Impact of the Locust Outbreak in West Africa

Assessment of the risks that the ongoing locust outbreak poses to acute food insecurity in West Africa, with a particular focus on Mauritania, where the outbreak is currently concentrated.

Current situation

As of December 2025, desert locust activity in West Africa is worsening in the Islamic Republic of Mauritania and Western Sahara, with Mauritania representing the primary hotspot. Immature adult groups and small swarms have been detected across several areas of the country, prompting expanded national and regional monitoring. Historically, locust outbreaks in West Africa, including the 2003-2005 regional event that met the definition of a plague, have frequently impacted Mauritania. The country is heavily reliant on recession agriculture along the Senegal River, where the cropping calendar coincides with winter and spring locust breeding and migration cycles, increasing locust exposure during key cultivation periods. 

While the FAO Locust Watch indicates that adult groups and small swarms may appear in other countries including Mali, Niger, Chad, Algeria, and Morocco, sightings outside of Mauritania remain limited. Isolated or scattered adults and some small groups/hoppers have been reported in localized areas of Chad (Barh-El-Gazel and Ennedi Ouest regions) and southeast Niger (in the Termit Massif region).

At this time of year, the desert locust migration typically moves northward toward winter and spring breeding areas in the Maghreb. Large-scale control operations in Algeria, Libya, Morocco and Tunisia in December are intended to reduce the likelihood of further spread. However, whether the outbreak extends into other areas of West Africa will depend on wind patterns, vegetation availability, and the effectiveness of ongoing control operations.

Expected impact on crops and pasture

The immediate risk of negative impacts on agriculture in West Africa is currently low through May 2026. The main rainfed harvest is nearly complete across the central Sahel, leaving minimal standing crops. While Mauritania received above-average rainfall in November-December, the rainy season ended in the central Sahel 2-3 months ago. The drying out of rangeland creates less conducive conditions for locusts. Additionally, locust migration patterns through the spring typically favor northward movement into North Africa, including Morocco and Algeria.

The primary area of residual concern is northern Senegal, particularly the Senegal River Valley, which borders the affected areas of Mauritania. There is a low-probability risk of locust incursions should control operations in Mauritania weaken or vegetation remain unusually favorable.

Vulnerability of poor households to locust outbreak

Across West Africa, poor rural households are heavily dependent on their own production for food and income, but they typically cultivate small plots and have limited access to inputs, irrigation, and pest control measures. They typically have fewer buffers to shocks, with minimal livestock and limited savings; seasonal labor and petty trade are not expandable enough to fully compensate for production losses. As a result, shocks to crops or pasture typically have a direct impact on food security. At this time of year, however, the peak periods for crop and livestock production have already concluded, meaning household vulnerability to harvest and pasture losses is lower.

In the most likely scenario, however, the locust outbreak is expected to remain concentrated in Mauritania and the Western Sahara, with threats posed to North Africa during the winter and spring northward migration. Broader impacts in West Africa are likely to be limited in the medium-term.

In the less likely event of a southward or eastward migration of locusts into West Africa, vulnerability would be highest among those who depend on off-season agriculture, including flood recession and irrigated systems. Poor pastoral households in northern Mali and Niger would also be vulnerable if already limited dry-season pastures were further compromised.

Likely acute food insecurity impacts

Overall, West Africa faces a low risk of worsening acute food insecurity due to a locust outbreak in the medium term. Given the end of the main rainy season, northward migration patterns of locusts, and ongoing control measures, the likelihood of locust expansion in West Africa remains low. Seasonally dry conditions across the Sahel are not conducive to significant breeding, reducing the probability of widespread crop or pasture losses.

It is possible that forecasted above-average, off-season rainfall in parts of the northern Sahel during the winter and spring could create localized conditions favorable for small-scale breeding, particularly in northeastern Mali and northwestern Niger. If this occurs, control operations may be required to prevent the formation of additional groups, and livestock in these areas would be vulnerable to further reductions in seasonally low pasture availability. However, main season harvests have already concluded and the risk of acute food insecurity due to a locust shock is lower at this time of year. As a result, desert locusts pose a low risk to food security on the regional scale.

Still, poor households in affected localized areas would likely be at risk of deepening food insecurity. Large-scale food security impacts from desert locusts do not typically happen in isolation, but in interaction with other weather, macroeconomic, or conflict-related shocks. The region is already experiencing acute food insecurity due to conflict, poor macro-economic conditions, and the localized weather shocks that occurred during the 2025 production season. Conflict-affected populations in Mali, Burkina Faso, Niger, and Chad have already experienced displacement, loss of assets, and limited access to land and grazing resources. As such, they have reduced capacity to cope with even small-scale locust incursions if they affect dry-season grazing or small-scale off-season cultivation.

Current situation

As of December, Mauritania has been experiencing an ongoing resurgence of desert locusts, with the most significant concentrations observed in Trarza, Inchiri, and Adrar regions and the Aguilal Fay depression/lowlands. The Commission for the Control of Desert Locusts in the Western Region (CLCPRO) expert mission, which conducted an assessment from October 12 to 19, 2025, confirmed that favorable breeding conditions exist following above-average rainfall since September. Locusts are present in various development stages, and there is a risk of rapid locust population growth in the absence of effective control measures. With continued rainfall expected in December, a third generation of breeding is likely to begin across a wide western belt of the country. Although forecasted low temperatures may slow development rates, immature adult groups are expected to mature and lay eggs, with peak activity anticipated in the second half of December and new hopper bands likely to emerge in January.

The National Center for Locust Control (CNLA) reports that mitigation operations have been intensified and that the situation is currently under control. Treatment has covered 21,218 hectares (ha) as of December 5, with a goal of treating 50,000-100,000 ha through January. However, officials stress the need to maintain close vigilance and continuous monitoring through January, given renewed breeding opportunities created by the recent above-average rainfall.

Expected impact on crops and pasture

Mauritania’s agricultural land is estimated at 502,000 ha, largely concentrated in the south. Agricultural production is dominated by flood recession agriculture along the Senegal River and in lowland areas and by irrigated rice cultivation, accounting for roughly 85 percent of national cereal output. Rainfed rice accounts for the remaining bulk of production. The main cereal harvest and flood recession planting runs from October to mid-December, and the flood recession and off-season harvests occur between January and May.

Locust impacts on irrigated and flood recession off-season crops are expected to be localized but substantial. While a portion of crops have already been harvested, irrigated and flood recession agriculture are critical to production totals. Preliminary estimates for the 2025/2026 cereal production year were made prior to the peak of the locust outbreak, and therefore do not capture the likely scale of production losses. Initially, the main harvest was projected to reach 734,903 metric tons, a 38 percent increase from the five-year average. However, harvests are ongoing in key rice production areas like the Senegal River Valley and Trarza Region. Trarza Region is among the most directly affected areas; current estimates suggest that production losses remain below 20 percent compared to average. Nonetheless, main-season rice that has not yet been harvested and off-season rice are exposed to additional losses.

Pastoral resources are also at risk. In the pastoral Inchiri and Dakhlet Nouadhibou regions, locusts have already damaged tree-covered pastures, which are the only year-round available pastoral resource in the area. This poses a direct threat to camel, goat, and sheep production. Furthermore, the destruction of pastures in the Senegal River basin increases strain on herders who already face restricted mobility due to the continued closure of the border with Mali.

Vulnerability of poor households to locust outbreak

Over 62 percent of the population depends on agricultural production for their livelihoods, with livestock-raising as the main rural livelihood in Mauritania. A smaller proportion of poor households that are engaged in recession agriculture, irrigated rice cultivation, and dry-season lowland farming are among the most exposed to crop and income losses due to the locust outbreak. Households dependent on date production in the oasis zones, which are harvested between June and August, also face increased risk if the locust outbreak and associated vegetation loss moves northward.

Pastoralists are also vulnerable to the locust outbreak given their dependence on scarce and seasonally variable grazing resources. The loss of key grazing areas may prompt atypical livestock movements, potentially toward Senegal, The Gambia, or coastal zones, increasing the risk of livestock disease, conflict, and distress sales. Restrictions on movement toward Mali, typically an important grazing corridor, further limit coping options and may accelerate localized pasture exhaustion on the Mauritanian side of the border.

Acute food insecurity impacts

Overall, the risk of acute food insecurity in Mauritania is currently considered moderate. Concern is highest for areas in the southwest, where the locust outbreak is concentrated and where recession and irrigated crops are central to poor households’ food and income sources. The area of greatest concern is Trarza. More severe impacts are expected to be mitigated by control measures and the low likelihood of eastward migration into other key production areas of Mauritania, given typical northward seasonal migration patterns.

Local market conditions are already fragile due to price volatility and disruptions to regional trade flows, particularly reduced cross-border flows from Mali. In the short term, localized price spikes for cereals are likely in the areas worst affected by the outbreak, driven by reduced local availability and disrupted supply chains. For poor farmers, reduced production and higher prices may constrain food access as the post-harvest period advances.

Additionally, in the pastoral zones of Inchiri and Dakhlet Nouadhibou regions, ongoing destruction of tree-covered pastures may further weaken livestock body conditions and lead to distress sales of livestock in areas experiencing pasture loss. These factors will likely temporarily depress local animal sale prices and weaken the livestock-to-cereal terms of trade for pastoral households, reducing their ability to purchase food.

However, given the continued favorable breeding conditions of locusts, there is a credible risk of an alternative scenario in which acute food insecurity impacts would deepen or become more widespread. Specifically, this scenario could materialize if planned control operations do not proceed, or if wind patterns and favorable vegetation attract locusts to the southeast.