Locust Swarms Ravaging East Africa Are the Size of Cities

A devastating pest outbreak is threatening millions of people with hunger.

Mary Muthoni runs through her farm in Mathyakani, in southeast Kenya, shaking a bottle filled with pebbles at the clouds of locusts that swarmed into her village the night before. That morning, the whole community rose early to try chasing off the insects, banging on pots and pans, blowing whistles and honking motorcycle horns.

“We first woke up and prayed. We prayed that the Lord shut the mouths of the locusts,” Muthoni said.

It’s a scene that’s playing out across East Africa as swarms of desert locusts spread through the region, destroying crops and pastures at a voracious pace. The United Nations has warned of an unprecedented threat to food security in a part of the world where millions already face hunger. And the situation will probably get worse before it gets better.

Experts say the outbreak—the worst in recent memory—is caused by an increased number of cyclones. If the weather trends continue, there may be more to come.

“There is a link between climate change and the unprecedented locust crisis plaguing Ethiopia and East Africa,” UN Secretary General Antonio Guterres said. “Warmer seas mean more cyclones generating the perfect breeding ground for locusts. Today the swarms are as big as major cities and it is getting worse by the day.”

▲ A farmer tries to drive desert locusts from a farm in Mwingi, Kitui County, Kenya.
▲ Women in Mathyakani village, Kitui County, Kenya shake bottles filled with pebbles to scare the insects away from their farm.
▲ A swarm of desert locusts in a tree. The insects are so densely clustered that from far away the foliage takes on a brown hue.

The number of locusts in East Africa could expand 500 times by June, the UN's Food & Agriculture Organization said last month. The region gets heavy seasonal rains—and great locust-breeding and swarming conditions—from March through May. Last year, the October-to-December rainy season was among the wettest in 40 years, with cumulative rainfall ranging from 120% to 400% of normal.

“Locust outbreaks are expected to become more frequent and severe under climate change,” said Rick Overson, a research coordinator at the Global Locust Initiative at Arizona State University. “Locusts are quite adept at responding rapidly and capitalizing on extreme rainfall events.”

It’s a daunting prospect for a region and continent where food security is already precarious. African farmers have struggled in recent years with destructive pest attacks including the fall armyworm and tomato-leaf miner. Insect dynamics have also shifted with climate change, according to Baldwyn Torto, principal scientist at the International Centre of Insect Physiology and Ecology.

The desert locust may be the most dangerous yet.

“Just a single locust swarm, if it comes into a farmer’s field in the morning, by midday it has eaten the entire field,” said FAO locust forecasting expert Keith Cressman. “That one field represents the entire livelihood of that farmer.”

The current outbreak started in the areas around the Red Sea, a key winter breeding area for desert locusts, and spread through the Horn of Africa and into East Africa. As locusts devour crops in Ethiopia, Kenya and Somalia, the insects are breeding in Djibouti, Eritrea and Sudan—all areas that are prone to drought and food shortages. Swarms have arrived in Uganda, and locusts have also crossed into Tanzania. A mature swarm entered South Sudan on Monday, the FAO said.

Spreading Fast

Desert locust swarms are threatening food security

Source: FAO Locust, February 2020

The outbreak was fostered by a long dry spell followed by sudden high rainfall, said Torto.

“The current rainfall and vegetation index have been unusual, all the right recipe to provide the moisture conditions for locust eggs buried in the soil for decades to mass hatch into hoppers to feed and rapidly develop on the lush vegetation,” he said.

The locust invasion could lead to a considerable drop in agricultural production and exacerbate malnutrition and hunger. In Djibouti, Eritrea, Ethiopia, Kenya and Somalia, more than 13 million people are experiencing severe acute food insecurity, according to the FAO. Another 20 million are on the verge of falling into crisis if their crops are damaged or they lose their livestock.

▲ Locusts swarm in Mwingi, Kitui County, Kenya.

Locusts are part of a group of insects commonly called grasshoppers, but have the ability to change their behavior and can migrate over large distances. Desert locusts can have about 40 million to 80 million locust adults in each square kilometer of a swarm and travel up to 150 kilometers a day, according to the FAO.

There is an exponential increase in locust numbers with every new generation of breeding and a swarm the size of one square kilometer, containing about 40 million locusts, eats the same amount of food in one day as about 35,000 people.

Corn plants damaged by the swarms
▲ Corn plants damaged by the swarms.

The locust infestation is the worst in Kenya in 70 years, according to the FAO. In Ethiopia and Somalia, it’s been 25 years since an outbreak of this severity.

Desert locusts will eat most plants they find and can destroy 80% to 100% of crops in areas where they invade, said Overson.

“This damage has the most impact on food security in areas with high numbers of subsistence farmers,” he said.

To control the outbreak, the FAO is working with governments and other groups to spray swarms with pesticides. The FAO asked for $76 million to control the locusts’ spread, but had only received about $20 million by Feb. 10.

“We need to act quickly,” said UN Under Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator Mark Lowcock. “We do have a chance to nip this problem in the bud, but that’s not what we’re doing at the moment. We’re running out of time.”

Containing the Swarms

Size of area treated in affected African countries

Source: FAO Locust Bulletin

The task is more difficult because of political instability in some countries. In Somalia, for example, the FAO says that aerial spraying has been ruled out in areas not controlled by the government. The civil war in Yemen may also have contributed to the outbreak.

“Politics, climate and biology coinciding has allowed the formation of bigger swarms,” said Bill Hansson, a professor at the Max Planck Institute of Chemical Ecology in Jena, Germany.

There’s also concern that the efforts to control the outbreak may have unintended consequences.

“We should be careful with spraying because it may kill other insects which are very useful in the ecosystem, such as bees for pollination,” Hansson said.

The locust threat isn’t limited to East Africa. Swarms in Pakistan have damaged crops including wheat and cotton and the country declared a national emergency to combat the locust attack on Jan. 31. The insects have crossed over to India and damaged crops in the northwest states that border Pakistan. Somalia has also declared an emergency.

While there are systems in place to try to predict locust outbreaks, many governments are not prepared to deal with them because of a lack of resources, said the ICIPE’s Torto. Africa is also particularly vulnerable to the effects of climate change on pest populations, he said.

▲ Locusts ravage a farm in Mathyakani village, Kitui, Kenya.

“Farmers’ traditional coping methods are ineffective,” he said. “They have resorted to indiscriminate spraying of pesticides to address the problem, creating more problems.”

In Ethiopia, people are burning tires and trash, hoping the smoke will drive the locusts away. Farmers in traditional white scarves whistle and shout at the pests, while cars in urban areas honk at the swarms as the government intensifies aerial control.

Back in southeast Kenya, 45-year-old Esther Kyalo’s crop of cowpeas was ravaged by locusts after the swarm arrived in late January. This was her second planting after bad weather destroyed the first harvest.

“We planted in April but it all dried up,” said the mother of two. “We may be staring at hunger now.”

—With assistance from Agnieszka de Sousa, Felix Njini, Swansy Afonso and Samuel Dodge

(Corrects to add missing word to a quote by FAO locust forecasting expert Keith Cressman. He said it was a single locust swarm, not a single locust. A previous version of this story was updated to include a swarm entering South Sudan. )