Locusts have been feared and revered throughout history. Related to grasshoppers, these insects form enormous swarms that spread across regions, devouring crops and leaving serious agricultural damage in their wake. Locusts can become gregarious at any point in their lifecycle.
Source: National Geography
As their name suggests, desert locusts normally live and breed in semi-arid/desert regions. For laying eggs, they require bare ground, which is rarely found in areas with dense vegetation. So, they are more likely to breed in Rajasthan than in the Indo-Gangetic plains or Godavari and Cauvery delta.
Locusts aren’t dangerous as long as they are individual hoppers/moths or small isolated groups of insects, in what is called the “solitary phase”. It is when their population grows to large numbers – the resultant crowding induces behavioral changes and transformation from the “solitary” to “gregarious” phase – that they start forming swarms.
Source: The Indian Express
Grasshoppers, or hoppers, are solitary creatures that don’t live in groups. But if driven by hunger caused by drought or food scarcity, they start to gather together while foraging for food.
As their population increases in an area, they start becoming “gregarious”.
In ecology, gregariousness is the tendency of animals to form social groups to hunt or eat together. It tends to induce hoppers to start coordinating their movements and form swarms. Gregarious hoppers are referred to as locusts.
Source: The Print
What countries are affected by the Desert Locust?
During quiet periods (known as recessions) Desert Locusts are usually restricted to the semi-arid and arid deserts of Africa, the Near East and South-West Asia that receive less than 200 mm of rain annually. This is an area of about 16 million square kilometres, consisting of about 30 countries.
During plagues, Desert Locusts may spread over an enormous area of some 29 million square kilometres, extending over or into parts of 60 countries. This is more than 20% of the total land surface of the world. During plagues, the Desert Locust has the potential to damage the livelihood of a tenth of the world’s population.
Current Deep Invasion Of Locusts
Current deep invasion of locusts has been caused by the low availability of crops in the region. It leads to the swarms devouring leaves on trees, and vegetable, fruit and cotton crops, and move deeper into India in search of fodder.
The swarm that is currently attacking India and other nations has its roots in heavy cyclones and rainfall over the past two years, a trend that has been attributed to climate change.
India has offered assistance to both Pakistan and Iran to jointly combat the locust menace. However, only Iran has accepted the offer so far.
Locust Warning And Control Organisation (LWO)
India also has a locust warning and control organisation (LWO), formed in 1939 and overseen by the Indian Council of Agricultural Research.
The LWO monitors locust scenarios over desert areas. It has two headquarters, one in Faridabad (near New Delhi) for administrative duties and one in Jodhpur (Rajasthan) for technical operations.