Spotted-wing drosophila (Drosophila suzukii) arrived in North America in 2008 and has been been the No. 1 pest problem for soft-skinned fruits like berries for the last decade. Detecting the presence of these invasive flies could soon get easier, though, with a new molecular test for analyzing DNA in bulk trapping samples—sensitive enough to sniff out just one target D. suzukii in a sample of 2,000. And the best liquid for preserving trapped flies’ DNA comes from the dental-care shelf. (Photo by Justin Renkema, Ph.D.)