This season is shaping to be another costly year for Northwest potato production, given the early confirmations of potato psyllids infected with the Liberibacter bacterium, which causes zebra chip disease, in Western Idaho and late blight in Walla Walla, Wash. University of Idaho Extension entomologist Erik Wenninger announced June 2 that the first two psyllids captured by the state’s extensive psyllid monitoring program both tested positive for Liberibacter. Zebra chip, which creates bands in tuber flesh that darken during frying, first surfaced in the Northwest in 2011. The infected Idaho psyllids were trapped in separate fields in Canyon County and discovered during an analysis of sticky traps in late May. Not since 2012 have the first psyllid samples collected by the monitoring program tested positive, Wenninger said. Wenninger said a single psyllid was detected June 3 on a sticky trap collected from Magic Valley earlier that week. The Magic Valley psyllid is still being tested. More