Psyllid numbers stop climbing; eleven more Lso-positive psyllids

• This week we received traps from 40 of the 55 fields that we are monitoring; many fields have now undergone vine kill.
• We captured a total of 199 psyllids spread across 20 fields.
• Captures were from the following counties: Canyon, Owyhee, Elmore, Jerome, Twin Falls, Cassia, and Minidoka.
• Of the 281 psyllids captured last week, 11 tested positive for Lso. Six were from Canyon County, three were from Elmore County, and two from Twin Falls County.
• For psyllids captured this week, we expect to have results on Lso incidence next week.

Overall psyllid captures continue to be relatively high, but thankfully the total captures (and captures per trap) declined relative to last week. Lso incidence has been relatively low for the most part, though we have recently seen several “hot” psyllids from the Treasure and Magic valleys. Canyon, Elmore, and Twin Falls counties have tended to have the most psyllids and the most Lso-positive psyllids in recent weeks. The high captures last week were likely related to psyllids dispersing from senescing fields, and the more moderate captures this week were likely related to cooler temperatures. We urge growers to keep their IPM programs going, especially for areas that might be at slightly higher risk. In our research with Russet Burbank, tubers still have some risk of showing ZC symptoms in storage if infection occurs within 1-2 weeks before vine kill.

More information on management of potato psyllids and ZC can be found here:
https://www.uidaho.edu/extension/food/ipm/ag-pests/psyllids

To view the weekly data by site in the old spreadsheet format: https://tinyurl.com/potatopsyllid