The ‘Pocket-Sized Monster’ Terrifying Farmers the World Over

The fall armyworm is hungry, on the move and scaring farmers the world over. The crop-devouring pest has spread from the Americas to Africa and Asia, gorging on rice, corn, vegetables, cotton and more. Europe, Australia and Southeast Asia could be next. In its first three years in Africa alone, it inflicted $13.3 billion of crop losses. A recent arrival in China, the fast-moving grub may infest the country’s entire grain-producing farmland within a year. With food supply chains already facing disruption from the trade war and a global epidemic killing pigs, the world is bracing for the advance of what’s been called the “pocket-sized monster.”

It’s actually a caterpillar, not a worm. Fall armyworm (Spodoptera frugiperda) is native to the North and South American tropics and measures about 3-4 centimeters (1-1.5 inches). The grubs have a distinctive upside down Y on their heads and four dots on their second-to-last segment. They get their name from the way they advance en masse with military precision, feasting on the leaves and stems of some 186 plant species, including economically important crops such as wheat, soybeans and sugarcane.