VIRUS RAVAGES cassava plants in Africa. Making life worse for some people whose lives don’t need to be worse. “After rice and wheat, cassava is the world’s third-largest source of calories. Under many names, including manioc, tapioca and yuca, it is eaten by 800 million people in Africa, South America and Asia. The danger has been likened to that of Phytophthora infestans, the blight that struck European potatoes in the 1840s, setting off a famine that killed perhaps a million people in Ireland and forced even more to emigrate.”