The potato psyllid (Bactericera cockerelli), also known as the tomato psyllid, is a pest that can spread plant diseases to various crops. Potato psyllids and other psyllid species are difficult to track, and thus their non-crop whereabouts have been poorly understood. A new study, however, shows that DNA analysis of psyllids’ gut content can identify plants they previously fed on, providing clues about the stops they make before infesting crop fields. (Photo credit: Whitney Cranshaw, Colorado State University, Bugwood.org)