By Mira Ries—Global Locust Initiative
Above-average rainfall across many parts of Southern Africa has allowed populations of the Brown Locust (Locustana pardalina) to skyrocket. Initial outbreaks started in 2020 in the eastern and south-eastern Karoo, the region endemic to the Brown Locust. The usually arid Karoo has transformed into a lush oasis, causing South African farmers to trade the hardship of drought for the task of managing the worst outbreak in the last ten years.
Brown Locust outbreaks are a consistent natural phenomenon brought about by plentiful summer rains. Their outbreak zone covers approximately 250,000 km2 of the Karoo, extending out of South Africa into southern Namibia. In the past, plagues have developed that span the entire southern African sub-continent up to the Zambezi River. Periodic upsurges are known to spread further into Namibia, Botswana, and Zimbabwe, and to a less documented extent, into Zambia, Mozambique, and Angola. To date, this current outbreak is primarily impacting South Africa and Namibia, with some 2021 reports in Botswana and Angola.
One of the most challenging aspects of controlling the Brown Locust—as well as other species like the Desert Locust (Schistocerca gregaria)—is that their breeding grounds are in remote and rugged regions of the world. The best time to spray dense populations of locusts is in their immature wingless stages as nymphs. However, getting locust teams into the Karoo for example, and streamlining communication between farmers, land managers, and government officials remains difficult. 80 million rand (5.4 million USD) has been spent on control operations so far with a heavy reliance on broad-spectrum pyrethroid insecticides. Although there are calls for turning to alternative forms of integrated pest management like the biopesticide Green Muscle® as well as techniques like barrier spraying to reduce harmful impacts on non-target species.
While reports of swarms are decreasing in the Western Cape of South Africa, efforts continue to push for a national disaster declaration as Eastern Cape could be hit next. Namibia has been contending with both the Brown and Red Locust (Nomadacris septemfasciata) since late 2021. The Namibian reports that in 10 of the country's 14 regions, the locusts have destroyed over 719,000 hectares of grazing land and 1,207 hectares of crop fields, with the Kharas region being the worst affected.
If you are interested in learning more about the Brown Locust or have more information on the current situation please get in touch with the Global Locust Initiative.
Watch videos of the Brown Locust outbreak:
Karoo in crisis as locust swarms decimate crops, Herald Live Apr 16, 2021
Locusts in the Karoo 1, SA People Mar 16, 2022
Locusts in the Karoo 2, SA People Mar 16, 2022
Here are some of the management and research organizations involved in controlling the Brown Locust:
* The South African National Biodiversity Institute (SANBI)
* CropLife Africa Middle East
* Agri SA
* The Grootfontein Agricultural Development Institute
* National Agricultural Marketing Council NAMC
* FAO Subregional Office for Resilience in West Africa and the Sahel
* Agri Northern Cape
* Croplife South Africa
* The Department of Agriculture, Land Reform and Rural Development
* Western Cape Department of Agriculture
* Free State Department: Agriculture and Rural Development
References
Albertz, Ellen. “Locust swarms wreak havoc at Keetmanshoop.” The Namibian, 04/06/2022 https://www.namibian.com.na/111471/read/Locust-swarms-wreak-havoc-at-Keetmanshoop
Chaslyn Chetty, Reeshni. “Plague of locusts enters NC – is SA prepared for an ‘epidemic’?” The South African, 11/03/2022 https://www.thesouthafrican.com/news/locusts-outbreak-northern-cape-spreading-farms-11-march-2022/
COPR (1982) The Locust and Grasshopper Agricultural Manual. London: Overseas Pest Research. 473-477.
Coleman, Annelie. “Brown locust outbreaks threaten Southern Africa.” Farmer’s Weekly 03/14/2021 https://www.farmersweekly.co.za/agri-news/africa/brown-locust-outbreaks-threaten-southern-africa/
Lea A (1958) Recent outbreaks of the brown locust, Locustana pardalina (Walk), with special reference to the influence of rainfall. Journal of the Entomological Society of Southern Africa 21: 162–213. https://doi.org/10.10520/AJA00128789_4047
Nefdt, Ashleigh. “Locust crisis in SA should be a national disaster, according to the WC.” CApe Town etc., 4/6/2022 https://www.capetownetc.com/news/locust-crisis-in-sa-should-be-a-national-disaster-according-to-the-wc/
Price R (2021) Alternative Strategies for Controlling the Brown Locust, Locustana pardalina (Walker). Agronomy 11: 2212. https://doi.org/10.3390/agronomy11112212
SAPeople Contributor. “WATCH Locusts Swarm Karoo Skies in Biblical Proportions, and Wreak Havoc on Crops.” SA People News, 03/16/2022 https://www.sapeople.com/2022/03/16/watch-locusts-swarm-karoo-skies-in-biblical-proportions-and-wreak-havoc-on-crops/
Sgqolana, Tembile. “SA farmers battle to control locust swarms of biblical proportions.” Daily Maverick, 03/15/2022 https://www.dailymaverick.co.za/article/2022-03-15-sa-farmers-battle-to-control-locust-swarms-of-biblical-proportions/
Sgqolana, Tembile. “Swarms of brown locusts plague three provinces despite R80m spent on fighting the outbreak.” Daily Maverick, 04/08/2022 https://www.dailymaverick.co.za/article/2022-04-08-swarms-of-brown-locusts-plague-three-provinces-despite-r80m-spent-on-fighting-the-outbreak/
Steedman A (1990) Other African locusts. In: Locust Handbook. Natural Resources Institute, Chatham, 204.