The scientists came up with the idea after discovering the evil weevil is quite rare in some regions of Central America--even though that's the neighborhood of its origin. Working with counterparts in Honduras, they learned that female flies scout out plants that are infected with weevils. The flies then give birth to live larvae, which attack the weevil larvae, killing them in their most destructive phase. "The moms know how to distinguish sick bromeliads, and they put the larvae right on them," explains Howard Frank, a professor of food and agricultural sciences at the University of Florida, and the man for whom the fly is named. The critters don't go after beneficial bugs. And they don't do any harm on their own. This month, the researchers announced that flies from an earlier release survived, reproduced, and were continuing to perform their jobs. Better materials are the key to lighter vehicles that burn less fuel. Scientists at the University of Michigan have borrowed a trick from oysters, which fabricate mother-of-pearl one layer at a time, and have used it to make a tough, superlight composite plastic. The researchers started with a layer of clay only nanometers thick, then added a sticky liquid, then another layer of clay--repeating this process 300 times. The result is a light, transparent substance as strong as steel but no thicker than plastic wrap.Taking a different tack, San Diego's CellTech Metals is making more durable sheet metal that resembles corrugated cardboard. On the outside are thin steel layers. Sandwiched in between is a rippled layer created by crinkling steel into waves. The resulting product is the same thickness as sheet metal, but half the weight and more than three times as strong. It could be cheaper and better than aluminum in automobile hoods, fenders, and other parts, says CellTech CEO Doug Cox.