At least 20 million people are in danger as scientists and governments rush to bring the insects under control.
Locust swarms sweep the 'cradle of civilization'
The outbreak today coincides with cyclones in 2018, and the warm weather at the end of 2019, compounded by unseasonably heavy rains. Scientists detected vast swarms at the beginning of 2020 in Somalia and Ethiopia, and afterward they insects spread wild across countries like Kenya — where they've been a constant plague-like presence for 70 years — Sudan and Uganda. Swarms were also detected in Saudi Arabia, Iran, Pakistan, and India.
Previously, Kenya saw an incredibly large swarm occupy an area of 2,400 square kilometers (926 square miles), more than three times the size of New York City. A swarm of locusts typically occupies 100 square kilometers, but even at this smaller size, between 4 and 8 billion locusts are flying and buzzing around inside, collectively capable of eating the equivalent of what 3.5 million people can eat in a single day.
The swarm could even spread as far north as Turkey, according to the country's Head of Chamber of Agricultural Engineers, Özden Güngör.
The United Nations' Food and Agriculture Organization (FAO) has appealed for US$138 million in immediate funding. Meanwhile, researchers have stressed the need for better monitoring to predict insect movement and growth, adding that alternatives to synthetic chemical pesticides are necessary to attack locust populations before they breed into an even larger swarm.
Locust population explodes
The desert locust — also known by its scientific name, Schistocerca gregaria — is found in more than 65 of the world's countries, and doesn't normally join into large swarms in the deserts that stretch from West Africa to India. Locusts breed following periods of rainfall, when soil is moist — ideal for locusts to lay eggs. But when it pours rain, locust populations build up incredibly fast, into vast, maddening swarms.
Additional swarm factors
There are of course other factors in play, said Director-General Segenet Kelemu of the International Centre of Insect Physiology and Ecology in Nairobi, which has advised the Kenyan government on control measures. For example, continuing war and violence in the region has made much of Yemen inaccessible to research workers and humanitarians, slowing the world's ability to combat outbreaks.
"Swarms also develop when control efforts break down or political or natural disasters prevent access to breeding areas, and interventions do not start early enough," Kelemu said, to Nature. "Countries like Yemen, where there are human catastrophic situations due to conflict, are in no position to take care of invasive pests."