Portrait of a locust campaign
Teamwork and technology, seven days a week
Nouakchott, Mauritania - Desert locust survey and control missions take place across West and Northwest Africa, but the story really begins deep in the Sahara in this vast arid country.
In September 2003, the National Centre for Locust Control sent a two-vehicle team on a routine 3 500-kilometre survey into the centre and south - traditional locust breeding areas. This time they found something.
"We began seeing desert locusts every 100 metres where there had been only a few the month before," recalls Mohamed Lemine, an FAO locust expert based in Mauritania. "I reported that there was good potential for an outbreak."
His report was shared routinely with neighbouring countries and the Locust Group at FAO headquarters in Rome.
"I treated the report with caution since such breeding patterns have been known to fizzle out," says FAO Locust Forecasting Officer Keith Cressman. "Then in mid-October we got reports of exceptionally heavy rains in the western Sahara and I knew we were in for it."
On 17 October, FAO issued a desert locust alert, followed quickly by field missions to Mali and Mauritania.
On the northern side of the Sahara, in countries such as Morocco, officials mobilized rapidly.
"We started getting information on activities from September, an improvement on the 1988 locust plague, when FAO was late warning us of activities," says Abdelaziz Arifi, senior adviser on locusts to the Moroccan Ministry of Agriculture and Rural Development. "We reacted early. We checked our stores of pesticides, rented planes, contacted donors and alerted the Government, which won't act until they actually see the locusts. It is critical to hit the locusts fast before they start reproducing."
Early warning has improved since the 1980s. Many of the affected countries now conduct more frequent and methodical surveys of locust breeding grounds and share their findings more widely using the latest communication technology. The science of locust forecasting is more sophisticated as well. (See "New ways to tackle locusts" in related stories at right.)
But once a control operation gets under way, the marching orders are simple: find as many locust as possible and kill them.
"When we survey, we will follow a swarm even in the dark until it settles," says Jacob Habab, a survey officer in Mauritania. "I use a GPS [global positioning system] to determine the latitude and longitude of each corner of the infested area, then radio headquarters with the report. Sometimes we treat the locust with vehicle-mounted sprayers, but you need planes to treat big areas."
Mr Habab bends down to dig in the sandy soil in the countryside near Kaedi, southern Mauritania. "You see that it is moist. It is good for egg laying and we know that in 10 to 15 days we have to come back and check if the locusts have returned to lay their eggs."
In Mauritania, survey missions are self-contained, travelling for weeks in four-wheel-drive vehicles packed with camping equipment, fuel, food and water. In Morocco, survey crews live in camps, inspecting a set area and returning to camp to radio in reports and spend the night.
Pesticide and planes
Pesticide handling and logistics are one of the trickier elements of a big control operation. Although research into more environmentally friendly pesticides and biocontrol agents is ongoing (see "New ways to tackle locusts" in related stories at right), organophosphate pesticides remain for the moment the only way to treat large infestations of locusts. In Morocco, once survey reports have pinpointed the next day's targets, pesticides are dispatched day and night from a warehouse on the Atlantic coast near Agadir. Trucks roll all night to arrive at airfields before first light, when planes will be loaded and take off to spray the insects at dawn.
"We order pesticide delivered by ship from the manufacturer in Europe on an as-needed basis. We do it this way to avoid having leftover pesticides at the end of the campaign, which can then become obsolete and a big headache to get rid of," says Ahmed Mouhim, assistant director of the National Centre for Locust Control.
Mr Mouhim hasn't seen his family in Agadir for months. He has been in Bouarfa on the far side of the country, teaching 20 local technicians how to conduct surveys.
This morning, spray planes from Spain are prepared for takeoff, a mechanic calibrating the spray heads while the pilot enters target coordinates into the onboard GPS. The plane will be flying low this morning, 10 metres off the ground, back and forth over a 60-square-kilometre infestation.
The fine spray - one litre of pesticide covers one hectare - leaves the locusts intoxicated and flying erratically close to the ground. They die within 24 to 48 hours. The vegetation or crops that remain will be safe again for livestock in seven to ten days and humans in two weeks.
Back at the airstrip, pesticide handlers and air crews line up for a regular blood test for pesticide poisoning. One worker has a reading that is a bit high. He is given ten days off with pay, enough time for the reading to return to normal.
In Bouarfa, as elsewhere in the locust-affected countries, the day's spraying is done and operations pass back to the survey teams to find new targets to treat in a campaign that never sleeps.
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