Testing continues to find zebra chip in suspicious samples taken from Idaho potato fields and sent to the University of Idaho.
In addition to a single plant collected from the university's Kimberly Research and Education Center, two others also have tested positive, according to a university pest alert.
The positive plants, as well as several others, had suspicious wilting symptoms.
On July 17, several plants with suspicious samples were collected from a grower's field from which liberibacter-positive potato psyllids had been trapped. It was in Twin Falls County.
These plants also tested positive for zebra chip, which is caused by the bacterium, CandidatusLiberibacter solanacearum.
Potato psyllids spread the bacteria, which is harmless to humans, when they feed on infected potato plants, then feed on healthy plants.
The positive plants mark the first time this season that zebra chip has been detected in the Pacific Northwest, according to the pest alert.
For more information on potato psyllids and zebra chip, visit the Kimberly center.