Farmers of decades past could lose entire seasons of crops to insects like rootworms, whiteflies, and aphids, but early solutions brought their own problems, like the pesticide-driven decimation of our bee populace. Researchers have explored other options, including modifying crops so they can help kill pests, but that backfired too. These engineered plants never slay all their targets because some invaders carry inborn resistance to the bug-harming proteins. Once the modified crop culls the rest of the swarm, those unpoisonable leftovers have only each other to make babies with. Presto: a new generation of better, badder creepy-crawlers. Researchers at the University of Arizona have gotten around this by planting unmodified seeds in genetically altered fields, which lets some nonresistant bugs survive and mix their susceptible DNA with their tougher buddies’. This method is labor intensive, though, so the Arizona group teamed up with some scientists in China to try crossbreeding. They bred altered cotton with an unmodified version, resulting in a variety that spawns a 75-25 mix of resistant to nonresistant plants.