Biological control takes a food-chain approach to invasive plants
                                
                                
                                    (Newser) -
                                    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....