Adult psyllids collected from a sticky card on a commercial field in Twin Falls County, ID, on June 19 have tentatively tested positive for Liberibacter, the bacterium that causes zebra chip. It’s the first such find in 2012.
According to the University of Idaho’s Erik Wenninger, an assistant professor of IPM entomology, PCR tests conducted last week by University of Idaho virologist Alex Karasev’s lab are being followed up this week by sequencing the bands to confirm that the sequences belong to Liberibacter.
In a Monday post on the Pacific Northwest & Treasure Valley Pest Alert Network, Wenninger stated that additional psyllids collected last week from this site and from the U-Idaho Kimberly R&E Center will be tested this week for Liberibacter.
Here is the remainder of Wenninger’s post: “We still have not found psyllids of any life stage on potato plants themselves. However, field bindweed was found along the edge of the field near the sticky card with “hot” psyllids, and today we found potato psyllid eggs (but no other life stages) on several field bindweed plants.
“The importance of this finding in relation to psyllid infestations in potato remains to be explored, but, considering potato psyllids have a broad host range that includes at least 20 plant families, weed management might aid in psyllid management in potato fields. The infested field bindweed also will be tested for Liberibacter.
“This is the first (preliminary) finding of Liberibacter-infected psyllids in the Pacific Northwest this season; however, we still strongly recommend that fields be scouted in order to make the most sound and appropriate management steps for a given field.”