Huanglongbing—also known as HLB or citrus greening bacteria. Bill Schneider, chief research scientist tells us how that can take place. The Florida-based detector dogs were trained in a program funded by a USDA grant and run by Tim Gottwald at the USDA research station in Fort Pierce, Florida. Grafton-Cardwell noted the dogs were trained to distinguish HLB from other diseases, such as Phytophthora—and that detection of HLB bacteria is not necessarily a death sentence.
"When a psyllid lays down some bacteria, it doesn't always turn into an infection," she said. "Sometimes the bacteria just sit there, so the dogs are able to detect the bacteria, but the tree may or may not be becoming diseased. And it takes, sometimes, several years for the bacteria to spread throughout the tree."
Grafton-Cardwell said although some people want to see more proof of the dogs' abilities to find HLB, others say they need to be used because citrus farmers along travel corridors know they're at risk.