Swarming in numbers not seen since the early 1950s, voracious grasshoppers have descended upon Florida's Pasco, Hernando and Hillsborough counties, near the center of the state's $1 billion-a-year citrus-growing industry. Already the insatiable insects have infested more than 10,000 acres of citrus groves, hayfields and pine forests. "The grasshoppers are so thick that the ground literally moves," says department of agriculture spokeswoman Michele McLawhorn.

For the moment, the bugs appear to be unstoppable: available pesticides last only a short time, and grasshopper swarms quickly move on. But recent rainstorms may help kill the invaders, and scientists hope to end the plague once and for all by bombarding the vulnerable grasshopper hatchlings with pesticides in the fall.