Deploying drones to tackle desert locust swarms in East Africa
Earlier this year, the Horn of Africa witnessed a rapid rise in the number of Desert Locusts, described by the UN Food and Agriculture Organization (FAO) as “an extremely alarming and unprecedented threat to food security.” In Kenya, the locust swarms have been the worst infestation seen in 70 years.
As of the time of writing, Desert Locusts are still in East Africa. Ethiopia and Somalia continue to experience an unprecedented number of swarms. The situation, for now, in Kenya is relatively calm, but Dr George Ong’amo, Head of Insect Science, at the University of Nairobi believes they will return to Kenya in worrying numbers around mid-December. This new wave will affect areas in which individuals’ livelihoods have already been disrupted by earlier swarms, COVID-19, and, in some cases, floods. Where food insecurity is high, agricultural damage caused by swarms can lead to famine and mass-starvation.
The impact of desert locusts can be devastating to economic livelihoods; swarms of between 40 to 80 million locusts can roost in each square kilometre, and can eat the same amount of food in one day as 35,000 people. The causes of sporadic locust swarms of this magnitude are not fully understood, but it is widely believed to be linked to favourable climate conditions and compounded by limited ability to implement preventive measures in hard-to-reach breeding areas. Without intervention these plagues can last years before a natural die-off occurs.
The challenge the region is now facing is in implementing the most appropriate method to deal with these notorious Desert Locusts. Current locust control measures include a mix of ground spraying (with tractors, vehicle-mounted sprayers, or hand-held ULV sprayers) and aerial spraying. Whilst these methods are effective, there are disadvantages, ranging from potential environmental harm to the high costs entailed. Notably, aerial spraying is indiscriminate and can pose a danger to humans, ground spraying can also be dangerous to the operators, and is not always usable in hard to reach, unmotorable areas. Implementing drones, therefore, could potentially add value as a complementary technology to these other methods.
Deploying drones requires minimal personnel compared to ground sprayers, and can even incorporate swarm intelligence to allow for multiple drones to operate in formation. Drones present an opportunity to enhance current control strategies as they can reach areas ground spraying cannot reach and target small swarms, which might not make economic sense to spray with an airplane. Other possible advantages we are hoping to explore include, their use next to inhabited areas, and at night, both scenarios where the use of airplanes can be problematic.
However, before we can advocate the use of drones, it is essential we gather enough data on their effectiveness, efficiency and safety. In a recent side event at the World Food Prize, Keith Cressman, Senior Locust Forecasting Officer for the FAO, discussing the topic of drones for locust control highlighted the fact that ‘we are dealing with poisons …and the margin of error is very tight’. Much like in medicine with a drug, any new delivery mechanism has to be tested and understood before being adapted more widely.
The choice of pesticide is also something we are looking to explore. The reality is anything that kills locust quickly is likely to be toxic to beneficial insects, such as bees and even humans. We are hoping that drones will be compatible with some of the safer pesticides in use, and are keen to explore drones as a delivery mechanism for Metarhizium (a fungal biopesticide which has great specificity to locusts and is relatively harmless to other species).
To answer these questions, the Frontier Technologies Livestreaming (FTL) Programme has partnered with Astral Aerial Solutions to pilot the effectiveness of drones as a complementary technology in tackling the desert locust problem in East Africa. Aiding the pilot with expert entomological advice is Dr Ivan Rwomushana from CABI a Senior Scientist specialising in invasive species management, and Violet Ochieng from the University of Nairobi.
The pilot is taking place in Kenya, and the first sprint has already kicked off with the team in the field collecting baseline data on the drones range, and the efficacy of the pesticides. Further sprints will optimise parameters such as height and speed, as well as explore different pesticide formulations. It is our hope that the data produced by this pilot will form a foundational knowledge base that will be useful in the fight against locusts globally.
