Brown locust (Locustana pardalina)

Locustana pardalina
Other common names
Bruinsprinkaan (Afrikaans)
Taxonomic classification
Suborder:	Caelifera
Family:	Acrididae
Subfamily:	Oedipodinae
Tribe:	Locustini
Genus:	Locustana
Scientific name
Locustana pardalina (Walker, 1870)
Geography
Native countries:
Botswana Lesotho Namibia South Africa
Pest status
Known pest

The brown locust (Locustana pardalina) is a highly gregarious species and one of the most important agricultural pests in southern Africa, where recurrent upsurges and plagues have shaped farming and rangeland management for over a century. Native to the semi-arid Nama Karoo and adjoining arid grasslands, it periodically forms dense hopper bands and swarms that can severely impact grazing and crops. Its life history is closely tied to variable rainfall of this area, with drought-tolerant eggs and rapid population growth after good rains driving shifts from low-density solitarious populations to gregarious upsurges.

Taxonomy

For full nomenclature and taxonomic details of this taxon, see Orthoptera Species File No subspecies recorded for this taxon.

Identification

The brown locust is part of the subfamily Cyrtacanthacridinae which contains many of the world’s most notorious locusts. These grasshoppers are typically large-bodied, strong fliers, and capable of forming swarms under favorable environmental conditions. Their ability to switch between solitary and gregarious phases, known as phase polyphenism, underlies their capacity for sudden population outbreaks. Important locust species include the desert locust (Schistocerca gregaria), the red locust (Nomadacris septemfasciata), the South American locust (Schistocerca cancellata), the Central American locust (Schistocerca piceifrons), the Bombay locust (Patanga succincta), the Sahelian tree locust (Anacridium melanorhodon), and the migratory locust (Locusta migratoria). Many of these species are adapted to arid and grassland environments across Africa, Asia, and Australia, where periodic rainfall can trigger rapid breeding and swarm development.

Brown locust hopper ©M. Keiser

Morphologically, Cyrtacanthacridinae species are distinguished by the presence of a prosternal spine and robust hind femora adapted for jumping. Wing coloration, often featuring bright hindwings with yellow, red, or rose tones, serves as a key diagnostic feature.

Identification details

Gregarious adult brown locust ©M. Keiser 2006

The brown locust is an endemic pest of southern Africa that exhibits pronounced phase polyphenism, from highly solitary to highly gregarious forms, with clear intermediate stages. Solitary nymphs are cryptically colored green, grey, or brown, while gregarious hoppers are initially jet black and later develop a characteristic orange-and-black “red coat” with a distinct black patch on each side of the pronotum. Solitary adults are smaller (about 28–40 mm), generally grey-brown and sometimes tinged with green, with mottled black patches on the forewings. Gregarious adults are larger (about 42–50 mm), rusty brown with black bands on the forewings, and have blue‑tinted underwings that become conspicuous in flight.

Identification resources

Title	Author(s)	Year	Geographic purview	URL
FAO locust handbook identification key	FAO Desert Locust Information Service and Food and Agriculture Organization of the United Nations			View URL

Distribution

Brown locust outbreak region and invasion area.

The brown locust occurs in Angola, Zambia, Namibia, South Africa, Zimbabwe, Mozambique, and Botswana. It is native to the semi-arid Nama Karoo regions of South Africa, southern Namibia, and south-western Botswana. Historically its swarms have occasionally spread across much of southern Africa, reaching as far north as the Zambezi River.

For more information and distribution records see [GBIF]

Biology and ecology

The brown locust is highly adaptable, an essential trait for survival in its erratic, semi‑arid environment. The multivoltine lifecycle and high fecundity of this species make rapid population increase possible. Under favorable conditions it can produce three to four generations in a single season, whereas under drought conditions, eggs may enter diapause or quiescence and persist in the soil for years depending on soil moisture levels.

5th instar gregarious phase brown locust hoppers ©ARC

Brown locust eggs occur in two functional types: some hatch in roughly 10–20 (or sooner, 14 days after 20–25 mm of rainfall) days when moisture is adequate, while others enter diapause for one to three months or longer, and both types can occur in a single pod. Each pod can contain diapause or nondiapause eggs or a mixture depending on the mother's phase state. Solitary or older females lay mostly diapause eggs, while gregarious lay a higher percentage of non-diapause which hatch into nymphs with gregarious characteristics.

A secondary wax layer or membrane and specialized hydropyle cells that actively absorb moisture from the soil, rather than relying on osmosis, are what make brown locust eggs so drought-resistant. The protein layer around the hydropyle and the wax layer covering the rest of the egg effectively prevent water loss, allowing the embryo to retain absorbed moisture and pause development until soil moisture is sufficient, without drying out during drought conditions. in In addition to the egg's desiccation resistance, L. pardalina embryos can arrest and delay development, known as quiescence, in direct response to insufficient moisture. What makes the brown locust unique is that its embryos can repeatedly enter and exit the quiescent state at various developmental stages and for different durations. These quiescent embryos remain viable even with only sporadic light rainfalls and have been documented surviving for 2–3 years under drought conditions.

The complex physiology of the brown locust egg is essential for survival in the Karoo and plays a key role in outbreaks. The ability of the embryo to enter different states of arrested development enables desiccation-resistant eggs to build up in the soil over time without hatching, allowing hoppers to emerge simultaneously from eggs laid at different times when conditions become favorable. For more in depth information on L. pardalina eggs, diapause, and quiescence see Henschel et al’s 2023 review.

Brown locust nymphs have five instars. Solitarious hopper development lasts about 21–38 days, compared with at least 42 days in gregarious hoppers, which grow larger and give rise to much larger adults; the size contrast between phases is possibly greater in this species than in any other locust. In the field, gregarious females will mature within 2–3 weeks after fledgling and will lay 3–4 egg pods with a mean of 45 eggs at weekly intervals and sources therein. Under experimental conditions a single caged female laid up to 820 eggs in 21 pods, although females in more natural group conditions produced far fewer, averaging a little over two pods each. Egg size ranges from about 5.6 to 7.6 mm in length, with roughly 10–82 eggs per pod and typically 4–5 or more pods per female.

Swarming adults in outbreak areas concentrate at large oviposition sites or “nests,” where millions of locusts may occupy areas of 100 ha or more and dozens of egg pods can occur within a few square decimetres of well‑drained, loose, sparsely vegetated Karoo soil. Under summer conditions adult locusts can live for 2–3 months and live longer during the cooler fall season. Gregarious adults do not survive through the winter.

Habitat and ecology

The brown locust is a ground‑dwelling grass‑feeder whose core range is the semi‑arid Karoo of South Africa and adjacent arid areas of the Free State and Namibia, where sparse, dwarf grass steppe provides both its main food and open patches for basking and oviposition. When populations reach plague levels, swarms can spread over much of southern Africa, even into thornveld, high grasslands, and tree savannah, but these wetter regions generally do not support continuous breeding, so populations either move back to drier areas or die out.

Gregarious hopper bands march in distinctive narrow columns, with 4-5th instar bands covering up to 2-3 km per day ©ARC

Grasshopper activity is limited at ground temperatures below 15°C or above 51°C. Heat-stressed individuals produce stridulatory sounds. In laboratory trials, solitary nymphs preferred temperatures of 35–43°C and low humidity, showing greater tolerance for high temperatures than active transiens hoppers. Solitary grasshoppers begin morning activities by sun-basking, orienting laterally to the sun until ground temperatures reach 35°C, after which they forage until noon. When temperatures exceed 51°C, they move to elevated perches, often in the open but sometimes in shade if available. This behavioral thermoregulation allows them to maintain body temperatures of 39–40°C. Foraging resumes in mid-afternoon as temperatures drop below 39°C, ending in the late afternoon when they dig shallow depressions into the ground to absorb residual warmth overnight. This partial concealment and scattered distribution helps reduce detection by visual predators.

Gregarious hopper behavior follows similar daily thermal patterns. They feed throughout the day with varying intensity depending on collective activity. In the early morning, they bask in the sun, then begin moving in bands. They often rest on elevated plants during the early afternoon, resuming movement as temperatures drop. At dusk, hoppers climb shrubs or tall grass, where they remain overnight.

Large and densely roosting 5th instar gregarious ‘rooibaadjie’ hopper band ©ARC

Eight-day grass (Enneapogon desvauxii) was shown to make up over 84% of the diet for all life stages of solitarious brown locusts in the field, with occasional consumption of other grasses such as Aristida congesta, A. adscensionis, Eragrostis lehmanniana, E. bergiana, Cynodon incompletus, Tragus racemosa, T. koelerioides, and Stipagrostis obtusa, as well as rare nibbling on other plants. Most of these grasses, including S. obtusa, have little value for livestock grazing. Eight-day grass was shown to be the best indigenous Karoo grass for supporting female egg production and rapid nymph development in brown locusts. Gregarious brown locusts are less selective feeders, consuming a broader range of grasses and rarely eating Enneapogon desvauxii, with little interest in shrubs . Laboratory tests showed gregarious locusts have no strong preference among several Karoo grasses. in

Economic losses are greatest in grasses and gramineous crops, including pastures, barley, maize, oats, wheat, sugarcane, and sorghum, especially in sheep‑grazing areas where depletion of grass is most critical. When grass is scarce, L. pardalina may feed on a wide range of other plants and even non-plant materials. Incidental damage has been recorded on cotton, lucerne, potatoes, peas, beans, and various tree crops. Severe damage to citrus has been documented, particularly lemons and, to a lesser extent, navel and Valencia oranges, with thousands of trees damaged on single farms, although non-gramineous crops are generally attacked only when grasses are unavailable. Large numbers of roosting locusts can also break branches, adding to tree damage.

Typical small and medium sized roosting hopper bands in Karoo veld ©ARC

Phase change in the brown locust is density‑dependent. At low densities, hopper movements are limited and largely random, but as densities increase, loose bands coalesce into dense bands that can contain several thousand hoppers per square meter. Multiple consecutive generations of densely banded hoppers are usually required for fully gregarious traits to develop, which helps limit plague formation. Climate, particularly rainfall, strongly influences population trends. Dry early summers may initially suppress numbers but tend to promote higher populations in subsequent seasons, whereas a run of wet early summers generally leads to declines. Adult movements can be substantial, with directionally migrating swarms typically flying downwind at about 25 km/h, sometimes covering up to 150 km in a day. Swarms generally fly by day and roost at night, while indidivua. solitarious adults are more prone to night flight. Gregarious adults disperse downwind from outbreak centers, typically moving east or southeast in swarms steered counter-clockwise by summer high-pressure winds. As the largest swarms travel furthest, portions break off to lay dense egg beds.

Brown locusts experience substantial natural mortality from a wide range of predators and parasites throughout their life cycle. Solitarious populations are particularly affected by vertebrate and invertebrate predators targeting eggs, nymphs, and adults, including birds, small mammals, reptiles, arachnids, and various insects. Desiccation further contributes to high mortality among hoppers and adults in arid habitats. In the gregarious phase, predation pressure shifts notably toward birds, which can suppress hopper bands and even prevent swarm development. Large nomadic species such as pratincoles and storks are especially effective in reducing outbreak intensity. In addition, several parasitoid flies and wasps attack eggs and active stages, sometimes causing marked population declines. Pathogens, notably the protozoan Malameba locustae and the entomopathogenic fungus Entomophthora grylli, occasionally inflict heavy mortality on adult locusts and swarms.​​

Land-use change

Rainfall fluctuations (especially above 150 mm) that increase vegetation cover could lower breeding success as brown locusts prefer bare soil with patchy dwarf grasses for basking and egg-laying.

Historic overgrazing in the Karoo may have degraded land enough to create an ideal habitat for brown locusts. Alternately, brown locusts (and the organochloride pesticides used to control them) greatly impact grazing land, notably in the 1970s when severe damage was done to sheep grazing.

The short- and long-term grazing effects of L. pardalina hopper bands and locust swarms remain critical knowledge gaps, as these unverified impacts are often cited as reasons for the vilification and management of the species. Swarm landing sites could be valuable for research into locust diet, nutrient enrichment from frass, and effects on soil and plant productivity.

Pest status

Roosting adult swarm ©ARC

The brown locust is regarded as one of South Africa’s most serious insect pests. The outbreak area covers approximately 250,000 km² of the semi-arid Nama Karoo biome region of South Africa and southern Namibia out of which plagues have developed span out over 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.

Both hopper bands and flying swarms of the brown locust pose a major economic threat to natural pastures and cereal crops, causing extensive damage to maize, wheat, oats, and sorghum, with some damage also reported to cotton, lucerne, sugarcane, potatoes, peas, beans, and citrus. Early instar hoppers typically feed on grasses near their hatching sites in the Nama-Karoo, while late instar hopper bands can severely damage veld grasses and Karoo bushes, especially when roosting in large groups.

The brown locust has the highest outbreak frequency among African plague locusts, with gregarious outbreaks requiring chemical control occurring in the Nama-Karoo in about nine out of every ten years. Some years see only a few small hopper bands controlled, but during major outbreaks, such as 1985–1986, over 250,000 hopper bands and 40,000 adult swarms were managed in South Africa. Major plagues typically happen once per decade and often spread to neighboring countries like Namibia, Botswana, and Lesotho. The brown locust is officially registered as a national pest in both South Africa and Namibia.

Management

Brown locust (Locustana pardalina) outbreak. Photo by Free State Department of Agriculture

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, the semi-desert regain of South Africa, to manage the brown locust for example, and streamlining communication between farmers, land managers, and government officials remains difficult.

Responsive, preventive control is thought to be crucial to prevent gregarious brown locust outbreaks from escalating into large-scale plagues, as managing thousands of marching hopper bands and flying swarms becomes nearly impossible once an outbreak is underway. Because swarms develop only within South Africa, the government established a dedicated section under the Chief Locust Officer to coordinate control efforts. Farmers are legally required to destroy any hoppers found on their property, while the government is responsible for eliminating hopper bands and adult swarms. Early warning systems require landowners to report outbreaks, and appointed Locust Officers scout, report, and control locusts, with all sightings relayed to regional control depots. Field monitoring is conducted by local farmers in their districts.

Brown locust damage to maize field. © K Viljoen, DAFF-LUSM, 2006

Chemical control relies on vehicle-mounted or knapsack sprayers with registered pesticides, applied mainly at dawn or dusk when grasshoppers are aggregated and roosting. Aircraft control is reserved for plague conditions, with synthetic pyrethroids like esfenvalerate and deltamethrin currently used. Metarhizium acridum (Green Muscle®) can be used in South Africa, formulated as an oil-based mycoinsecticide for ultra-low volume spraying, but it is not widely adopted operationally due to the need for rapid knockdown.

Although the potential for crop damage by brown locusts is often highlighted in the media and non-scientific sources, there is no documented, quantitative evidence of large-scale crop devastation by brown locusts that would constitute a national disaster in South Africa. This may be attributed to effective preventative control measures. However, formal risk assessments of potential crop losses or cost-benefit analyses to justify the ongoing costs of control campaigns versus the loss of ecosystem services have not been conducted.

Outbreaks

Fig. 5 from Henschel et al 2023 Annual records of brown locust (Locustana pardalina) outbreaks in southern Africa since 1797

Records of brown locust outbreaks in the Karoo have been kept for over 200 years. Years with exceptionally high brown locust activity were 1985–86, 1950–51, 1970–71, 1963–64, and 1971–72. The last major plague of L. pardalina happened in 1985–97 and cost an equivalent to $25 million USD. An outbreak in 1995-96 cost $3.5 million US.

For a comprehensive analysis of historical outbreaks of the brown locust in South Africa's Nama Karoo from 1960 to 2005, and extending earlier records back to 1796 view this document Analysis of historical outbreaks of the brown locust.

• 
  Analysis of historical outbreaks of the brown locust

2021-2022 outbreak

Above-average rainfall across many parts of Southern Africa in 2020 allowed populations of L. pardalina to skyrocket. Initial outbreaks started in 2020 in the eastern and south-eastern of the usually arid Karoo. This current outbreak primarily impacted South Africa and Namibia, with some 2021 reports in Botswana and Angola. 80 million rand (5.4 million USD) was spent on control operations with a heavy reliance on broad-spectrum pyrethroid insecticides. Although there were 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. According to The Namibian, in 10 of South Africa's 14 regions, the locusts destroyed over 719,000 hectares of grazing land and 1,207 hectares of crop fields, with the Kharas region being the worst affected.

Associated organizations

Insight into management flow from Government of South Africa press release 3/17/22 via All Africa "Our immediate step is to mitigate the locust infestation in the Western Cape in collaboration with its sector partners such as organised agriculture, DALRRD, district municipalities, District Locust Officers, and Provincial Disaster Management Centre (PDMC). The PDMC has activated the Locust Joint Operation Committee (JOC), and a 24-hour action plan has been put in place until the locust infestation levels are under control."

Organization name	Acronym	Website	Type	Focus	Focus keywords	Geographic purview
Agri Northern Cape		View	Government	Management, Governance	Coordination	South Africa
Agri SA		View	Government	Management	Control, Forecasting, Monitoring	South Africa
Ministry of Agriculture, Water and Land Reform	MAWLR	View	Government	Management	Monitoring	Namibia

Resources

Title	Author(s)	Year	Geographic purview	URL
ARC-PHP brown locust fact sheet series	Agricultural Research Council of South Africa,Roger Price	2024		View URL
Analysis of historical outbreaks of the brown locust	Agricultural Research Council of South Africa,Roger Price	2026		View URL
FAO locust handbook identification key	FAO Desert Locust Information Service and Food and Agriculture Organization of the United Nations			View URL
2021 evaluation of field trials data on the efficacy and selectivity of insecticides on locusts and grasshoppers	Locust Pesticide Referee Group and Food and Agriculture Organization of the United Nations	2021		View URL
CABI Green Muscle education videos	Centre for Agriculture and Bioscience International	2021
Agricultural marketing advisory note: brown locust outbreak in South Africa	National Agricultural Marketing Council	2020		View URL
USAID Transboundary Outbreak Pest ETOP bulletins	United States Agency for International Development

Featured resources

• 
  Analysis of historical outbreaks of the brown locust
• 
  ARC-PHP Locust fact-sheet series

Specimen contributors for this species

Natural history collections are built by people. The specimens that document this species were collected in the field, preserved in collections, and identified by generations of researchers and naturalists. Bionomia helps make these often-overlooked contributions visible by linking specimen records to the people behind them.

The contributors shown here are drawn from specimen records made available through GBIF and attributed to individuals by Bionomia. Each list shows up to the 20 people with the most specimens for this species, ranked from most to fewest.

Collected by

These people collected specimens of this species in the field, helping build the physical record of where and when it has occurred.

• 0000-0002-5087-262X — 7 specimens collected
• Cathy Dzerefos — 4 specimens collected
• Ruan Booysen — 4 specimens collected

• Craig Peter — 2 specimens collected

Identified by

These people examined specimens and determined their taxonomic identity—an essential step in turning a collected specimen into a useful biodiversity record.

• Cathy Dzerefos — 4 specimens identified
• Ruan Booysen — 3 specimens identified
• Craig Peter — 2 specimens identified

• 0000-0002-5087-262X — 1 specimen identified

Bionomia has no page for individual species, but the family-level view lists everyone credited across the whole group: See all Acrididae specimen contributors on Bionomia.