Desert locust

Alone it is calm, in a swarm it is a storm

A lone locust is green and shy. But after rains, when there are many and they bump into each other, they turn yellow and black and form a giant swarm — millions of insects darken the sky! Such a swarm eats as much food in a day as a whole city. People have feared it since ancient times. Uzbekistan has locusts too, but the desert locust lives in Africa.

The desert locust (Schistocerca gregaria) is the most dangerous pest of Africa, the Middle East and South-West Asia. It has two 'phases': solitary (green, calm) and gregarious (yellow-black, active) — as density rises, touching of the hind legs releases serotonin and changes behaviour within 2 hours. A swarm holds 40–80 million per km², flies 150 km a day and eats its own weight (2 g) in plants — a 1 km² swarm destroys food for 35,000 people. The 2019–2021 upsurge in East Africa and India was the worst in 25 years. FAO forecasts it with satellite and rainfall data. Uzbekistan has Moroccan and Italian locusts, monitored in Kashkadarya and Surkhandarya.

Fun facts

• A swarm holds up to 80 million locusts per km² and flies 150 km a day.
• A lone locust joining a swarm changes colour and behaviour in 2 hours.
• One swarm eats the food of 35,000 people in a day.