The Parasite at the Gate: Why the Return of the New World Screwworm Has U.S. Agriculture on Edge
By Sentel Why this matters: A flesh-eating parasite once eliminated from the United States has been confirmed again in parts of Mexico—closer than it has been in decades. It may sound distant, but history shows this insect can disrupt food supplies, raise grocery prices, and test our public-health defenses if vigilance slips. At dawn, the pasture looks calm. Dew clings to the grass. A veterinarian bends to examine what seems like a routine wound on a farm animal—until movement appears where there should be none. Tiny larvae twist inside living tissue, feeding aggressively. It is the kind of sight many professionals in North America have only seen in textbooks. Yet this is real, and it has a name with a long memory: the New World screwworm. The screwworm is not just another fly. Its larvae don’t wait for decay. They eat healthy, living flesh. Untreated, a single wound can become fatal within days. For decades, this parasite haunted ranches across the southern United States, inflictin...