The News: News reports over the past few months have spotlighted huge swarms of desert locusts occupying an area the size of New York City or Paris! These locusts have eaten and damaged crops across countries like Kenya, the Democratic Republic of the Congo, Iran and Pakistan, and they are now in India.
So what are locusts and why are they notorious?
Locusts are insects that are related to and look like ordinary grasshoppers. The desert locust is an infamous species found in Africa, the Middle East, and Asia.
They usually lead shy, lonely lives but their behaviour changes during hot dry spells of weather. During this time they are forced to feed together on small patches of green vegetation and this interaction causes their bodies to release a chemical called serotonin. This transforms them from loners into very sociable or gregarious creatures.
When they are in their gregarious phase they swarm together in large numbers. Their brains grow bigger, they move faster, and they have larger appetites. A typical swarm can pack between 40 and 80 million locusts and they can consume the same amount of food in a day as 35,000 people can! While the insects do not harm humans or animals, they can cause significant damage to crops.
These massive swarms travel very fast and spread across entire regions gobbling up crops and ravaging agriculture in their wake. If uncontrolled, they damage food supplies and can cause food shortages, and in extreme situations, even famines.
So what is happening in India?
India is experiencing the biggest desert locust invasion in nearly thirty years. Locust invasions in some parts of Rajasthan close to the border with Pakistan are a regular phenomenon, but this year the swarms are larger and have migrated earlier. The swarms contain up to 40 million insects and have hit Rajasthan on 11 April. They have also affected at least five other states in India.
Luckily, in India there are no crops in the fields yet but the swarms are eating any green vegetation, leaves, flowers, fruits, seeds and plants in sight. They are traveling fast, sometimes up to 400km (248 miles) in a day and supposedly heading towards Punjab and Haryana.
The government and farmers are working together to control these swarms using pesticides. They are spraying chemicals across large areas using planes, drones and tractors to kill these insects.
Why are these swarms bigger than before?
Warm weather followed by unusually heavy rains provides the right breeding conditions for locusts. According to the UN, climate change caused heavy rains and cyclones in East Africa in December 2019 and caused the locust population to explode! Though the swarms originated from there they have found multiple breeding grounds on the way.
Did you know?
Locust swarms can cover long distances and stay in the air for long periods of time. They regularly take nonstop trips across the Red Sea between Africa and Saudi Arabia. In 1954, a swarm flew from northwest Africa to Great Britain, while in 1988, another made the lengthy trek from West Africa to the Caribbean, a trip of more than 3,100 miles in just 10 days.