A new wave of locusts is threatening Africa with devastation and starvation, even as the COVID-19 pandemic undermines efforts to fight the locust plague. Parts of the continent already experienced the biggest locust outbreak in 70 years, just weeks before the coronavirus hit. Now a second wave is on its way, with some locust swarms 20 times the size of the first. Billions of young desert locusts are coming, threatening plants and crops. This second invasion includes more developed locusts known as “young adults,” which are especially voracious eaters. Some Africans view the locust swarms as more destructive than the...