Red locust (Nomadacris septemfasciata)

Nomadacris septemfasciata
Photo by Michel Lecoq
Other common names
Nzige mwekundu (Sw), Gafanhoto vermelho (Pt), Criquet nomade (Fr), Rooi sprinkaan (Af), Valala mena elatra (Mg)
Taxonomic classification
Suborder:	Caelifera
Family:	Acrididae
Subfamily:	Cyrtacanthacridinae
Tribe:	Cyrtacanthacridini
Genus:	Nomadacris
Scientific name
Nomadacris septemfasciata (Serville, 1838)
Geography
Native countries:
Mauritania Kenya Angola Botswana Lesotho Madagascar Malawi Saint Helena, Ascension and Tristan da Cunha Réunion Mauritius Mozambique Namibia Sudan Nigeria Tanzania Zambia Zimbabwe
Pest status
Known pest

The red locust (Nomadacris septemfasciata) is found in sub-Saharan Africa. Today its outbreaks are frequent but mostly limited to specific grasslands and seasonal floodplains located in Malawi, Mozambique, Tanzania, Zambia, and to a lesser extent in southern Madagascar. Important breeding areas are the central Niger delta in Mali and the southern shores of Lake Chad.

Taxonomy

For full nomenclature and taxonomic details of this taxon, see Orthoptera Species File

Identification

The red locust (Nomadacris septemfasciata) 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 Central American locust (S. piceifrons), the South American locust (S. cancellata), the Bombay locust (Patanga succincta), the Sahelian tree locust (Anacridium melanorhodon), the brown locust (Locustana pardalina), 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.

Morphologically, Cyrtacanthacridinae species are distinguished by the presence of a prosternal spine (a pointed projection between the forelegs) 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

N. septemfasciata is a large, mostly brown locust that becomes darker and redder with age. The tegmina bear seven oblique dark bands, and the hindwings develop a rose-colored tint at the base. A medium ochraceous band extends from the vertex across the head and pronotum, continuing along the costal area of the folded tegmina. Another band appears laterally on the pronotum and runs along the hind margin of the tegmina. The lowest pale band lies on the lower edge of the pronotum, remaining parallel-sided.

The number of eye stripes in N. septemfasciata may indicate its phase: swarming locusts predominantly have seven stripes, solitary ones have eight, and when over 50% of a solitary population shows seven stripes, it signals the population is shifting toward the gregarious phase. in

N. septemfasciata is easily mistaken for species of Ornithacris, which share similar wing coloration but differ in overall pigmentation.

Identification graphic courtesy of the IRLCO-CSA

Identification resources

Title	Author(s)	Year	Geographic purview	URL
Michel Lecoq entomology website	Michel Lecoq	2014		View URL
FAO locust handbook identification key	FAO Desert Locust Information Service and Food and Agriculture Organization of the United Nations			View URL
CIRAD pest locust website	The French Agricultural Research Centre for International Development			View URL

Distribution

Small, non-swarming populations of N. septemfasciata occur in grasslands across much of sub-Saharan Africa. This species is also found on several Indian Ocean islands, including Madagascar, Mauritius, Réunion, and the Comoros. Isolated populations also occur in the Lake Chad Basin, the central Niger River delta in Mali, and the Cape Verde Islands.

For more information and distribution records see [GBIF]

Nomadacris septemfasciata in solitary phase taken in Madagascar in 2007 by Michel Lecoq.

Biology

The red locust undergoes phase transformation, with gregarization triggered at densities around 5,000 adults/m². At high densities, this species forms hopper bands and adult swarms. Hopper bands move in rolling waves, with feeding individuals replaced at the front by those that have finished feeding. In dense vegetation they move little, but in open areas can advance up to 700 m/day. Adults emerging from bands remain cohesive, forming low-flying swarms that typically travel short distances.

Red locusts are univoltine, with adults entering dry-season diapause. South of the equator, mating and egg-laying occur at the start of the rainy season (November–April), with eggs incubating 24–36 days and hoppers developing in 50–70 days. Adults emerge in March–April, harden, and remain in reproductive diapause until the first rains. Solitary populations migrate at night, while swarms move 20–30 km per day and roost in trees. North of the equator, reproduction is timed to seasonal rains (April–August), and in equatorial regions without a marked dry season, breeding is year-round but adults remain immature for six months. In equatorial areas like southwest Uganda, breeding can occur year-round, but the long immature phase keeps the cycle univoltine.

Red locusts in Madagascar undergo full phase transformation (solitarious, transiens, gregarious) at densities of only 10/m², contradicting long-held assumptions that only solitarious/transiens forms existed there. Pigmentation reliably tracks density, confirming gregarization thresholds and showing that both parental history and mechanical, visual, and olfactory stimuli drive the process.

Habitat and ecology

The red locust mainly inhabits tall, dense grasslands, feeding primarily on grasses and using bushes and trees as perches. Key outbreak areas include floodplains and marshes in Tanzania (Rukwa Valley, Malagarasi and Wembere plains), Zambia (Kafue marshes and Mweru-wa-Ntipa Valley), Malawi (Lake Chilwa), Mozambique (Busi-Gorongosa flood plains), Mali, and the Chad Basin, where resident populations can produce swarms. These areas provide ideal breeding habitats with tall and short grasses.

Red locust outbreaks typically occur in ecologically sensitive habitats such as wetlands, treeless grasslands with poor drainage, and seasonally flooded plains and valleys, including some protected areas. Escaping swarms can threaten subsistence farming in nearby districts and, during major upsurges, may travel long distances across international borders. In addition to traditional outbreak zones in mainland Africa, outbreaks have also occurred in southwestern Madagascar, where swarms can cause significant local damage. By contrast, areas such as the central Niger Delta in Mali and the Chad Basin support bands and swarms but have never experienced full plagues.

Although all red locust outbreak areas have been identified, the intensity of outbreaks varies over time. By 1999, the main areas requiring close monitoring included the Wembere and Iku-Katavi plains, Malagarasi basin, Kafue Flats, Chilwa plains, and Buzi-Gorongosa plains. Other traditional areas, such as the Rukwa Valley and Mweru wa Ntipa, have remained largely inactive since the 1960s. Non-traditional zones have occasionally supported substantial breeding and swarming, prompting IRLCO-CSA control measures. These include the Chobe plains in Botswana and the adjacent Kaprivi Strip in Namibia, the Lukanga swamps in Zambia, Bahi Valley in Tanzania, and Lake Chiuta plains in Malawi, which share ecological characteristics with established outbreak areas.

In Madagascar, N. septemfasciata is a persistent crop threat. They migrate seasonally between breeding and refuge zones, with movements shaped by rainfall and wind. Breeding success hinges on rainfall patterns, and while clustering in favorable areas can trigger gregarization, their univoltine cycle and higher outbreak threshold help explain why red locust outbreaks are rarer and smaller than those of migratory locusts.

Land-use change

With growing human populations, traditional Red Locust outbreak zones are no longer remote or uninhabited; farmland and settlements are steadily expanding into these areas. Many outbreak zones overlap with game reserves and national parks, meaning major ecosystem alterations to suppress locusts would threaten wildlife populations and harm national economies.

Red locusts frequently damage crops in Madagascar, a problem that has intensified in recent years, likely due to ongoing deforestation. in

Management

The main strategy for red locust control is to prevent swarms from escaping breeding areas. Efforts target both hopper bands and the breeding potential of adults. Containment is critical, as outbreak zones make up less than 0.1% of the locust’s 8 million km² invasion area.

International control began in 1941 in Tanzania and Zambia and is now managed by the International Red Locust Control Organization for Central and Southern Africa (IRLCO-CSA). IRLCO-CSA is an intergovernmental body that succeeded the International Red Locust Control Service (IRLCS), founded in 1949 after 15 years of research into the plague of N. septemfasciata that lasted from 1929 to 1944. IRLCS aimed to prevent future plagues by identifying their sources and targeting hopper bands and early swarms in outbreak areas. In 1970, it was replaced by IRLCO-CSA under a new convention, with similar goals but an expanded mandate to also monitor and forecast other migratory pests, including the African Armyworm (Spodoptera exempta) and Red-billed Quelea (Quelea quelea). Member states include Kenya, Malawi, Mozambique, Swaziland, Tanzania, Uganda, Zambia, and Zimbabwe.

IRLCO-CSA conducts regular monitoring and targeted interventions, preventing major outbreaks for the past four decades. Monitoring is based on population density and rainfall patterns, with helicopter surveys timed to the wet and dry seasons. The IRLCO-CSA is funded by member-state contributions, often supplemented by donors such as the UK, Germany, Switzerland, FAO, UNDP, and the African Development Bank. While most members have remained committed, some countries never joined or withdrew, and owe money persist due to economic constraints. A 1997 FAO-supported restructuring streamlined operations, rationalized contributions, and set a US$1 million budget. Despite its success in preventing plagues, complacency among decision-makers poses a continuing risk to adequate funding.

In Madagascar, management is coordinated by the National Anti-Locust Centre as part of broader crop protection programs.

Biopesticides using the fungus Metarhizium acridum have proven effective and environmentally safe, achieving up to 80% mortality in one to three weeks, particularly in nymphs and immature adults. Although slower than chemicals, they are host-specific and suitable for use in sensitive habitats as much of the red locust outbreak area are wetlands with a rich flora and fauna. Ecological approaches such as grazing to change grassland composition or tree planting have generally failed, and traditional methods like trapping or burning hoppers are largely ineffective. Chemical control therefore remains the most widely used method, relying on ultra-low volume aerial spraying of hopper bands and adults. Helicopter and fixed-wing operations using organophosphate pesticides are most effective, with treatment thresholds set at more than ten adults per square meter.

Natural enemies significantly affect red locusts but are generally secondary to climatic factors and high first-instar mortality. Eggs are eaten by flies, beetle and wasp larvae, rodents, and mites, though desiccation and flooding are often more critical. Hoppers are mainly killed by the fungus Entomophthora grylli, with insects, nematodes, and occasional birds adding minor effects. Adults are also susceptible to E. grylli, Metarhizium anisopliae, and other pathogens, though predators have limited impact overall. Introduced species like the Indian mynah (Acridotheres tristis) in Mauritius can effectively suppress populations, and in some regions birds are legally protected as locust predators.

Pest status

The red locust is of major economic importance because of its impact on crops and pastures. Both nymphs and adults feed on a wide variety of plants, though they show a marked preference for grasses, particularly soft, moisture-rich species, while crops such as cereals and sugar cane are especially vulnerable. More than 50 crop species may be affected, including cotton, citrus, tobacco, legumes, and vegetables, have also suffered damage, while a few plants like coffee, mango, and tea appear largely unaffected. Grazing lands for sheep and cattle are also damaged, sometimes worsening livestock conditions, and heavy swarms can even break tree branches. Over the past 130 years, three major plagues have occurred alongside frequent smaller outbreaks.

Outbreaks

Three major plagues of the red locusts have occurred over the past 130 years (1847–1854, 1891–1920, 1930–1944), together lasting over 50 years and punctuated by regular outbreaks.

The last major red locust plague (1929–1944) affected most African countries south of the equator. It spread from the Mweru wa Ntipa marshes and Rukwa Valley across much of southern and eastern Africa, peaking in 1934 when swarms covered over 7 million km². Key breeding areas in Malawi, Zimbabwe, the Zambezi Valley, Uganda, and Tanzania enabled the plague to persist until 1944. Although crop losses were poorly quantified, South Africa recorded £20,000 in damages compared to £933,000 spent on control, highlighting the high economic burden.

Red locust damage in Mozambique, Zimbabwe, Madagascar, Mauritius, and the Comoros, merited prevention assistance from international control organizations, spending £80,000–£240,000 annually from the 1950s to 1970s.

Widespread upsurges occurred from the 1980s through the 1990s, with notable outbreaks reported between 1985 and 1997. Several outbreaks from 1994 to 1996 coincided with migratory locust plagues that took place between 1996 and 2000. Overall, the period from 1981 onward was the most active since the plague suppression campaigns of the 1940s.

In the 1996 outbreak, numerous red locust swarms emerged in Mozambique’s Buzi-Gorongosa outbreak zone. Some of these swarms crossed into neighboring countries—Zimbabwe, Zambia, Botswana, and South Africa—on a scale not seen since the 1929–1944 plague. While no breeding occurred in the invaded countries, swarms that reached Malawi reproduced successfully, producing hopper bands. These filial generation outbreaks persisted into 1997 in the original breeding area, though at a smaller scale.

In 2009, FAO announced that an international campaign successfully contained a major red locust outbreak in Eastern and Southern Africa, protecting crops for 15 million people. Coordinated with IRLCO-CSA, the effort used biopesticides and conventional pesticides in Tanzania, Malawi, Mozambique, and Zambia.

Associated organizations

Organization name	Acronym	Website	Type	Focus	Focus keywords	Geographic purview
International Red Locust Control Organization for Central and Southern Africa	IRLCO CSA	[www.redlocust.org.zm/ View]	Intergovernmental Organization	Management, Governance, Funding	Monitoring, Control, Regional cooperation, Forecasting, Natural sciences	Zambia, Zimbabwe, Mozambique, Kenya, Tanzania, Malawi
Ministry of Agriculture, Water and Land Reform	MAWLR	View	Government	Management	Monitoring	Namibia

Resources

For more papers on the red locust, see Bahana 1999 for a compilation of abstracts of 91 published articles on the red locust, Nomadacris septemfasciata (Serville) for the period 1940-1998.

Title	Author(s)	Year	Geographic purview	URL
Rearing and Breeding Locusts in the Laboratory	Anti-Locust Research Centre,Philip Hunter-Jones	1966		View URL
Michel Lecoq entomology website	Michel Lecoq	2014		View URL
Supplementary environmental assessment (SEA) for USAID funding of locust or grasshopper pesticide usage in Sudan	United States Agency for International Development	1990		View URL
Locusts have caused problems for quite some time	Commission for Controlling the Desert Locust in the Central Region and Food and Agriculture Organization of the United Nations			View URL
2014 evaluation of field trials data on the efficacy and selectivity of insecticides on locusts and grasshoppers	Commission for Controlling the Desert Locust in the Central Region and Food and Agriculture Organization of the United Nations	2014		View URL
FAO locust handbook identification key	FAO Desert Locust Information Service and Food and Agriculture Organization of the United Nations			View URL
CABI Green Muscle education videos	Centre for Agriculture and Bioscience International	2021
CIRAD pest locust website	The French Agricultural Research Centre for International Development			View URL
Locust Literature	The French Agricultural Research Centre for International Development			View URL
USAID Transboundary Outbreak Pest ETOP bulletins	United States Agency for International Development

Specimen contributors for this species

Bionomia links specimen records in GBIF to the people who collected and identified them. Each list shows the top 20 for this species. Read more…

Collected by

People who collected specimens of this species in the field.

• Angelo Andrianiaina — 12 specimens collected
• William Stephens — 1 specimen collected
• Luis Pascoal da Silva — 1 specimen collected

Identified by

People who determined the taxonomic identity of specimens of this species.

• Angelo Andrianiaina — 9 specimens identified
• William Stephens — 1 specimen identified
• Josip Skejo — 1 specimen identified