Desert locust outbreak declared over by the United Nations -- What’s next?

By Mira Word RiesGlobal Locust Initiative

Desert locust outbreak Sven Torfinn
31 March 2020, Kipsing, near Oldonyiro, Isiolo county - A desert locusts swarm flies in the region. ©FAO/Sven Torfinn.

The phenomenon of a desert locust outbreak has long struck fear in the hearts of farmers and pastoralists. Swarms that obscure the sun and stretch for kilometers, can easily devour the hopes of a plentiful harvest. From late 2019 into 2022, the Greater Horn of Africa, the Arabian Peninsula, and parts of southwest Asia, experienced a severe desert locust (Schistocerca gregaria) outbreak. Many of the 23 countries impacted had not seen an upsurge of this magnitude in decades. For Kenya, it was the worst in 70 years. In conjunction with other disasters like drought, flooding, armed conflict, and a pandemic, over 36 million people faced crisis-level food insecurity in locust-affected countries (as of May 2021). On March 2, 2022, the Food and Agriculture Organization of the United Nations (FAO) officially declared the outbreak was over.

The FAO and its partners raised more than 243 million USD to mobilize control efforts, from surveillance to rapid support for countries scrambling to resurrect eroded response systems. Aerial operations treated desert locusts across 2.3 million ha in the Horn of Africa and Yemen since January 2020. FAO reports these efforts averted 4.6 million metric tonnes of crop losses, saved 900 million liters of milk production, and secured food for nearly 42 million people. The commercial value of the cereal and milk loss averted is estimated at USD 1.8 billion. However, the complex interplay of tradeoffs that accompany the widespread use of organophosphates and pyrethroid pesticides is understudied and could be felt for generations to come. Among the affected countries, Somalia was alone in exclusively using biopesticides and insect growth regulators (IGRs), which are slower acting and much less harmful to non-target organisms and human health than synthetic pesticides.

During the outbreak, the Global Locust Initiative (GLI) fielded dozens of media requests for expert interviews and questions from concerned citizens and stakeholders. The GLI team provided information for seventeen published articles from the National Geographic to The New York Times and NPR. We connected network members around the world and shared resources by providing a platform for posts from the field and real-time discussion. The GLI Lab is also actively studying what factors affect the swarming capacity and pathogen susceptibility of the desert locust, as part of the larger NSF Behavioral Plasticity Research Institute.

The general patterns of human response to locust outbreaks are often characterized as a ‘vicious cycle’, or an alternation between two phases: a motivation phase in the face of emergency, and an oblivion phase during recession times. While other disasters like pandemics, floods, and wildfires share similar dynamics, the unique biology and migration capacity of locusts make them a particularly dramatic example. During the motivation phase, actors are engaged in aggregating and directing resources, time, and energy to stop the spread of locusts. Capacity is built, plans are formulated, and action is taken. Once locust populations have decreased and the outbreak subsides, memory fades and the cycle shifts to the oblivion phase, characterized by a lack of motivation, decreased resources, and a lack of involved organizations and specialists, etc.

Locusts outbreaks are embedded in a complex social-ecological-technical-system (SETS) and therefore impact the work of diverse organizations. In the midst and aftermath of an outbreak, we see the emergence of new partnerships and ideas to improve a multitude of factors from early warning, to forecasting, and relief distribution. As human attention and resources are moved elsewhere out of necessity or fading interest, a critical question emerges: will we slip back into the oblivion phase of the vicious cycle? In the aftermath of an outbreak of this scale much work remains to document lessons learned, highlight achievements, and evaluate obsolete technologies and practices that no longer serve collective values.

If you have ideas on how to help avoid the oblivion phase of locust outbreaks, join the conversations happening in our private professional network for the Global Locust Initiative.

FAO (2020) Real-time evaluation of FAO’s response to desert locust upsurge (2020-2021) – Phase 1. Programme Evaluation Series, 12/2020. Rome.

FAO (2021) Desert locust upsurge – Progress report on the response in the Greater Horn of Africa and Yemen, May–August 2021. Rome.

FAO. 2022. Desert locust upsurge – Progress report on the response in the Greater Horn of Africa and Yemen, September–December 2021. Rome.

Gay P, Lecoq M, Piou C (2020) The limitations of locust preventive management faced with spatial uncertainty: Exploration with a multi-agent model. Pest Management Science. 76: 1094–1102

Lecoq M, Lecoq M (1991) Le Criquet pèlerin. Enseignements de la dernière invasion et perspectives offertes par la biomodélisation. In La Lutte Anti-Acridienne; AUPELF-UREF, John Libbey Eurotext: Paris, France. 71–98.

Pesticide Referee Group. (2014) Evaluation of field trails data on the efficacy and selectivity. Gammarth (Tunisia). FAO. pp 66.

Therville C, Anderies JM, Lecoq M, Cease A (2021) Locusts and People: Integrating the Social Sciences in Sustainable Locust Management. Agronomy 11: 951.