Officials in the Midwest are returning to a tried-and-true technique to fight invasive plants, the Chicago Tribune reports. Biological control uses natural enemies to rein in pests, and importing a tiny brown beetle in the 1990s brought under control a fast-spreading European weed, known as loosestrife, that was terrorizing agriculture. There are other enemies now—but scientists worry the approach could create other problems.
It's possible the insects will find indigenous plants tasty, too, or will lose their appetite for the target species. "There's always that apprehension: Things are great now, but what will things be like in the future?" says an Illinois ecologist. "Will something we bring in now haunt us down the road?"