2020’s Plague of Locusts Spreads to Indian Subcontinent and South America

By Lambert Strether of Corrente.

I thought I’d lighten up the mood by posting on a plague that’s actually visible: locusts (here is a photo essay in The Atlantic. See also previous NC posts in February and March. Wikipedia has a country round-up). Since the locust swarms of East Africa are already well-covered (“Crunch, crunch: Africa’s locust outbreak is far from over“), I’ll look at the Indian subcontinent (Nepal, Pakistan, India) and Latin America (Argentina, Brazil). To review, locusts are bad. From NPR, “Locusts Are A Plague Of Biblical Scope In 2020. Why? And … What Are They Exactly?”:

Locusts are ravenous eaters. An adult desert locust that weighs about 2 grams (a fraction of an ounce) can consume roughly its own weight daily. And they’re not picky at all. According to the FAO, a swarm of just 1 square kilometer — again, about a third of a square mile — can consume as much food as would be eaten by 35,000 people (or six elephants) in a single day.

“When they do descend, they can have almost total devastation,” Overson says. “They can cause 50 to 80% of crops to be destroyed, depending on the time [of year].”

The last large locust outbreak, which started in 2003 and lasted until 2005, resulted in an estimated $2.5 billion in crop damage. Studies found that the economic effect was largely felt by subsistence farmers. Children who grew up during the period were much less likely to go to school, and girls were disproportionately affected.

(We’ll look at subsistence farmers in Nepal and India, especially.) And to review, locust swarming behavior is fascinating. From Forbes, “What’s Up With Those Locust Swarms?“, in layperson’s terms:

Trouble starts when an environmental change improves conditions for the insects and lets them breed rapidly. The locusts sense the change in their population through sight, smell, and by physically bumping into other individuals, said Rick Overson, a locust expert at Arizona State University’s Julie Ann Wrigley Global Institute of Sustainability.

The increased population density alters locusts’ appearance and brain chemistry, causing them to start moving together in large groups, or swarms. Scientists once believed solitary and swarming desert locusts were two different species because they look and behave so differently, said Overson. He said juvenile locusts that can’t fly yet will march together as nymphs when they are in their swarming state.

It isn’t completely clear why locusts swarm. Overson said one hypothesis is that since locusts’ habitats can change quickly and unpredictably, the swarms help them move to where there is more rain and food in case good conditions don’t last.

(This NC post contains a more science-y explanation of swarming, if you wish to read and retain words like “density-dependent phenotypic plasticity,” and “phase polymorphism.”) If you’re an entemologist, being inside a swarm is pretty neat. From the Harvard Gazette, “East Africa facing massive swarms of locusts”:

When you’re in a swarm, especially if it’s just as they’re getting moving, it’s actually quite an incredible experience. You see, they change color when they’re young — they’re more pinkish and then as they mature they become yellow — so when they are flying around you at that stage, you have all these pink and yellow wings whirring around and a slightly nutty smell of the locusts surrounding you and lots of birds feeding on them.

(The “slightly nutty smell” translates, I imagine to flavor; some consider locusts a delicacy.) With that, let’s move on to the Indian subcontinent.

The Indian Subcontinent

First, the map. From the “Desert Locust Watch” of the United Nations Food and Agriculture Organizations (FAO), here is a map of the current situation:

(Note the arrow from Pakistan into India.) Just for shock value, from India:

I’m amazed to see the trees swaying under the impact of the swarm. And for amusement:

It’s gonna take more than onesies and twosies!

With that, let’s look at the individual countries. I’ll start with Nepal, because there I have a worked example of the effects of a locust infestation on a subsistence farmer (as above,” studies found that the economic effect was largely felt by subsistence farmers. Then I’ll move Pakistan and India, focusing on actions taken at ground level (since we already know locusts are bad, eat everything up, cause “food insecurity,” etc.).


From the Katmandu Post, “Eight million locusts have entered Nepal, consuming hundreds of hectares of crop“:

Lal Bahadur Kewat of Lohraula in Buddhabhumi Municipality, Kapilvastu was busy transplanting paddy on Monday when his neighbour informed him that a swarm of locusts had descended on his vegetable farm.

By the time Kewat reached his farm, his green beans and bitter gourds on one-and-a-half katthas of land had already been destroyed.

“Everything was completely ravaged. I just cried looking at the loss,” said Kewat. “We [farmers] are being hit from everywhere.”

Kewat had taken a loan of Rs20,000 for his vegetables, which had just begun to bear fruit. With green beans and bitter gourds in season, he had hoped to earn Rs150,000.

“It’s all gone,” said Kewat, who has a family of six to feed.

(Obviously, Kewat should learn to code.) 1.5 katthas is 0.12 acres, so even though Kewat is a landowner — at least for vegetables, though not for rice — his land is tiny. The NPR150,000 Kewat hoped to gross is $1,256, above Nepal’s per capita income of NPR106,333 ($1,004). But now Kewat is in debt NPR20,000, or $167, which sounds small, but a man can drown in six inches of water. Multiply Kewat’s predicament by however many hundreds of thousands or millions are in the path of the swarms.


Now let’s look at Pakistan, which is applying pesticides. From the Associated Press of Pakistan, “Anti-locust operation completed over 2.294 million acres : NLCC“:

ISLAMABAD, Jul 04 (APP):The anti-locust operations have been carried out in 9, 297 square kilometers, approximately 2.2927 million acres of land across 31 affected districts of the country in order to eradicate the locusts swarms.

As many as 966 joint teams comprising over 5,082 people took part in the anti-locusts operations across the country, according to details released by the National Locust Control Center (NLCC).

(Surprisingly, given that the swarms crossed Pakistan on their way the India, the infestation seems not to have been politicized.) Pesticides as standard operating procedure, but this program is hearteningly ingenious. From Phys.org, “Pakistan battles locusts by turning them into chicken feed“:

At night the creatures cluster on trees and plants, making them easy to scoop up as they lie motionless in the cooler temperatures until the sun begins to rise.

Key statistics on the desert locusts which are decimating harvests in Pakistan’s agricultural heartlands

For a reward of 20 rupees (12 cents) per kilogram of locusts, locals worked all night to collect them.

One farmer who lost all her crops to the insects [like Kewat] said she and her son earned 1,600 rupees ($10) during a single locust-gathering outing, helping to offset the financial damage.

With 20 tonnes of captured locusts, authorities ran out of money to pay the collectors and the programme was paused.

The harvested locusts went to Hi-Tech Feeds—Pakistan’s largest animal-feed producer—which substituted 10 percent of the soybean in its chicken food with the insects.

While the project is not a solution to the devastation caused to crops, it can provide hard-hit farmers with a fresh revenue stream and relieve pressure on authorities struggling to distribute locust-beating pesticides.

20 tonnes! In one village! Holy moley! Give this program more money! Just for confirmation, here is an account that participated in the program.

So now chickens can enjoy that nutty goodness. (This also sounds like a much better program than the 100,000 ducks China was going to send.)


So now we turn to India. From the New York Times, “India’s Capital Faces a ‘Swarmageddon’ of Locusts“:

But as a new planting season nears, farmers worry that more than 200 million acres of rice, sugar cane, cotton and soybeans could be decimated. In parts of Rajasthan, more than 60 percent of crops have been damaged, and a government relief package has covered only a small fraction of farmers, according to local news outlets.

The coronavirus has complicated efforts to stop the locusts. With confirmed infections topping 500,000 nationwide and many cities still under partial lockdowns, officials have strained to keep supply chains open and enforce locust containment measures across state borders.

(There’s something about a plague of locusts that seems to cause some Western editors, who write the headlines, to really go funny-not funny: “Crunch, crunch,” “Swarmageddon.”) From the Hindustan Times, “Six states on high alert as govt warns of more locust swarms“:

In a year punctuated by cyclones, heat waves, surging coronavirus infections and overwhelmed hospitals, scientists warn that the locusts could push agrarian parts of India to the brink of disaster, severely disrupting food supplies and slashing earnings for millions of struggling farmers.

Operations to control infestation are continuing in six states — Rajasthan, Madhya Pradesh, Punjab, Gujarat, Uttar Pradesh, and Haryana — by locust circle offices. The invasions have caused “minor crop losses”, according to a status update till July 3.

The crop losses, so far, are minor, since India is the “lean season” between harvesting and planting. However, the Times of India warns, in “Locust menace: FAO asks India to be on high alert for next 4 weeks,” warns:

NEW DELHI: India should remain on high alert against locust attack for the next four weeks, the [FAO] has warned amid the country facing the worst locust attack in 26 years. The FAO said spring-bred locust swarms, which migrated to Indo-Pakistan border and travelled east to northern states, are expected to return back to Rajasthan with the start of the monsoon in coming days.

These swarms will return to Rajasthan to join other swarms still arriving from Iran and Pakistan, which is expected to be supplemented by swarms from the Horn of Africa in about mid-July, it added.

“Early breeding has already occurred along the Indo-Pakistan border where substantial hatching and band formation will take place in July that will cause the first-generation summer swarms to form in mid-August,” FAO said.

Measures recommended for Indian farmers, from NDTV: “Make Noise, Shut Windows: Gurgaon Administration Warns Of Locust Attack“:

Gurgaon residents must keep their windows shut as precaution against a possible attack from crop-destroying desert locusts, the city administration said on Friday as a swarm was sighted at an adjoining Haryana district. The administration has asked them to make clanging noise by beating utensils to ward the insects off.

Pot-banging and drumming is also recommended in Africa; it seems cargo cult-like to me, but insects do have a sense of hearing, so maybe it works. One farmer believes so. From Newsclick, “Sleepless Nights for UP Farmers as Locusts Damage Crops in Several Areas“:

“I couldn’t sleep for a minute since locust swarms were moving freely around the whole night. I kept shooing them away the whole night, making loud noises by beating utensils,” said 65-year-old Hukum Singh, a farmer in Mathura village.

Well, if the locusts were shooed away, excellent. Further recommendations include neem oil:

What seems to be unique to India is the use of drones and helicopters. From the World Economic Forum, “Drones and helicopters are battling India’s fast-spreading locust swarm“:

India have deployed a helicopter and a dozen drones spraying insecticide to stop desert locusts that have spread to nine heartland states of the world’s second-biggest producer of rice and wheat.

India, battling its worst desert locust outbreak for decades, pressed into service 12 drones to track the movement of locusts and spray insecticides on the swarms.

It seems, however, that drones have their limitations. They are useful only for locusts in trees:

Further, drones are not suitable for dense swarms. From The Conversation, “Huge locust swarms are threatening food security, but drones could help stop them“:

Drones don’t perform well in areas that are densely packed with locusts, due to damage to propellers. And while the technical specifications of drones have made rapid improvements over the past few years, they still only provide a limited load of insecticide for spraying.

(Plus some editor’s funny-not funny subhead, “Some bugs remain,” ffs.) I can’t help but think that the Pakistani incentive program would be useful in India. I mean, can drones spraying pesticides really kill 20 tonnes of locusts? And can those same locusts then be fed to chickens?

South America

From the Indian subcontinent, we turn to South America, where thankfully there is only one swarm. El Globo provides the following map:

(The red dots, captioned “Peligro,” mean danger.) The Sun, of all places, provides a more dramatic version:

One locust swarm is much like another, at least to a layperson, but for completeness:

Information on the Latin American swarm, at least in English, is very thin. (Oddly, the FAO’s “Desert Locust Watch” does not include Latin America. Perhaps the species is different?) From Reuters, “Argentina, Brazil monitor massive locust swarm; crop damage seen limited”:

Argentina and Brazil are monitoring the movement of a 15-square-kilometer locust swarm in Argentina’s northeast, though authorities and specialists said so far it had not caused significant damage to crops in the South American countries. Argentine food safety body SENASA said the swarm, which initially entered Argentina from Paraguay in late May, contained about 40 million insects. It is in the province of Corrientes, near borders with Brazil, Uruguay and Paraguay.

Argentina and Brazil are among the world’s largest soy and corn exporters.

“We are following the movement of the plague,” Héctor Medina, a coordinator at SENASA, told Reuters on Thursday. Due to the arrival of a cold weather front from the south, the movement of the locusts would be limited in the coming days, he added.

And a handy tip for the farmers in Nepal, Pakistan, and India. In addition to pesticides:

“My grandfather dealt with locusts many years ago. Farmers used to dig ditches in the ground, cover insects with soil, and then set them on fire,” [Eugenio Hack of the Copercampos cooperative in Santa Catarina] said.


So why so many swarms now? In a word, climate. From the Washington Post, “The world’s climate catastrophe worsens amid the pandemic“:

Scientists suggest the magnitude of the new swarms is a direct consequence of warming temperatures in the Indian Ocean, which created a pattern of torrential rainfall and cyclones that yielded more fertile breeding grounds for the locusts. Though much of the Indian spring harvest was collected before the locust swarms arrived, the Horn of Africa region could suffer up to $8.5 billion in lost crops and livestock production by the end of the year as a result of this locust outbreak, according to World Bank estimates.

“Nations which were already under threat of food insecurity now face a real danger of starvation,” Rep. Christopher H. Smith (R-N.J.) said in a statement touting bipartisan legislation in the House to boost aid to African countries affected by the infestation. “There are now up to 26 million people who are at risk of acute food shortages and widespread hunger.”

What would it cost to save 26 million people from starvation, and $8.5 billion in lost crops? A pittance. From the FAO, “Government of the Federal Republic of Germany contributes 2.3million EUR to boost FAO’s fight against Desert Locusts in Uganda“:

FAO considers the fight against the rapid spread of Desert Locusts in East Africa one of its top priorities. Therefore, as part of its global appeal to support the fight against the Desert Locust outbreak, safeguard livelihoods and promote early recovery, FAO issued an emergency humanitarian appeal totaling $153.2 million. So far, the agency has received $117.3 million in donations from national governments, foundations and other organizations including the Federal Republic of Germany. FAO in Uganda has so far mobilized USD 10 million from its core resources and development partners.

$153.2 million? Really? That’s only ten of Obama’s house on Oak Bluffs Martha’s Vineyard. Or Jeff Bezos could check under his couch cushions for loose change. If only there were “the political will.” From NPR once again:

There’s a slate of international institutions that coordinates locust management and response. The primary effort is conducted by the United Nations Food and Agriculture Organization, which runs the Desert Locust Watch to surveil and track locust migration patterns and oversee regional response efforts [but not in South America].

In individual nations, a lack of cash, competing priorities and domestic challenges make it hard to mount a long-range pest management strategy. Because locust numbers ebb and flow, Overson says it’s been difficult for countries — such as Kenya, which hasn’t seen an infestation in 70 years — to build up intermediate and long-term infrastructure to address outbreaks proactively. That’s why so many governments are now scrambling to come up with solutions.

“It’s hard to maintain funding and political will and knowledge and capacity building when you have these unpredictable boom and bust cycles that could play out over years or decades,” he says. “The drama and spectacle of the outbreak right now is important to cover, but the more nuanced narrative involves the slow, ratchet method of building infrastructure: If you wait until it’s reactive and forget about it until it happens again, we’re going to be in this situation forever.”

Just like COVID-19. Of course, there can’t possibly be a plague of locusts here, so there’s nothing to worry about. Except not. From Geocurrents, “Mapping Locust Swarms“:

The most widespread species, the migratory locust, has declined in recent years, its last major African “plague” occurring in 1942. The reasons for its waning do not seem to be fully understood.

The biggest locust mystery surrounds the species that was responsible for the largest swarms, the Rocky Mountain locust of North America. One outbreak in 1875 was estimated to have contained 12.5 trillion grasshoppers, which together would have weighed some 27.5 million tons. Yet within thirty years, the species was extinct, and since then North America has been virtually locust-free.* The cause of its extirpation has never been determined, although it has been argued that “the plowing and irrigation by settlers disrupted the natural life cycle of the insects in the very small areas they existed in between swarms.” Yet vast areas of the Great Plains, the core habitat, were never plowed, and irrigation was rare here in the late 1800s. Nor was overgrazing the likely cause. Recent research conducted jointly by scientists at the University of Arizona and the Chinese Academy of Sciences determined that extant locusts thrive on “low-protein, high-carbohydrate diets, typically found in overgrazed areas.”

Fingers crossed!

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