New Delhi, June 14 -- The New World screwworm is back in the United States for the first time since 1966, and it has arrived at the worst possible moment for an administration that spent the past year hollowing out the agency meant to stop it. A flesh-eating parasite that lays its eggs in the open wounds of living animals has crossed into Texas after a yearlong march north through Central America and Mexico. The Trump administration insists it is ready. The numbers it spent a year producing tell a less reassuring story.

three calves and a goat in Texas and a dog across the line in Lea County, New Mexico. As ABC News reported, the Department of Agriculture moved quickly once the infestations were found, drawing a twelve-mile quarantine zo...