US: Disease-carrying potato psyllids increase in the Northwest

The potato psyllid insect pest is being seen in rapidly growing numbers across the Pacific Northwest, but few so far have been found to carry a potentially devastating disease. Last week, Washington State University Extension researchers found the bugs on 79 percent of field samples throughout the Lower Columbia Basin, up from 60 percent the week before and 50 percent the week before that. Each sample contained an average of 3.1 psyllids, up from 0.6 the week before. The psyllids, which feed on potato leaves, “are a big deal because they can transmit a bacterium to potatoes that causes zebra chip disease,” said Carrie Wohleb, a WSU professor and regional vegetable specialist in Moses Lake. More