India faces its worst locust swarm in nearly 30 years

The pests have destroyed over 50,000 hectares of cropland, putting further strain on the food supply in India as authorities battle to contain the coronavirus.



On Tuesday, Indian authorities sent out drones and tractors to track desert locusts and spray them with insecticides, in one of the worst locust swarms seen by the country in nearly 30 years. With about 50,000 hectares of cropland destroyed by locusts, India is facing its worst food shortages since 1993.

"Eight to 10 swarms, each measuring around a square kilometer, are active in parts of Rajasthan and Madhya Pradesh," K.L. Gurjar, the deputy director of India's Locust Warning Organization, told news agency AFP. The locusts have also made their way to other states of India including Maharashtra and Uttar Pradesh.

On Monday, a swarm of locusts infested the city of Jaipur in Rajasthan, after traveling into India from Pakistan. Gurjar warned that the locusts could move towards the capital city of Delhi if wind speed and direction was favorable.


More than half of the 33 districts in Rajasthan were affected by the locusts

Why a locust swarm is alarming

According to the Food and Agricultural Organization (FAO) desert locusts typically attack the western part of India and some parts of the state of Gujarat from June to November. However, the Ministry of Agriculture's Locust Warning Organization spotted them in India as early as April this year.

A swarm of 40 million locusts can eat as much food as 35,000 humans, according to FAO estimates. The current swarm has destroyed seasonal crops in the states of Rajasthan and Madhya Pradesh. This will lead to lower production than usual and a rise in prices of foodstuff.

An agrarian crisis and subsequent food inflation will severely impede India's response to the coronavirus pandemic. Thousands of migrant workers have died from hunger after India suddenly imposed a nationwide lockdown to contain the spread of the coronavirus, leaving workers penniless. An agrarian crisis because of a locust swarm will further hamper relief efforts of the government.

Heavy rains and cyclones in the Indian Ocean are being cited by experts as reasons for increased breeding of locusts this year. The attack is also spread over a wider geography in India. The FAO has warned that the locust infestation will increase next month, when locusts breeding in East Africa reach India.

Other parts of the world affected by locusts

India isn't the only country attacked by a huge swarm of locusts this year. Pakistan,countries in East Africa, and Yemen have also faced the desert pests and their destruction. In February, Pakistan declared a national emergency because of locust attacks in the eastern part of the country. The pests damaged cotton, wheat, maize and other crops.

Earlier this month, the FAO said that it had made a headway in dealing with the locust invasion by saving 720,000 tons of cereal in 10 countries

Date 27.05.2020

Related Subjects India

Keywords India, locusts, crops, famine

Permalink https://p.dw.com/p/3coS


Historic swarm of locusts descends upon India, destroying cropsMay 27 (UPI) -- India is experiencing a historic swarm of locusts as the country also deals with the COVID-19 pandemic and sweltering heat.

Swarms of desert locusts have descended upon portions of the states of Rajasthan, Gujarat, Maharashtra, Madhya, Pradesh, Punjab and Uttar Pradesh, while alerts were issued in the capital city of Delhi warning the insects could soon arrive there.

India's Locust Warning Organization has said at least 10 swarms of up to 80 million locusts have made their way through India, destroying crops.

The organization said locust infestation is the worst the country has ever seen, coming before their usual migration from Pakistan between July and October and extending far beyond Rajasthan, where they have historically been centralized

Experts say that extreme heat in the nation, which has reached highs of 122 degrees, has contributed to the uncommonly large swarm.

"The outbreak started after warm waters in the western Indian Ocean in late 2019 fueled heavy amounts of rains over east Africa and the Arabian Peninsula," Dr. Roxy Mathew Koll, a senior scientist at the Indian Institute of Tropical Meteorology, said. "These warm waters were caused by the phenomenon called the Indian Ocean Dipole -- with warmer than usual waters to its west and cooler waters to its east. Rising temperatures due to global warming amplified the dipole and made the western Indian Ocean particularly warm."

The swarms have destroyed about 123,500 acres of cropland in the Rajasthan and Madhya Pradesh state.

States, including Jaipur, have deployed drones to spray locusts in order to clear the areas of locusts.

"It has successfully contained the movement of locusts in an open area and on the foothills where it was not possible for the usual tractors to make it reach. A detailed assessment of its impact is being studied by the field officers," said Om Prakash, commissioner of the Jaipur state agriculture department.

The drones are attached with spray tanks that can disperse chemicals for 10 minutes before being refilled by a handler.

"The biggest advantage of the drone is that it can fly above the flying zone of the locusts giving the flexibility to the officials to carry out combat operation while they are flying. Earlier, the operations were restricted to when they are resting n a tree or on a crop," Prakesh said

SEE
https://plawiuk.blogspot.com/2020/05/india-wilts-under-heatwave-as.html

https://plawiuk.blogspot.com/2020/05/data-analysis-how-east-africa-is.html


https://plawiuk.blogspot.com/2020/05/covid-19-locusts-and-floods-east.html

Chemical signal protects migratory locusts from cannibalism

Migratory locusts release a toxic substance to fend off their own conspecifics

Peer-Reviewed Publication

MAX PLANCK INSTITUTE FOR CHEMICAL ECOLOGY

 

IMAGE: A MIGRATORY LOCUST LOCUSTA MIGRATORIA EATS A CONSPECIFIC. CANNIBALISM IS CONSIDERED ONE OF THE MAIN DRIVERS OF THE DEVASTATING SWARMING BEHAVIOR OF LOCUSTS. view more 

CREDIT: BENJAMIN FABIAN, MPI FOR CHEMICAL ECOLOGY

Huge swarms of migratory locusts take on the proportions of natural disasters and threaten the food supply of millions of people, especially in Africa and Asia.  As the eighth of the ten biblical plagues, the Book of Moses in the Old Testament already describes how swarms of locusts darkened the sky and ate up everything that grew in the fields and on the trees.  Scientists suspect that cannibalism among locusts contributes to their swarming behavior, and swarms therefore constantly move on because individual animals are always on the run from conspecifics pursuing them. "We wondered how these insects influence each other's behavior within huge swarms, and whether olfaction plays a role. An important basis for us was the research on the formation of locust swarms by Iain Couzin of the Max Planck Institute for Behavioral Biology in Constance," says study leader Bill Hansson, director of the Department of Evolutionary Neuroethology at the Max Planck Institute, explaining the starting point of the study.

Migratory locusts occur in different phases: In the solitary phase, the insects live individually and stay in the area, while in the gregarious phase they exhibit the typical swarming behavior that fits their denomination as migratory locusts. "In most cases, locusts are in the solitary phase, where they avoid physical contact with conspecifics and eat comparatively little food. If the population density increases due to rainfall and sufficient food, the locusts change their behavior within a few hours; they can smell, see, and touch each other. These three types of stimulation increase serotonin and dopamine levels in the locust brain, causing solitary locusts to become aggressive gregarious locusts that are very active and have a large appetite.  They also release aggregation pheromones, which eventually leads to swarming and poses a huge threat to agricultural production. Cannibalism does only occur in the gregarious phase," explains the study's first author Hetan Chang.

Behavioral experiments with the migratory locust Locusta migratoria showed that cannibalism rates increased with the number of gregarious animals that were kept together in a cage. Thus, there is a direct relationship between population density and cannibalistic behavior.  To find out if gregarious locusts emit particular odors that are not produced in the solitary phase, the research team analyzed and compared all odors emitted by solitary and gregarious locust in the juvenile stage. Of the 17 odors produced exclusively in the gregarious phase, only phenylacetonitrile (PAN) turned out to be an odor signal that deterred other locusts in behavioral tests. For further confirmation of PAN's function, the scientists used genetically modified locusts that could no longer produce PAN. "We showed that as population density increased, not only did the level of cannibalism rise, but the animals also produced more PAN. Using genome editing, we were able to knock out an enzyme responsible for the production of this compound. This allowed us to confirm its strong anti-cannibalistic effect, because cannibalism was again significantly increased when the animals were no longer able to produce the compound," says Hetan Chang.

The biggest challenge was finding the olfactory receptor that recognizes PAN. Since locusts have more than 140 olfactory receptor genes, the research team had to clone as many genes as possible and test them one by one. Tests on 49 different olfactory receptors using more than 200 relevant odors eventually led to the identification of the olfactory receptor OR70a as a highly sensitive and specific detector of PAN in the migratory locust Locusta migratoria. Behavioral experiments with genetically modified locusts whose OR70a receptor was no longer functioning again showed a strongly increased cannibalism rate, which is due to the fact that the cannibalism stop signal can no longer be perceived by the locusts without the corresponding receptor.

A pheromone that controls cannibalism is an absolute new discovery. Because cannibalism has a major impact on locust swarm dynamics, a fundamental understanding of the population ecology of these animals, particularly the effect of PAN, opens up new possibilities of locust control. "If you inhibit the production of PAN or the function of the receptor, you could get the locusts to behave more cannibalistically and potentially control themselves in that way," Bill Hansson says.

---

JOURNAL

Science

DOI

10.1126/science.ade6155 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

A chemical defense deters cannibalism in migratory locusts

ARTICLE PUBLICATION DATE

5-May-2023

How East Africa is fighting locusts amid coronavirus

DATA ANALYSIS
East Africa is battling its worst locust invasion in decades. Amid the COVID-19 crisis, countries are fighting to stop a new generation of locusts swarms, which could jeopardize food security.




Since 2019, East Africa has been desperately trying to control a devastating desert locust invasion. The long rains that typically fall across the region from March to May this year will probably allow yet another generation of locusts to mature, further threatening crops and livelihoods.

This would be an additional blow to food security in East African countries, which are also facing economic disruption from the coronavirus pandemic response.

Read more: Severe hunger threatens Africa during COVID-19 lockdowns

In the region, swarms of desert locusts covered more than 2,000 square km – an area as big at Ethiopia's Lake Tana – in April alone.

Swarms of this size are made up of billions of insects, which can obliterate vegetation, eating more in a day than the combined population of Kenya and Somalia do.
https://www.dw.com/en/locusts-hit-east-africa-during-coronavirus/a-53357078
Watch video

UN sounds alarm as locusts spread in East Africa

Ethiopia and Kenya are currently the worst hit by the locust infestation.

New waves of locusts are forecast for the coming months in Kenya, southern Ethiopia and Somalia as seasonal rains create favorable breeding conditions.


"The next generation of swarms will be around late June or early part of July," says Keith Cressman, senior locust forecasting officer at the UN Food and Agricultural Organization (FAO).

The timing is particularly worrying as this would coincide with the start of the harvest season.

Crops wiped out

Desert locust swarms strip almost all green vegetation from crops and trees over immense areas, leaving behind ravaged fields and pasture lands and putting both farmers and pastoralists at risk of severe food shortages.

It's predicted more than 25 million people in East Africa will experience food insecurity in 2020 with the locust infestations compounding the situation.


Some farmers lost 90 percent of their crops in the first wave of locust to hit Ethiopia, says Yimer Seid of Ethiopia's South Wollo agricultural department.

"I visited families who have no food in their house. They sold their animals," he says.

Perfect conditions for desert locusts

A disastrous combination of circumstances fueled the current desert locust plague.

In 2018, two cyclones in succession unleashed rain in the immense sandy desert on the southern Arabian Peninsula known as the Empty Quarter. The moist sand and sprouting vegetation provided favorable conditions for the locusts to thrive.

Solitary desert locusts are usually harmless. If they are packed densely enough, however, the insects change behavior and even appearance, forming large groups that devour everything in their path. Groups of young, wingless locusts form bands, which eventually mature into fast-moving swarms.

In the Empty Quarter, the locusts multiplied unnoticed for three generations, increasing their original number 8,000-fold before swarms migrated up the Arabian Peninsula to Yemen.

https://www.dw.com/en/locusts-hit-east-africa-during-coronavirus/a-53357078

Watch video Locusts threaten food security in East Africa

Locusts are common in Yemen but its ongoing civil war has devastated the country's ability to monitor and fight the insects.

From Yemen, in 2019 the desert locust swarms traveled north to Iran then to Pakistan and India.


They were also carried on the wind across the Red Sea to northeastern Ethiopia, south Eritrea and Somalia, where higher than average rainfalls over the 2019 summer allowed the locusts to proliferate.

Ongoing locust crisis

That's when FAO declared an emergency, increasing and prioritizing equipment and monitoring efforts.

"We started fast tracking everything because we knew the situation was going to be out of control very quickly," says Cressman from the FAO.

But despite FAO and other organizations moving as fast as they could to curb the spread of the locusts, their sheer numbers meant they were already hard to control.

In December 2019, the insects started swarming into Kenya in what has turned into the worst outbreak the country has experienced in 70 years.


To make matters worse, East Africa's short rains, which normally fall from October to December, continued into 2020, allowing this first wave of swarms to mature and start laying eggs.

Now, the region has to fight this new generation as it hatches, before it creates the new swarms predicted for June.

Fighting the locusts

Managing locust swarms is best done before they even form. Regular monitoring is essential, since small numbers of the insects can be controlled relatively easily.

"It's not difficult to kill a locust. You put pesticide on the locust and it dies," says Cressman.

Normally, this is done by teams on the ground spraying pesticides from hand-held tanks, reinforced by planes or helicopters.

Read more: Why locusts are so destructive in East Africa

The problem with the current infestation is its sheer scale, he says.

"It's like a forest fire. If you find it really small as a campfire, you just put it out. But if you miss it, then it becomes a wildfire, and the problem gets much more difficult and expensive to control."

Time of the essence
Countries like Kenya, having little recent experience with locusts, took a few months to set up control operations. With locusts multiplying exponentially, that's valuable time lost.

Authorities in the affected countries have already sprayed pesticides on thousands of hectares of land. But if the weather conditions don't dry up, that might not be enough.

Control operations are falling behind: In April, only a quarter of the area affected by locusts was treated. Locust populations are expected to increase 20- or even 400-fold in the months to come.


Locusts multiply faster than control operations can keep up.

Helping hands

Spraying isn't the only way of weathering the devastation caused by the locusts.

In Ethiopia's South Wollo Zone, the community worked together in 2019 to bring in the harvest before the locusts could devour them.

"We harvested the crops in cooperation with everyone," says Yimer Seid. "There would have been around 100 people in a large field …, all volunteers from the region."

He's also seen more examples of people in the community sharing crops and food with each other to make sure people don't go hungry.

Two crises at once

The coronavirus pandemic makes such community action much harder. Although Ethiopia isn't under a strict lockdown, the movement of people is restricted by a national emergency decree.

Normally, agricultural officers in South Wollo would monitor the locusts in the field, explained Seid. Now farmers send in their reports online or over the phone, making it harder to assess the situation.

Overall, though, monitoring efforts and pesticide spraying operations are continuing in Ethiopia as locust control counts as an essential service.


But with new swarms on their way, Ethiopia desperately needs to scale up its operations, says Fatouma Seid from FAO Ethiopia. This should include "more teams on the ground, more vehicles for the government and more pesticides on the ground in addition to the air control."

However, the current stock of pesticides will only tide over locust control in Ethiopia up to June, she says.

As for neighboring Somalia, the country currently has enough pesticide at hand to spray around 2,000 square km.

That will cover the first phase of controlling hoppers (the juvenile locust, which can't fly) up to July, says Alphonse Owuor, Crop Protection Officer with FAO Somalia.

More pesticide is available if needed, Owuor says.

"We have been in constant contact with the supplier since late 2019. They are aware of our requirements for the rest of the year and are on standby on the event we will need more supplies urgently."

Anticipating future invasions difficult

African countries are much better equipped to tackle the locust threat than they used to be.

In the past, locusts plagues regularly swept across the continent. In the 1950s, the insects ate their way through countries in West and East Africa all the way to India and Pakistan in a plague lasting 13 years.

But in the last few decades, thanks to better monitoring and control, the infestations have tended to last for a shorter time and cover less area. Ethiopia and Somalia, for example, haven't experienced an outbreak of this scale in 25 years


Now though, predicting locust invasions has become harder is harder as weather patterns become more erratic due to climate change change.

"The desert locust is just one long, continuous story," says Cressman. "It's about figuring out the current chapter of that story."

DW RECOMMENDS


World Food Program: Act now to prevent coronavirus famine

The coronavirus will lead to a famine of "biblical proportions" unless aid can reach those in dire need immediately, warns the UN agency. But the pandemic is only amplifying famine's causes, which also need tackling. (23.04.2020)

Pakistan declares national emergency over locust swarms

Prime Minister Imran Khan declared the emergency to protect crops and help farmers. The Pakistani government said it was the worst locust infestation in more than two decades. (01.02.2020) 

WWW LINKS

Data and code behind this analysis

More data-driven journalism by DW

Date 11.05.2020
Author Kira Schacht

Related Subjects Environment, Food security, Coronavirus

Keywords locusts, Coronavirus, East Africa, food security, environment, DDJ

Permalink https://p.dw.com/p/3bsc2

Locust swarms arrive in South Sudan, threatening more misery

AFP•February 18, 2020


Pest: Desert locusts are threatening millions of people in East Africa with hunger (AFP Photo/TONY KARUMBA)

Juba (AFP) - Swarms of locusts which are wreaking havoc across East Africa have now arrived in South Sudan, the government said Tuesday, threatening more misery in one of the world's most vulnerable nations.

Billions of desert locusts, some in swarms the size of Moscow, have already chomped their way through Ethiopia, Somalia, Kenya, Djibouti, Eritrea, Tanzania, Sudan and Uganda.

Their breeding has been spurred by one of the wettest rainy seasons in the region in four decades.

Experts have warned the main March-to-May cropping season is at risk. Eggs laid along the locusts' path are due to hatch and create a second wave of the insects in key agricultural areas.

The arrival of the locusts could be catastrophic in South Sudan, where war followed by drought and floods has already left six million people -- 60 percent of the population -- facing severe hunger.

Agriculture Minister Onyoti Adigo Nyikiwec said the locusts had crossed the eastern border with Uganda on Monday.

"The report came that these are matured. As you know locusts are like human beings, they send their reconnaissance ahead of time to make sure that whether there is food or not and if the area is good for breeding."

Meshack Malo, the Food and Agriculture Organization (FAO) representative in South Sudan, said about 2,000 locusts had been spotted so far, and if not controlled quickly, could have a devastating impact.

"These are deep yellow which means that they will be here mostly looking at areas in which they will lay eggs."

He said the FAO was training locals and acquiring sprayers and chemicals to try and combat the locusts. It is the first locust invasion in 70 years in the country.

Other countries have employed aircraft to spray the swarms, while desperate locals have employed tactics like banging pots and pans or shooting at them.

Nyikiwec said the government had prepared a contingency plan.

"We are training people who will be involved in spraying and also we need chemicals for spraying and also sprayers. You will also need cars to move while spraying and then later if it becomes worse, we will need aircraft."

Earlier this month Somalia declared a national emergency over the invasion.
The FAO says the current invasion is known as an "upsurge," the term for when an entire region is affected.

However, if the invasion cannot be rolled back and spreads, it becomes known as a "plague" of locusts.

There have been six major desert locust plagues in the 1900s, the last of which was in 1987-89. The last major upsurge was in 2003-05.




Huge locust outbreak in East Africa reaches South Sudan

MAURA AJAK, Associated Press•February 18, 2020

Huge locust outbreak in East Africa reaches vulnerable South Sudan

JUBA, South Sudan (AP) — The worst locust outbreak that parts of East Africa have seen in 70 years has reached South Sudan, a country where roughly half the population already faces hunger after years of civil war, officials announced Tuesday.

Around 2,000 locusts were spotted inside the country, Agriculture Minister Onyoti Adigo told reporters. Authorities will try to control the outbreak, he added.

The locusts have been seen in Eastern Equatoria state near the borders with Ethiopia, Kenya and Uganda. All have been affected by the outbreak that has been influenced by the changing climate in the region.

The situation in those three countries “remains extremely alarming,” the U.N. Food and Agriculture Organization said in its latest Locust Watch update Monday. Locusts also have reached Sudan, Eritrea, Tanzania and more recently Uganda.

The soil in South Sudan's Eastern Equatoria has a sandy nature that allows the locusts to lay eggs easily, said Meshack Malo, country representative with the FAO.

At this stage “if we are not able to deal with them ... it will be a problem,” he said.

South Sudan is even less prepared than other countries in the region for a locust outbreak, and its people are arguably more vulnerable. More than 5 million people are severely food insecure, the U.N. humanitarian office says in its latest assessment, and some 860,000 children are malnourished.

Five years of civil war shattered South Sudan's economy, and lingering insecurity since a 2018 peace deal continues to endanger humanitarians trying to distribute aid. Another local aid worker was shot and killed last week, the U.N. said Tuesday.

The locusts have traveled across the region in swarms the size of major cities. Experts say their only effective control is aerial spraying with pesticides, but U.N. and local authorities have said more aircraft and pesticides are required. A handful of planes have been active in Kenya and Ethiopia.

The U.N. has said $76 million is needed immediately. On Tuesday, U.S. Secretary of State Mike Pompeo during a visit to Ethiopia said the U.S. would donate another $8 million to the effort. That follows an earlier $800,000.

The number of overall locusts could grow up to 500 times by June, when drier weather begins, experts have said. Until then, the fear is that more rains in the coming weeks will bring fresh vegetation to feed a new generation of the voracious insects.

South Sudanese ministers called for a collective regional response to the outbreak that threatens to devastate crops and pasturage.

Locusts swarm into South Sudan as plague spreads

By Denis Dumo, Reuters•February 18, 20203 Comments

JUBA, Feb 18 (Reuters) - Swarms of locusts ravaging crops and grazing land across east Africa have reached South Sudan, already reeling from widespread hunger and years of civil war, the country's agriculture minister said on Tuesday.

The locusts crossed into southern Magwi county, on the border with Uganda, Minister Anyoti Adigo Nyikwach said.

Kenya, Somalia, Eritrea and Djibouti are battling the worst locust outbreak in decades, and swarms have also spread into Tanzania, Uganda and now South Sudan.

Desert locusts can travel up to 150 km (95 miles) in a day and eat their own body weight in greenery, meaning a swarm just one kilometre square can eat as much food as 35,000 people in a day, the United Nations says.

The invasion is worsening food shortages in a region where up to 25 million people are suffering from three consecutive years of droughts and floods.

Meshack Malo, South Sudan's representative for the U.N.'s Food and Agriculture Organization, said the locusts were mature and looking for breeding grounds that will form the basis of the next major infestation.

“These are deep yellow, which means that they will be here mostly looking at areas in which they will lay eggs,” he said.

Teams planned to mark the place where they lay eggs and then come back to kill the young insects in 14 days, he said, since poisoning the eggs in the ground could damage the soil.

At least 2,000 locusts had crossed the border, he said. During each three month breeding cycle, a single locust can breed 20 more, giving rise to the massive swarms that are now threatening crops on either side of the Red Sea.

Oil-rich South Sudan is recovering from five years of civil war that plunged parts of the country into famine in 2017 and forced a quarter of the population to flee their homes. In December, the U.N.'s World Food Programme said the food security outlook was dire after floods affected nearly a million people. (Writing by Katharine Houreld; Editing by Mark Potter)

Kenya: Panic as Desert Locusts Invade Farms in Embu County


FAO/Sven Torfinn
(file photo).

14 FEBRUARY 2021
The Nation (Nairobi)

By George Munene


The second wave of desert locusts has invaded Embu County, throwing residents into panic.

The voracious insects crossed over to the area from Kitui County and are wreaking havoc on farms in the expansive Mbeere South Constituency.

The most affected villages are Machang'a, Kanthenge, Riachina, Kaburu and Ndunguni where sorghum, millet and green grams are grown in large scale.

The insects were first spotted on Friday evening and are destroying crops, which the residents depend on for survival, at a very high rate.

According to the residents and Mbeere South MP Geoffrey King'ang'i, the insects appear to be very hungry because they were not sparing anything edible.

"They are feeding on crops as well as grass and shrubs. They are dangerous insects," said Mr King'ang'i.

The residents expressed fears that the locusts may wipe out their sorghum, millet and other crops if urgent measures are not taken to eradicate them.

Appeal for intervention

They appealed to the government to intervene quickly before they lose all their crops and pastures for their animals to the locusts which have spread over an area estimated to be 10 square kilometres.

The residents said efforts to chase away the voracious feeders have borne no fruit.

They said if the locusts are not controlled, famine is imminent in the area.

"We may starve if our crops are destroyed and, therefore, we call upon the government to help us eliminate the locusts which are spreading very fast," one of the residents, Mr John Runji, said.

The MP lamented that since the invasion was reported, no government official has visited the area to assess the situation.

"If the locusts are not sprayed, then my people will suffer as they depend on crops to feed and to educate their children," he said.

Mr King'ang'i observed that the locusts have landed in the area even before the residents recover from the adverse effects of the Coronavirus pandemic.


Read the original article on Nation.

Kenya: Swarms of Locusts Invade Mbooni in Makueni County



Haji Dirir/FAO
Locusts swarm (file photo).

1 FEBRUARY 2021
Capital FM (Nairobi)


Makueni — Swarms of locusts have invaded farms in sections of Makueni County Monday.

The locusts were spotted in large areas of Mbooni and Kaiti Constituencies in the County.

Makueni Agriculture County Executive Committee Member Robert Kisyula described the latest invasion as the worst in recent months.

Farmers interviewed expressed fears of the losses they are likely to incur following the invasion on their crops.

"The locusts came through, started to devour the only left crops in our farms," one farmer said, "Some have completely eaten all leaves, leaving only the stems."

Last month, Agriculture Cabinet Secretary Peter Munya said at least 15 counties were affected by the locusts invasion, but assured that efforts were in place to manage the situation.

The government has expressed optimism of eradicating the locusts' menace.

Munya said that 80 percent of the locust swarms that invaded the country during the second wave have so been treated and surveillance was underway to combat the rest.

He said that of the 75 swarms that have been identified, 66 of them have been treated.

Munya further announced that 15 counties were affected including Marsabit, Wajir, Garissa, Tana River, Lamu, Kilifi, Taita Taveta, Mandera, Machakos, Kitui, Isiolo, Samburu, Laikipia, Meru and Tharaka Nithi Counties.

"So far, the total number of swarms that settled in the Country between November 2020 and January 2021 are 75 out of which 66 have been treated reflecting a total area of 19,100 hectares. The exercise has thus largely been successful," Munya said.

Munya pointed out that 9 sprayer aircrafts have been deployed in different Counties which are adversely affected while 500 National Youth Service (NYS) personnel have been trained to help on ground control of the locusts.

"There are sufficient control pesticides both at the headquarters and all the field control bases to handle the desert locust invasion. Where necessary will purchase more," said Munya.

Additionally, 21 vehicles mounted with sprayers for ground control operations in the various bases.

The second wave started last year in November.

In March last year, Kenya and a number of countries in the horn of Africa including Ethiopia, Somalia and Uganda experienced the worst locust attack in seven years.

The first wave affected over 30 counties in Kenya with most of them being the Arid and Semi- Arid ones.


Read the original article on Capital FM.

East Africa braces for a return of the locusts

East Africa has not just suffered from the 2020 coronavirus pandemic, but also the worst locust plague in decades. Now, the swarms are returning, and experts are concerned about food security in the region.



The locust invasion in East Africa has deprived many farmers of their livelihood

Leion Sotik has lost everything. The farmer living in Garissa County, Kenya, still remembers what happened just a year ago, right during harvest season. The invaders came — and destroyed everything on his maize plantation. "I am very desperate," he told DW. "I was expecting a harvest to feed my family and take the children to school. Look at how my crops have been destroyed. Everything is gone now."

The culprits are one of the world's oldest pests and probably have their most famous reference in the Old Testament's Book of Exodus: Locusts. In 2020, a plague of the hoppers invaded East Africa, ravaging crops and pastures and driving the level of human hunger and economic hardship higher in parts of the region. One year later, right at the start of 2021, the United Nations has warned that a second and maybe even deadlier re-invasion of locusts has already begun.

The locusts are breeding and multiplying at an alarming rate

Trillions of locusts in East Africa

The first wave of the pests emerged at the end of 2019, numbering in hundreds of billions, multiplying by a factor of 20 per generation, according to the UN Food and Agriculture Organization (FAO). The second generation in March and April numbered in the trillions. A plague that spread like wildfire — up to now.

"It's a continuation of the 2020 locusts swarm. The adults have flown to various areas and are laying eggs", Frances Duncan, Professor of Animal, Plant & Environmental Sciences at the University of the Witwatersrand, told DW. "If we have good rains like it is the case at the moment in most areas, the hoppers will hatch, and we get the second wave of the swarm."

However, Keith Cressman, FAO's Senior Locust Forecasting Officer, remains optimistic. "I think it's still a very dangerous situation. But it should not be worse as it was last year." According to the weather forecast, the months to come should be dry, reducing the locusts' reproductive rate.

Threatening food security

Kenya was heavily affected by the worst invasion of locusts in 70 years. In Garissa, the insects have driven farmers into despair: Their farms' total yields in 2020 were destroyed in less than 24 hours.

Watch video 01:41 Somalia locusts threaten food supplies

Nur Fadhil remembers that they had no chance against the plague. "We have tried chasing the locusts away, but our efforts were in vain. The locusts spent the night on our farms. When we woke up the next day, they were still here. They had munched on everything on the farm. We have gone through massive losses," Fadhil said.


In an emergency case, the FAO is ready to step in, Cressman told DW in an interview. "We are constantly monitoring the locusts' situation, the weather conditions, and provide service to all countries in the world in terms of early warning and forecasting so they can be prepared to respond." The FAO is supporting control operations financially through pesticides, aircraft, and sprayers.

Cressman emphasized that the livelihoods of the population need to be protected. "If a farmer has crops planted and his crop has been wiped out, and he does not have resources to buy new seeds to replant, the FAO can assist. For pastoralists, if there is not enough food for animals, the FAO can provide animal feed."
Breeding in Ethiopia and Somalia

Five countries have been especially hard hit by the African migratory locusts: Ethiopia, Kenya, Somalia, Sudan, and Yemen. As a result, more than 35 million people suffer from food insecurity. FAO estimates this number could increase to 38.5 million if nothing is done to control the new infestation.

The FAO warns that numerous immature swarms have already formed in eastern Ethiopia and central Somalia during December, now they have reached northern Kenya. More swarms will arrive in January and spread throughout Ethiopia and Kenya.

"If the locust swarm is not controlled, it can completely destroy the crop and wipe out animal feed. This poses a serious threat to food security in the region and can lead to human and social crises," Amh Yeshewas Abay, Head of Natural Resources Office in South Omo Zone Hamer Woreda in Ethiopia, said in a DW interview. "We are working to eradicate locusts in northern Kenya and on the border with Somalia."
Danger of conflict

In northern Somalia, swarms laid eggs in areas affected by Cyclone Gati. Heavy rains in the region had turned out to favor the locusts, the UN says. New immature swarms could start to form in early February. Adult groups and a few swarms appeared on the coast of Sudan and Eritrea in December.

East Africa has seen the worst locust plague in decades

According to Daniel Lesego from Kenya's National Disaster Management Unit, the locust invasions come with multiple risks apart from food insecurity. "If there will be competition over pasture, space, and water, then it is likely to trigger conflict, resource-based conflict, and that is something that we do not want to see in Kenya," he told DW. "For us, this is a national call. It is a national duty that we are responding to and are committed to ensuring that locusts in Kenya are eradicated to make sure that locusts do not cross to our neighbors."
Is East Africa prepared?

1.3 million hectares of locust invasion were treated across 10 countries since January last year to stave off an economic and agricultural catastrophe, according to the UN. Countries have prepared themselves to use pesticides on the ground and from the air. It helped to prevent the loss of around 2.7 million tons of cereal.

"Countries have been alerted to this possibility for a couple of months. They have been preparing, mobilizing their teams and getting them into the field to doing the monitoring, identifying locusts and doing ground control operations, supported by aerial operations," Cressman said, adding that the goal would now be to treat as many swarms as possible, "before they spread, mature, and lay eggs for another generation of locusts."

The Kenyan government has set aside $30 million (€24 million) to fight the second wave. Agriculture Minister Peter Munya told journalists that Kenya is well-equipped to fight the locust swarms and promised that in counties where crops and livestock have been lost, the government would intervene to help distribute seeds, cereals, clean water, or fertilizers.

 

Good smells, bad smells: It’s all in the insect brain

Raman looks at natural and acquired preferences using locusts

Peer-Reviewed Publication

WASHINGTON UNIVERSITY IN ST. LOUIS

 

IMAGE: BARANI RAMAN AND HIS LAB AT THE MCKELVEY SCHOOL OF ENGINEERING STUDIED THE BEHAVIOR OF LOCUSTS AND HOW THE NEURONS IN THEIR BRAINS RESPONDED TO APPEALING AND UNAPPEALING ODORS TO LEARN MORE ABOUT HOW THE BRAIN ENCODES FOR PREFERENCES AND HOW IT LEARNS. view more 

CREDIT: PHOTO: RAMAN LAB, WASHINGTON UNIVERSITY IN ST. LOUIS

Everyone has scents that naturally appeal to them, such as vanilla or coffee, and scents that don’t appeal. What makes some smells appealing and others not?

Barani Raman, a professor of biomedical engineering at the McKelvey School of Engineering at Washington University in St. Louis, and Rishabh Chandak, who earned bachelor’s, master’s and doctoral degrees in biomedical engineering in 2016, 2021 and 2022, respectively, studied the behavior of the locusts and how the neurons in their brains responded to appealing and unappealing odors to learn more about how the brain encodes for preferences and how it learns.

The study provides insights into how our ability to learn is constrained by what an organism finds appealing or unappealing, as well as the timing of the reward. Results of their research were published in Nature Communications Aug. 5.

Raman has used locusts for years to study the basic principles of the enigmatic sense of smell. While it is more of an aesthetic sense in humans, for insects, including locusts, the olfactory system is used to find food and mates and to sense predators. Neurons in their antennae convert chemical cues to electrical signals and relay them to the brain. This information is then processed by several neural circuits that convert these sensory signals to behavior.

Raman and Chandak set about to understand how neural signals are patterned to produce food-related behavior. Like dogs and humans salivating, locusts use sensory appendages close to their mouths called palps to grab food. The grabbing action is automatically triggered when some odorants are encountered. They termed odorants that triggered this innate behavior as appetitive. Those that did not produce this behavior were categorized as unappetitive.

Raman and Chandak, who earned the outstanding dissertation award from biomedical engineering, used 22 different odors to understand which odorants the locusts found appetitive and which they did not. Their favorite scents were those that smelled like grass (hexanol) and banana (isoamyl acetate), and their least favorites smelled like almond (benzaldehyde) and citrus (citral).

“We found that the locusts responded to some odors and not others, then we laid them out in a single behavioral dimension,” Raman said.

To understand what made some odorants more likable and others not, they exposed the hungry locusts to each of the scents for four seconds and measured their neural response. They found that the panel of odorants produced neural responses that nicely segregated depending on the behavior they generated. Both the neural responses during odor presentation and after its termination contained information regarding the behavioral prediction.

“There seemed to be a simple approach that we could use to predict what the behavior was going to be,” Raman said.

Interestingly, some of the locusts showed no response to any of the odors presented, so Raman and Chandak wanted to see if they could train them to respond. Very similar to how Pavlov trained his dog with a bell followed by a food reward, they presented each locust with an odorant and then gave them a snack of a piece of grass at different time points following the odor presentation. They found that locusts only associated appealing scents with a food reward. Delaying the reward, they found that locusts could be trained to delay their behavioral response.

“With the ON-training approach, we found that the locusts opened their palps immediately after the onset of the odor, stayed open during the presentation of the odor, then closed after the odor was stopped,” Raman said. “In contrast, the OFF-training approach resulted in the locusts opening their palps much slower, reaching the peak response after the odor was stopped.”

The researchers found that the timing of giving the reward during training was important. When they gave the reward four seconds after the odor ended, the locusts did not learn that the odor indicated they would get a reward. Even for the appealing scents no training was observed.

They found that training with unpleasant stimuli led locusts to respond more to the pleasant ones. To explain this paradoxical observation, Raman and Chandak developed a computational model based on the idea that there is a segregation of information relevant to behavior very early in the sensory input to the brain. This simple idea was sufficient to explain how innate and learned preference for odorants could be generated in the locust olfactory system.

“This all goes back to a philosophical question: How do we know what is positive and what is negative sensory experience?” Raman said. “All information received by our sensory apparatus, and their relevance to us, has to be represented by electrical activity in the brain. It appears that sorting information in this fashion happens as soon as the sensory signals enter the brain.”

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Chandak R, Raman B. Neural manifolds for odor-driven innate and acquired appetitive preferences. Nature Communications, Aug. 5, 2023., DOI: 10.1038/s41467-023-40443-2.

This research was supported by the National Science Foundation (1453022, 1724218, 2021795) and the Office of Naval Research (N00014-19-1-2049, 955 N00014-21-1-2343).

Originally published by the McKelvey School of Engineering website.

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JOURNAL

Nature Communications

DOI

10.1038/s41467-023-40443-2. 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Neural manifolds for odor-driven innate and acquired appetitive preferences

ARTICLE PUBLICATION DATE

8-Aug-2023

 

Scientists rewrite the rules of swarming locusts

University of Konstanz

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image: 

Locust outbreak in East Africa

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Credit: Copyright: Einat Couzin-Fuchs, Inga Petelski, Yannick Günzel, Felix B. Oberhauser

Desert locusts, a notorious Biblical pest, form some of the largest insect groups in nature and are estimated to threaten the livelihood of one in ten people due to their impact on food security. Swarms begin when flightless juveniles aggregate and start marching in unison. Understanding how these plague insects coordinate their motion is crucial for developing evidence-based control, such as forecasting swarm movements. In addition, revealing the nature of inter-individual interactions is key to understanding how collective motion emerges among social animal species more broadly.

• A video can be found here: https://youtu.be/oBJnY4HKmeY

For decades, a principle borrowed from theoretical physics – treating individuals as "self-propelled particles" – has been used to model collective motion in animals. Similar to particles in physical systems like magnets, this hypothesis assumes that animals actively align with one another. However, unlike in magnets, these "particles" are constantly in motion. Such models have shown that even when individuals align only with their local neighbors, large-scale coherent movement can emerge, with vast numbers of individuals moving in the same direction.

The longstanding hypothesis also states that the density between the animals is a decisive factor for the change from non-coherent motion – where individuals move in random directions – to coherent large scale collective motion. When enough animals come together in a space, they are predicted to spontaneously transition from disordered to ordered swarm motion. This prediction was later seemingly corroborated by laboratory experiments with large locust groups, thereby strengthening the claims of these classical models.

Testing long-held hypotheses
Through a combination of fieldwork during East Africa’s locust outbreak of 2020, laboratory studies, virtual reality experiments, and a reevaluation of past data, researchers from the Cluster of Excellence "Collective Behaviour" at the University of Konstanz have concluded that the behavioural mechanisms governing collective motion in locust swarms cannot be explained by these classical models. Their findings challenge the traditional view by which collective motion is thought to emerge in animal groups.

"Inferring the mechanism of interaction in mobile animal groups is notoriously difficult", says Professor Iain Couzin, the study’s senior author, noting that "individuals both influence, and are influenced, by the behaviour of others in a complex interplay." To overcome this challenge, the Konstanz team leveraged immersive 3D virtual reality, enabling them to study how freely moving locusts interact with a computer-generated "holographic" virtual swarm. "This approach allowed us to rigorously test hypotheses about what drives their behaviour in ways that would be impossible in natural swarms", adds first author Dr Sercan Sayin.

The precise control of visual information afforded by virtual reality meant that the researchers could establish how sensory input is translated into movement decisions by locusts. Contrary to previous assumptions, the team observed that the "optomotor response" – an innate reflex in which locusts (and many other species) follow motion cues – is not responsible for coordinating collective motion. Indeed, they found no evidence that locusts explicitly align with the direction of motion of others at all.

In one virtual reality experiment, for example, focal locusts were placed in between two virtual swarms, one to their left and one to their right, both moving in the same direction. Classical models predict that under such circumstances, locusts should "go with the flow". However, the Konstanz team saw that locusts would turn to face one swarm, or the other, and move towards it.

Furthermore, the researchers found that group order is not simply a product of increasing density, as was previously thought. Alignment occurred in response to coherent visual cues, almost entirely independent of density. "It’s really about the quality of information, not the quantity", says Sercan Sayin. A reanalysis of a large number of previous laboratory experiments, which had argued for density-dependent transition to coherent motion, confirmed the Konstanz team’s findings, challenging previous assumptions about the behavioural mechanisms underlying swarming in locusts.

A new cognitive framework for collectives
In order to explain their results, it was necessary for the Konstanz team to rethink the approach of modeling collectives from the bottom up. "Locusts are not behaving like simple particles that align with one another", says Iain Couzin. "We realized that we need to model them as cognitive agents – processing their surroundings and making decisions about where to move next."

The research team developed a simple cognitive model, informed by the neurobiology of the neural circuits used by animals for spatial navigation, termed a "ring attractor" neural network. In this model, individuals have a simple neural representation of the bearing towards, but not the body orientation or direction of motion, of neighbours. Movement decisions emerge through a dynamic process in which neural representations compete or converge based on relative positioning, ultimately reaching a consensus that determines the direction of motion. "Our model is based on known neurobiological principles", explains Dr. Sayin, "and we found it can account for all of our key experimental findings".

The study, published in Science, represents nothing less than a paradigm shift in swarm research. By providing fundamental new insights into how locust behaviour results in devastating swarms, the Konstanz research may provide critical knowledge for improved locust control strategies, such as for effective modeling of swarm movement.

Moreover, the consequences of these findings will likely extend beyond locusts to broader applications in understanding the coordination of motion in other species, as well as robotics, artificial intelligence and the study of collective intelligence. Swarm robotics and autonomous vehicle coordination, for example, may benefit from algorithms inspired by locusts’ highly effective cognitive strategies for collective motion.

 

Key facts: Original publication: Sercan Sayin, Einat Couzin-Fuchs, Inga Petelski, Yannick Günzel, Mohammad Salahshour, Chi-Yu Lee, Jacob M. Graving, Liang Li, Oliver Deussen, Gregory A. Sword & Iain D. Couzin, The behavioral mechanisms governing collective motion in swarming locusts, Science387,995-1000(2025). DOI:10.1126/science.adq7832 Link: https://www.science.org/doi/10.1126/science.adq7832 This study was conducted by researchers in the Cluster of Excellence "Collective Behaviour" and the Max Planck Institute of Animal Behavior (MPI-AB). Iain D. Couzin is speaker of the Cluster of Excellence "Collective Behaviour", professor of biodiversity and collective behaviour at the University of Konstanz and director of the Max Planck Institute of Animal Behavior (MPI-AB). Sercan Sayin is a postdoctoral researcher in the Cluster of Excellence "Collective Behaviour" at the University of Konstanz.

Note to editors:
A video can be found here:
https://youtu.be/oBJnY4HKmeY

You can download photos here:

1. https://www.uni-konstanz.de/fileadmin/pi/fileserver/2025_extra/scientists_rewrite_1.jpeg

2. https://www.uni-konstanz.de/fileadmin/pi/fileserver/2025_extra/scientists_rewrite_2.jpeg

3. https://www.uni-konstanz.de/fileadmin/pi/fileserver/2025_extra/scientists_rewrite_3.jpg

Caption: Locust outbreak in East Africa
Copyright: Einat Couzin-Fuchs, Inga Petelski, Yannick Günzel, Felix B. Oberhauser
 

4. https://www.uni-konstanz.de/fileadmin/pi/fileserver/2025_extra/scientists_rewrite_4.jpg

Caption: Laboratory study with locust in the Imaging Hangar, University of Konstanz
Copyright: Christian Ziegler, Max Planck Institute of Animal Behavior (MPI-AB)

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Journal

Science

DOI

10.1126/science.adq7832 

 

Studying locusts in virtual reality challenges models of collective behavior

Summary author: Walter Beckwith

American Association for the Advancement of Science (AAAS)

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A study of locusts navigating in a novel virtual reality (VR) environment challenges traditional models of collective swarming behavior, researchers report. The findings show that the insects don’t just follow their neighbors like self-propelled particles but instead rely on internal cognitive decision-making processes to navigate as a collective. Collective motion, a phenomenon found widely in nature, has traditionally been described using "self-propelled particle" theoretical models from physics. These “classical” models of collective behavior, like the highly influential Vicsek model, explain how basic local interactions, where individuals align and synchronize their movements with those of nearby members, can give rise to large-scale, coordinated motion within groups. Desert locust (Schistocerca gregaria) swarms, which can cover vast areas and contain billions of individuals, serve as a prominent example of collective motion in nature. Using a combination of field experiments and an innovative virtual reality (VR) system in which locust nymphs moved freely, interacting with virtual locusts, while immersed in a 3D virtual environment, Sercan Sayin and collogues show that classical models of collective behavior fail to explain the motion exhibited by swarming locusts. Sayin et al. found that locusts do not follow the fixed interaction rules assumed by traditional models, such as explicitly aligning with their moving neighbors when the density of the swarm increases. Instead, locusts behaved as if they were drawn toward other locusts – a behavior that aligns with a minimal cognitive model of spatiotemporal decision-making where an individual makes directional choices based on their own internal consensus. “Sayin et al. conclude that it is time to move beyond the conception of locusts and other organisms as moving particles behaving according to fixed spatiotemporal rules and to consider organisms as probabilistic decision-makers responding dynamically to their sensory environment,” write Camille Buhl and Stephen Simpson in a related Perspective.

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Journal

Science

DOI

10.1126/science.adq7832 

Article Title

The behavioral mechanisms governing collective motion in swarming locusts

Article Publication Date

28-Feb-2025