HONG KONG—Swarms of desert locusts have devastated crops in East Africa, hit the Middle East and moved into South Asia. They’re breeding fast thanks to changes in global climate patterns that have brought about major cyclones and heavy rains, and they are feeding off human food supplies across continents.

So far, India has managed to prevent a swarm of biblical proportions from spilling over into Bangladesh, Burma, and then China—where the coronavirus has already paralyzed much of the country’s activity. But it’s not clear how long that line will hold.

Eastern Africa has been hit the hardest by the xanthic bugs, with fields in Tanzania, Kenya, Uganda, South Sudan, Ethiopia, Eritrea, and Somalia ravaged by 360 billion locusts. Swarms can be city-sized, and one of the largest—located in Kenya—covers about 37 miles by 25 miles. It is so dense that it turns daylight to darkness for anyone caught within.

Alarmist headlines are proliferating, too, many of them drawing parallels with the plagues in scripture. “Bible coming to life?” asked the Jerusalem Post. The swarms appear in the Old Testament, most notably in Exodus as one of the plagues Moses calls down on Egypt, which also is referenced in the Quran. In the New Testament locusts are associated with Revelation 9:3, where they emerge in ferocious swarms that also have the sting of scorpions.

Allusions to the Apocalypse aside, the real life potential for disaster is huge.

A square mile of a swarm can be formed by up to 210 million locusts, which can eat as much food as 90,000 people in a day. In East Africa, the bugs have been tearing through maize, sorghum, cowpeas, as well as vegetation that cattle graze on.

Kenya hasn’t seen a swarm this size in seven decades, while Ethiopia and Somalia have managed to avoid these conditions for a quarter of a century. The governments of Kenya and Ethiopia have each dispatched several planes to dump pesticides from the air, which the United Nations’ Food and Agriculture Organization (FAO) says is the only effective way to kill desert locusts. Farmers attempt to chase the bugs off, blasting the claxons on their motorbikes, or rigging contraptions that make loud, metallic noises when shaken. These methods have not made a dent in the locust population. There are simply too many of them.

The FAO calls locusts the “most dangerous migratory pest.” They are highly mobile, able to travel up to 90 miles a day if wind conditions are in their favor, and wreak havoc along the way. Female locusts can lay up to 300 eggs within their life span of three to five months. As many as 1,000 egg pods, each holding up to 80 eggs, can incubate underground within a square meter (10.7 square feet).

In the past, desert locusts have been a key factor that aggravated famines in Ethiopia. And in 1915, they stripped Ottoman-era Palestine of nearly all vegetation.

Nowadays, desert locusts are still hard to control, chiefly because they tend to breed and thrive in large swathes of remote land, making it difficult for authorities to tackle the problem before it emerges. The countries that are most severely affected also tend to have weaker infrastructure, making them slower to move the necessary supplies and information to parties that need them.

In the East African countries where locusts are swarming now, 20 million people already face food insecurity.

The bugs multiplied and some swarms went north to Egypt, threatening a nation where food insecurity is a massive concern, particularly outside of the capital and major cities. (Headline in British tabloid The Express: “‘We are in the last days’ Locust swarm approaching Egypt sparks Bible apocalypse fears.”)

But most swarms crossed the Red Sea and made their way to Western Asia, chewing through Saudi Arabia, Yemen, and Iran in early January and laying more eggs along the way.

The Middle Eastern nations’ pest control operations failed to cull the locusts, so beds of eggs will hatch by mid-March, releasing new hungry bugs.

“ Global Times has been offering ludicrous consolation to the public, claiming that the desert locusts are 'eaten by ducks, fried for food.' ”

In the first two weeks of this year, fields in Pakistan and India came under attack too, the swarms intensifying day after day. In India’s Rajasthan and Gujarat—two states in the country’s northwestern quadrant that share borders with Pakistan—more than 380,000 hectares of farmland have been damaged. The season’s harvest of mustard, cumin, and wheat has been consumed by the swarm.

What makes the current surge of locusts stand out is not only their numbers and intensity, but also that they are active in the subcontinent during winter months. In the past, swarms typically would dissipate by October. Now it’s February, and they are still going strong.

The Indian government was quick to identify the locusts as a major problem, and dispatched experts to work with their counterparts from the FAO in the affected regions. They’re tracking the swarms and destroying beds of locust eggs to limit the bugs’ propagation. And the government has diverted $4.3 million as compensation for farmers who have lost their crops.

For now, the Himalayan range is acting as a natural barrier for China, insulating its southwestern border from the scourge that is in Pakistan. But the locusts could bank into Southeast Asia, flowing through Bangladesh and up into Burma, landing in China’s Yunnan province, hitting a country that is already locked down because of the coronavirus’ rapid spread.

As fears rise, the state-run media outlet Global Times has been offering ludicrous consolation to the public, claiming that the desert locusts are “eaten by ducks, fried for food,” and “not a threat to China.” And the international arm of state-run CCTV even released a bizarre video of “duck troops” amassing at the border. But the species of locust that is on the country’s doorstep emits phenylacetonitrile, a foul-smelling secretion that is meant to deter predators. Birds typically do not seek them out as a food source.

Spokespersons for China’s Ministry of Agriculture and Rural Affairs claim that there is a “very low risk” of locust plagues hitting China, but a researcher at the Beijing-headquartered Institute of Plant Protection of the Chinese Academy of Agricultural Sciences suggests more caution.

The agriculture expert, Zhang Zehua, said that Yunnan province (which borders Burma), Guangxi (an autonomous region east of Yunnan), and Sichuan province (north of Yunnan) could be affected in June or July if the plagues are not brought under control in neighboring countries.

Zhang may be right, at least according to India’s Ministry of Agriculture, which issued a notice saying that it expects 200,000 square kilometers (77,200 square miles) of farmland to be blanketed by locusts in June during the onset of monsoon season—when conditions are perfect for ravenous insects to breed.

For now, whether the summer may bring another catastrophe to China depends chiefly on Delhi and Karachi’s efforts to exterminate a storm of insects in a race against the seasons.