What Are Locusts and Why Do They Swarm?
Locusts are grasshoppers that can change behaviour and form massive swarms under certain conditions.
This change, called gregarisation, causes them to group, grow bigger, and travel together.
Historically, locust swarms have caused famines and crop loss, known as locust plagues.
The 2019–2022 outbreak was the worst in decades, destroying over two lakh hectares of crops in countries like India, Kenya, and Ethiopia.
New Discoveries About Swarm Behaviour
Scientists used tracking and virtual reality to study swarms in Kenya.
They found that vision, not touch or smell, guides how locusts align and move in swarms.
Locusts move based on coherence of motion — they follow others' direction, even in less crowded groups.
A new neural-based model shows that locusts make simple decisions based on what they see, not like gas particles as older models suggested.
How Locust Swarms Form and Move
Each locust decides how to move based on nearby motion, not by following a leader.
This is an emergent behaviour, where large group patterns form from simple individual actions.
Similar behaviour is seen in bird flocks and traffic flow.
The Role of Climate Change
Climate change is making swarms worse by causing more rain and stronger cyclones in deserts.
The 2019–2022 swarm was worsened by heavy monsoons and delayed control efforts.
Experts say better tracking and updated models are needed to predict future swarms.
More research is needed, involving climate and plant experts, to prepare for more frequent and unpredictable outbreaks.
COMMENTS