Our new model shows locusts making sophisticated judgments in deadly swarms

Locust Swarm Behavior and Climate Change

• Locusts, grasshoppers, multiply rapidly and change color in response to their environment.

• In gregarisation, they transition from solitary creatures to swarms, congregating in large numbers and travelling together over several leagues at a time.

• These ‘outbreaks’ have led to widespread famine and economic devastation, earning them the name “locust plagues.”

• In late 2019, a wave of billions of desert locusts flew into western India through Pakistan, causing over two lakh hectares of crops to be destroyed.

• Researchers from German and North American universities studied locust swarms in Kenya to refine a longstanding theory about swarming behaviour.

• Previous models of locust swarms have treated them like gases in motion, assuming individual locusts aligned with their neighbours like self-propelled particles.

• A revised model proposed by Iain Couzin and his team suggests locusts don’t behave like gases but follow a cognitive decision-making process based on their perception of nearby motion.

• The study led to the development of a new mathematical model based on a neural ring attractor network, addressing locusts as decision-making entities that could integrate multiple visual inputs before choosing a direction.

• The model suggests locusts may weigh different potential options and make effective decisions, but at the group level, there’s no planning at all.

• The study established how swarms move and how coordinated motion arises, but the initial direction selection and how this is maintained remain unclear.

• Climate change has worsened the problem by increasing rainfall in desert regions, creating ideal breeding conditions.

• The study calls for more research and involvement of climate scientists and vegetation experts to better understand and predict locust swarms.