What Is the Locust Attack All About?
The term “locust attack” refers to the rapid, large-scale invasion of farmlands by swarms of desert locusts, which can cause devastating damage to crops and vegetation. These attacks often follow unusually favourable climatic conditions (such as extended rainfall), which allow locusts to multiply quickly and gather into enormous swarms.
The 2019–2022 locust crisis is a prominent example, where countries like Kenya, Ethiopia, Somalia, Pakistan, and India faced the worst outbreaks in decades. The swarms destroyed hundreds of thousands of hectares of crops, threatening food security and livelihoods across large parts of Africa and Asia.
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## 2. What Are Desert Locusts?
### Species Overview
– Scientific Name: *Schistocerca gregaria*
– Classification: Insect species belonging to the grasshopper family
– Habitat: Primarily found in semi-arid and arid regions of Africa, the Middle East, and South Asia.
### Breeding Needs
– Require bare ground (typical of desert areas) for laying eggs.
– Thrive in areas where **rainfall temporarily boosts vegetation**—ideal for feeding and reproduction.
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## 3. How Do Desert Locusts Form Swarms?
### Solitary Phase
– Locusts live and move independently in low-density populations.
– In this phase, they are harmless and behave like typical grasshoppers.
### Gregarisation Process
When environmental conditions (e.g., **sufficient rainfall, green vegetation**) are favourable:
1. Locusts begin to crowd together.
2. Physical and chemical signals trigger behavioural and physical changes.
3. They transform into a gregarious phase — becoming highly mobile, social, and aggressive.
This transformation is known as gregarisation, which includes:
– Colour change (often turning yellow or pink)
– Increase in size
– Behavioral changes that encourage group formation
### Swarms Formation
– In this gregarious phase, locusts aggregate into swarms.
– A single swarm can contain 40–80 million locusts per square kilometre.
– Swarms can travel up to 150 km per day, devouring everything green in their path.
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## 4. Population Explosion Potential
– Ideal breeding conditions (such as back-to-back rains or cyclones) allow for rapid reproduction.
– A single swarm, if left unchecked, can multiply its population 20-fold in one generation.
– Subsequent generations can exponentially increase the swarm size, making it harder to control.
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## 5. Why Are Swarms Dangerous?
– Crop destruction: A large swarm can eat as much food in one day as 35,000 people.
– Livelihood threat: Rural farmers and pastoral communities are most vulnerable.
– Food security risk: Entire regions can face famine or food shortages.
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## 6. Summary
Desert locusts are a natural part of the ecosystem in arid regions but become a serious threat when triggered into swarm behaviour by favourable weather conditions. Understanding their lifecycle and behavioural shifts is crucial for predicting and controlling outbreaks to prevent agricultural disasters.
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