New Israeli research reveals decision-making mechanisms in locust swarms and combines food security with the development of autonomous drones
The locust plague, the eighth of the ten plagues recounted in the Passover Haggadah, remains one of the most serious threats to global agriculture. Locust is a collective name for several species of grasshoppers that gather in swarms and migrate together. A locust swarm can contain billions of individuals, travel hundreds of kilometers in a day with the wind, and wipe out entire fields of crops in a matter of hours. Behind the locust's destructive behavior lies a biological phenomenon that raises the question: How do locusts know how to move together, in a remarkably coordinated manner, without having a clear leader? study A new Israeli reveals how locusts make decisions in collective movement, and why this understanding could affect the future of technology.
Control the swarm
Locust swarms are a serious threat to food security in many countries, mainly located in Africa, the Middle East and South Asia. According to data from Food and Agriculture Organization According to the United Nations, the major desert locust outbreak in 2020–2021 was one of the most severe in recent decades. During this period, approximately 23 million dunams of areas containing locust swarms were treated. The main method of treatment is by spraying pesticides from aircraft and directly on the ground. The control is carried out before the locust swarm arrives and while it is active in the field. Thanks to the treatment, an estimated loss of 4.5 million tons of crops was avoided and the food security of approximately 41.5 million people was maintained. The economic damage avoided was estimated at approximately $1.77 billion.
There was also a sense of alertness in our country.2021 Locust invasions have been documented in the Arava and the Negev.2013 Swarms crossed the border from Sinai, matured, mated, and laid eggs in the Negev, which required extensive pest control operations. In 2004, swarms reached Eilat and the Arava, but disappeared within a few days without causing significant damage. Similar events also occurred in the 50s and 60s. "The locust phenomenon cannot be completely stopped, but we can learn from it about the swarm phenomenon in the best possible way," says Prof. Amir Ily of the School of Zoology at Tel Aviv University and the Steinhardt Museum of Natural History. In other words, it is important to try to stop the phenomenon in order to prevent the formation of swarms. When a locust swarm moves, it may seem as if it is guided by external forces. But in fact, each individual makes independent decisions based on the stimuli it perceives from its environment. The research team tried to understand what stimuli cause individuals in the locust to change direction, and how this affects the entire swarm.
Like driving a car
To study swarm movement, the research team showed individual locusts in a swarm images of movement that simulate swarm movement. They varied the speed of the images to understand which parameters cause changes in behavior. Through simulations and in-depth analysis, the researchers found that locust movement is based primarily on vision. When an individual locust sees its neighbors moving in a certain direction, it tends to adjust its direction to theirs. But it's not that simple: "Locusts don't have 'leaders' within the swarm that influence everyone's direction," explains Eli. According to him, the swarm's movement and behavior are dictated and result from local interactions between individuals.
One of the fascinating discoveries is the behavior of locusts during their movement. The research team noticed that individuals tend to stop for very short periods of time during their movement and then continue moving. By measuring the duration of the stops and examining the relationship to the angle of vision of the individuals, it can be concluded that these stops are a critical stage in the decision-making of the entire swarm. “The observations showed that these short stops are actually moments of information processing,” explains Ily. “The locust scans its surroundings, examines the direction of movement of others, and then makes a decision on how to proceed – just like a driver who slows down for a moment to check the road before continuing to drive,” he says.
The future of swarm research
Understanding the movement of locust swarms could have implications not only for agriculture, but also for aviation and artificial intelligence. Eli explains how the insights gained from locust decision-making mechanisms could serve as a basis for developing advanced robotic swarm systems. For example, the US military and leading technology companies are working on developing autonomous drones that operate without central control, based on shared decision-making between the different units – like in the locust swarm.
The current study is just the tip of the iceberg. There are studies currently exploring how these findings can be used to create more accurate models for predicting locust movement. In addition, there is growing interest in finding ways to disrupt the swarm's decision-making, so that it can be made to change direction proactively.
So the next time you hear about swarms of locusts invading agricultural fields, remember: this is not just an agricultural disaster but also a fascinating phenomenon that could change the way we understand collective movement in nature and technology.
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