After rainfall in the swathes of desert from West Africa to India, plants begin to grow and desert locusts scuttle to their newfound food supply. As the solitary insects congregate to eat what little vegetation is available, they can quickly turn into dangerous and destructive plagues.
To prevent these small groups from becoming crop-consuming swarms that black out the horizon and devastate national food supplies, scientists observe vegetation growth, track locust movements and population and spray pesticides to avert disaster.
Desert locusts inhabit about 20 per cent of the earth’s land surface. Preventing swarms in this massive tract of arid land seems nearly impossible, but modern science has revolutionized how the locusts are monitored and treated, and drones are the newest technological addition to the world’s locust-fighting arsenal.
The UN’s Food and Agriculture Organization (FAO), which is tasked with monitoring desert locusts, has partnered with HEMAV, a civil society drone technology company, to integrate drone technology in locust prevention and treatment.
The four year development plan, which started in 2016, culminates at the end of 2019 with the dispatch of drone sets to most of the 30 countries that deal with desert locusts.
According to the HEMAV website, the drones will be equipped with high definition visual sensors and thermal cameras. They can map potential outbreak areas and monitor vegetation and groups of gathering locusts.
Without careful monitoring, those seemingly harmless groups can turn into “carpets of nymphs that march across the desert and these swarms of adults that look like clouds and block out the sun,” Keith Cressman, FAO’s senior locust forecasting officer, told The National.
Mr Cressman says the desert insect’s ravenous appetite makes it one of the most dangerous locust species on the planet.
They migrate from the desert in towards habitable land, devouring any vegetation in their path. A swarm the size of Rome - a relatively small swarm, he says - can eat the same amount of food as half of Italy’s population in one day.
“If they can find these concentrations and treat them, then we prevent the swarms from forming and we prevent plagues from occurring,” he said.
Methods for tracking and treating locusts have developed significantly since the FAO started monitoring the insects in the 1950s.
“In the past, they used to look for locusts on camel in the desert, and they used to write the information down in a note or letter that they would eventually send to the capital or to Rome and it would get here two or three months later,” Mr Cressman said.
Four-wheel drive vehicles have since replaced the camels, and GPS units, digital data loggers and satellites took over for the handwritten snail mail. Now, ground teams can send locust data in real time to their national office and FAO’s headquarters in Rome.
But satellite imagery is often untimely and low quality. Aerial surveys are costly and out of the question for poorer countries. Although vehicles have boosted the range of ground teams, increasingly unsafe conditions in many of the frontline countries have hampered prevention efforts.
Drones transmit their data instantly, cutting back on wait times. They are not only much more affordable than helicopters and airplanes, but drones also have the advantage of being unmanned.
If an outbreak is imminent or has already turned into a swarm, drones can be fitted with bio and chemical pesticides. Mechanical spraying is more precise, timely and efficient, but it’s also a safer option for humans.
“It would take the danger of using pesticides out of human hands and into the drone, so this would be much safer for the applicators and the people involved in control operations,” Mr Cressman said in an interview with HEMAV.
“We hope that the use of drones would make the monitoring of the locusts, which is so important for early warning, to be much more efficient and much more effective.”