CABI Invasives Blog
The locust invasions devastating Niger
It is the end of December 2016, with clear skies over Niger. But as 2017 draws near prospects are grim for some 500 residents in Bani Kosseye, a village 80km from the capital Niamey. Agricultural production has been poor here, and families’ meagre stocks are expected to run out within a few weeks. People already fear famine.The main cause for this food stress is none other than locusts. The damage the tiny insects cause to agriculture means they have become public enemy number one in the fields and pastures of this Sahel country.
The various institutions set up to combat the locust threat in Niger classify the insects into two main groups: desert locusts and grasshoppers. There is a third category, migratory locusts, but experts in Niger say these are not a significant threat.
Desert locusts, on the other hand — which are associated with the eighth biblical plague — have the ability to swarm into several dozen million individuals capable of travelling long distances across several countries to devastate fields. The 2003-2005 invasion affected 20 countries across northern Africa and destroyed millions of hectares of crops.
According to the preamble of Niger’s Locust Risk Management Plan, during a massive locust invasion swarms of desert locusts may invade “an area of 29 million square kilometres where 1.3bn people live, stretching from Africa’s Atlantic coast in the northern hemisphere to the Indo-Pakistani border, and from the Mediterranean to the Equator”.
Idrissa Maiga, a locust expert at the Agrhymet Regional Centre in Niamey, says “it is a species with an extraordinary reproductive capacity. Females may lay eggs several times during their lifetime and each female lays between 80 and 100 eggs.”
And how voracious are they? “Each individual is capable of eating its own weight in vegetable matter per day,” the entomologist says. “This means that each individual can eat up to two grams of fresh material per day.”
“Therefore, if a swarm of dozens or hundreds of millions of individuals zooms in on a crop, it only takes them between 15 and 30 minutes to destroy fresh material in the area,” Maiga says.
Millions of hectares destroyed
Some desert locust specialists, who are quoted in a technical note by Niger’s locust monitoring system (published in December 2016, in French) even say that “in theory, a swarm covering a 25-square-kilometre area with a density of 100 insects per square meter, may eat as much grass as 50,000 heads of cattle.”
The director general of the National Locust Control Centre (CNLA), Abou Moumouni, says Niger paid a very heavy price for the 2003/2005 locust invasion.
“3,755 villages had a 27 per cent cereal shortfall equivalent to about 223,487 tonnes,” he says. “This deficit, caused by the dual effects of drought and desert locusts, led to a 4.47million-tonne drop in food production.”
The situation is very worrying for Niger which is, with Mauritania, Mali and Chad, one of the so-called frontline states (a loose coalition of African states) in West and Central Africa. They are countries where outbreaks occur, the insects live on a permanent basis and can reproduce, forming swarms and invading crops — if the process is not interrupted.
In Niger, this happens in the regions of Aïr and Tamesna and, to a lesser degree, in the pastures in the Sahel, which is a summer reproduction area.
Fortunately, the country and the region do not face an invasion every year. “Over the past 30 years, there have only been three desert locust invasions: in 1988, 2003-5 and 2012,” says Moudy Mamane Sani, the director general of vegetable protection at Niger’s Ministry of Agriculture and Livestock.
However, the effects of these past invasions are felt for a long time. According to the CNLA, 1.25 million hectares of crops were destroyed in Niger during the 1988 invasion, which affected a total of 26 million hectares of crops in 23 countries
But this is not all. “Following the 2003-2005 crisis, nearly 4,000 villages in Niger were abandoned by residents who had lost their crops. This led to the exodus of these people from their villages to cities,” Moumouni says.
“Growers do not have anything but their production,” he says. “Where desert locusts go, they do not leave anything behind.”
He explains that growers who have lost their crops, and pastures that support their cattle, no longer have any capital; and all they can do is go to urban centres, look for a job and rebuild their lives until the following agricultural season.
However, for the residents of Bani Kosseye village, it is grasshoppers that are behind the distress, not a new invasion of desert locusts. “These are sedentary locusts which, unlike desert locusts, are not capable of gathering gregariously to form large swarms,” Maiga says.
Among these are Senegalese locusts, which Maiga says are particularly harmful for cereal crops, millet especially.
The fact of the matter is that grasshoppers also have a great capacity for harm in the fields. “Attacks by grasshoppers may take place at various stages of plant growth,” says Djibo Bagna, a farmer and the chairman of the executive board of Niger’s Farmers Platform.
“Once they have attacked seedlings, they move on to young plants. If they do not show up after seedlings have been attacked, it means they are waiting for plants to develop so they can attack leaves. [As a result] you will find stalks that are totally ‘naked’ and that will not yield anything at all,” he says.
“Grasshoppers even attack the ears [of cereal plants] and eat seeds which have not yet reached maturity. So you will see ears but there is almost nothing inside,” Bagna concludes.
This is more or less what the residents of Bani Kosseye experienced during the 2016 agricultural season. “Locusts appeared when the millet started flowering, both at heading time (when flower or seed heads start to show) and when seeds appeared,” says Issaka Arouna, a local farmer.
“We began fighting them even before the arrival of officials from the Ministry of Agriculture and Livestock,” Arouna says.
That particular fight was lost. It failed to prevent the risk of a food crisis, which is now dreaded in the village: “Can’t you see that empty granary over there,” says Arouna as he asks a young man to open one of the granaries of the village.
There is not much inside: ears of millet, some with sparse kernels, barely cover the floor area. “This is the crop of ten people you can see here,” the old man says with a stern expression.
This meagre crop is evidence that the threat of grasshoppers is far from negligible. “In fact, Senegalese locusts cause even more damage to millet in any one season than desert locusts do,” Idrissa Maiga says.
The species is particularly dangerous because it is endemic. “This is a situation we face on an almost yearly basis,” says Sani “During every agricultural season we are confronted with grasshoppers, and the seriousness of the situation varies from one season to another,” he says.
“This year, for instance, we have had many cases of grasshopper infestations, including in the Tilabéri, Zinder and Maradi regions,” Sani says.
Desperate times call for desperate measures — so countries which are most vulnerable to desert locust invasions have asked FAO (the UN’s Food and Agriculture Organisation) to coordinate prevention and response campaigns nationally, regionally and internationally. As a result, FAO has set up a special body in each region.
In Western and Northwestern Africa, which includes Niger, the body in question is the Commission for Controlling the Desert Locust in Western Africa (CLCPRO), which was set up in 2000. Each of its ten member states (Algeria, Burkina Faso, Chad, Libya, Mali, Morocco, Mauritania, Niger, Senegal and Tunisia) has pledged to set up on its territory a national desert locust control unit.
In Niger, the unit was set up in 2007. It is called the National Locust Control Center (CNLA), with headquarters in Niamey and a main operational base in Agadez, a city chosen for its proximity to outbreak areas.
“During remission periods, such as now, when there is no invasion and when locusts are in gregarious areas, the CNLA is tasked with leading monitoring operations,” Moumouni told SciDev.Net.
He says monitoring involves carrying out insecticide treatments as soon as the number of locusts reaches a certain level in order to confine them to gregarious areas.
“During invasions, the CNLA is tasked with preparing action plans as well as coordinating and evaluating response operations together with the Directorate for Plant Protection (DGPV) because we have limited means and personnel,” Moumouni says.
The directorate, part of the Ministry of Agriculture and Livestock, is also in charge of other types of locusts and pests, including grasshoppers.
Both bodies have opted for prevention as a strategy, spurred on by FAO which stated in 2006 that “when you look at the cost of response operations for the CLCPRO, you realise that expenses incurred to overcome the 2003-2005 invasion could have funded 170 years’ worth of prevention.”
Prevention is also driven by the economic, social and environmental impact of operations carried out as a result of the 2003/2005 invasion. “Thirteen million litres of pesticides were needed to overcome it. It cost more than half a billion dollars and caused crop losses worth more than $2.5 billion,” according to the FAO document.
Locust information network
As a result, steps are being taken in Niger to prevent invasions, and they involve both growers themselves as well as officials.
“We have growers whom we call brigadiers,” says Djbo Bagna, a farmer and the chairman of the executive board of Niger’s Farmers Platform. “We have already trained them to use pesticides and to alert technical services when the situation gets out of hand.”
“We have a locust information network,” adds the CNLA’s Moumouni. “For gregarious areas, we have trained nomads, the military and all community leaders so they can inform us as soon as they spot a locust.”
He says information is fed into the monitoring activities of the CNLA, which sends teams to these areas on a monthly basis to evaluate the situation before a decision can be made. The evaluation takes the weather into account, as it too affects the development and reproduction of locusts.
The presence of locusts does not necessarily mean that we will have to go and spray [pesticides],” he says. “There is an intervention threshold. As soon as there are 500 adult individuals or between 3,000 and 5,000 small larvae per hectare, an intervention is needed for numbers to come down.”
“The DGPV’s Sani says that “in the case of localised infestations over several hectares, growers themselves intervene quickly in their fields with portable sprayers to solve the problem.”
“When the situation reaches a certain threshold, it is a matter for decentralised services at local or regional level who have spraying machines fitted to vehicles and who can treat several hectares per day,” he explains. “Air operations are conducted when infestations reach several thousand hectares.”
Sani says Niger has an airbase with three agricultural aircraft to deal with large-scale infestations.
In addition to aircraft, biopesticide products have been designed to assist with the response. Green Muscle, for example, was developed by Chris Prior and David Greathead, two scientists with CABI (Centre for Agriculture and Biosciences International).
Neither Green Muscle nor any chemical pesticide will remove the threat. But with adequate monitoring of locust and grasshopper numbers — especially when they have just been born and before they become adults — Green Muscle may be able to control the number of locusts and grasshoppers, preventing them from becoming a threat for crops and human lives,” says Belinda Luke, a CABI biopesticide scientist.
The biopesticide is now sold by BASF but Luke says CABI is available to those needing advice to make the best use of the pesticide.
Monitoring and response
However, like those leading locust control in Niger, she believes monitoring remains the most effective weapon against desert locusts. “We need eyes in fields to monitor the number of locusts in order to be able to treat them with Green Muscle as soon as necessary.”
Meanwhile, research continues and Niger has the advantage of being the home of the Agrhymet Regional Centre, which was set up by the Permanent Inter-State Committee for Drought Control in the Sahel (CILSS) to “inform and provide training on food security, the fight against desertification and water management in the Sahel and Western Africa”.
Among other facilities, the Agrhymet Centre has an insectarium where locusts are raised for the purposes of scientific work. The institution was set up to serve the 13 member countries of the CILSS, but “offers Niger a benefit given that everything it develops as a decision support tool or any information it provides is first implemented in the nearest countries, i.e. in Niger,” says entomologist Maiga.
“It goes without saying that our cooperation with Niger’s national technical services in charge of the locust threat is much closer owing to this proximity,” he says.
Yet despite this mechanism, it does happen quite often that there is no immediate response when the alarm is raised. That is precisely what occurred in Bani Kosseye during the latest agricultural season. Locals are still reeling from the fact that technical services failed to intervene as soon as they raised the alarm.
Both the DGPV and the CNLA cite reasons to do with the unavailability of financial means, the procedure for making a military escort available for teams, and a shortage of staff in charge of monitoring and intervention in several places at the same time. These difficulties have given rise to the idea of using drones in the near future, in a bid to increase the efficiency of prevention and intervention operations.
Meanwhile, villagers are making do. “We have a traditional method whereby we light small fires around fields because locusts fly away when there is smoke,” says Arouna, from Bani Kosseye.
Unfortunately, this method was inadequate to protect crops during the 2016 agricultural season.
This article was originally published on SciDev.Net. Read the original article→
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