foreign Relations of the United States 1977-1980. Volume I: Foundations of Foreign Policy, 287.

[8] The Sahel encompasses all or parts of many nations, including Senegal, Mauritania, Mali, Burkina Faso, Algeria, Niger, Nigeria, Chad, Sudan, South Sudan, Eritrea, Cameroon, Central African Republic and Ethiopia. The Horn of Africa is typically defined as including Sudan, Ethiopia, Somalia, Eritrea and Djibouti. There is overlap between these two geographic regions, and maps tend to conflate them, especially regarding Sudan and Ethiopia. See New York Times, “Famine in Ethiopia: Days and Nights of Suffering; Famine in Ethiopia: Barren Hills, Exhausted People; A Land of Want.” December 18, 1984.

[9] Ethiopia and Sudan one year later: refugee and famine recovery needs: a minority staff report / prepared for the use of the Subcommittee on Immigration and Refugee Policy to the Committee on the Judiciary, United States Senate. 3

[10] Julia V. Taft, Assistant Administrator, Action Memorandum for the Administrator: Regulation 16 Emergency Determination for Sudan Locust Control, Washington D.C., July 7, 1988. Project Locust Outbreak, Fiscal Year 1986, Sudan, Declared 6/25/1986. Project Files 1981-1998, Africa Civil Strife, Fiscal Year 1986 through Asia and the Pacific, Philippine Floods Fiscal Year 1986, Container #18. General Records of the United States Agency for International Development, the Office of Foreign Disaster Assistance, Record Group 0286. National Archives and Records Administration, College Park, MD.

[11] Ethiopia and Sudan: warfare, politics, and famine: hearing before the Select Committee on Hunger, House of Representatives, One Hundredth Congress, second session, hearing held in Washington, DC, July 14, 1988. 1.

[12] R. Skaf, G. B. Popov, J. Roffey, R. S. Scorer and J. Hewitt, “The Desert Locust: An International Challenge and Discussion,” Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, Vol. 328, No. 1251, Migrant Pests: Problems, Potentialities and Progress (Jun. 30, 1990), 525-538.

[13] P. T. Haskell, “International Locust Research and Control,” Journal of the Royal Society of Arts, Vol. 119, No. 5176 (March, 1971), 255.

[14] Paul Lewis, “Locusts Head South, Threaten New African Famine,” New York Times.

[15] Haskell, “International Locust Research and Control,” 259.

[16]See the FAO’s official website for the DLIS: http://www.fao.org/ag/locusts/en/info/info/index.html

[17] See https://www.nytimes.com/2016/01/26/world/americas/argentina-scrambles-to-fight-biggest-plague-of-locusts-in-60-years.html?mcubz=1; http://www.dw.com/en/locust-swarms-trigger-state-of-emergency-in-bolivia/a-37466641; http://www.express.co.uk/news/world/675140/Locusts-Russia-Dagestan-plague; https://motherboard.vice.com/en_us/article/ywg4v5/oh-look-russias-annual-plague-of-locusts-is-here for a few examples.

[18] Christine N. Meynard et al. Climate-driven geographic distribution of the desert locust during recession periods: Subspecies’ niche differentiation and relative risks under scenarios of climate change, Global Change Biology (2017).

[19] https://www.theguardian.com/environment/2013/may/23/insects

[20] https://phys.org/news/2017-09-locustsnew-climate.html

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: