Idaho: Potato Psyllid Monitoring Program Updates

Update: August 9, 2024

This week's psyllid testing update has been released:

21 psyllids were caught across Payette, Canyon, Owyhee, and Twin Falls Counties.

4 of last week's psyllid captures tested positive for Lso (Payette - 1, Elmore - 1, Twin Falls - 2)

The monitoring team says that captures are "similar to the last two years" and that "overall captures have been relatively low this year, which should mitigate risk of ZC even with slightly higher Lso incidence in psyllids."

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What is zebra chip disease and what do potato psyllids have to do with it?

Zebra chip is a disease that affects the potato plant, so named because it gives a "zebra stripe" effect on the flesh of potatoes, especially when fried. While it does not make the potato inedible, it can result in loss of flavor and cause cosmetic issues that make the potato less marketable.

It was first identified in the early 1990s and is believed to be spread solely through the potato psyllid, which acts as a disease vector, carrying the liberibacter (Lso). Research for the disease is still ongoing, but it is believed pest management of the potato psyllid is the best option for preventing crop damage and loss.

August 2, 2024

This week's testing update is as follows.

• 38 Psyllids were captured in Payette, Canyon, Owyhee, Elmore, Twin Falls, and Minidoka counties.
• Three psyllids from last week's capture tested positive for Lso (one in Payette, two in Twin Falls)
• Captures remain moderate and similar to last year.

The psyllid monitoring team comments, "Thankfully overall captures have been moderate this year, which should mitigate risk of ZC even with slightly higher Lso incidence in psyllids."

July 26, 2024

This week's psyllid monitoring report notes:

• 30 psyllids were trapped across 14 fields.
• Captures were in Payette, Canyon, Gooding, Twin Falls, Minidoka, and Bingham Counties.
• Last week's psyllids did not test positive for Lso.

The team notes that based on the current testing and trapping numbers, there is a "good sign that overall Lso incidence for this season may be low."

July 19, 2024

The latest psyllid monitoring information has been released, with the following to report:

• Psyllid captures are going down to expected levels
• Three Lso-positive psyllids have been found in Twin Falls County (two at Kimberly Research & Extension Center).
• Captures in the past two weeks were from  Canyon, Owyhee, Jerome, Twin Falls,  Gooding, Bannock, Cassia, and Bingham.

Original Report - July 8, 2024

The latest monitoring season for potato psyllid in Idaho has begun, with several captures in the first week of trapping.

The University of Idaho notified the Pacific Northwest Pest Alert Network that testing had begun across 58 fields in the state, and will last for at least ten weeks. The program focuses on commercial potato fields in southern Idaho and monitors for potato psyllids, zebra chip disease (ZC), and liberibacter (Lso).

In the first week of trapping, the monitoring team captured 53 psyllids across 19 fields as follows:

• Payette - 1 psyllid captured
• Owyhee - 1 psyllid captured
• Jerome - 1 psyllid captured
• Cassia - 1 psyllid captured
• Minidoka - 1 psyllid captured
• Bingham - 1 psyllid captured
• Canyon (3 fields) - 3 psyllid captured
• Twin Falls (10 fields) - 43 psyllids captured

Testing for Lso incidence is underway for these captures. U of I notes:

Psyllid captures this week were higher than at this time in the last two years. It is noteworthy that most of the captures came from the Magic Valley, and most of those from one field (though captures in Twin Falls County were widespread). We typically see higher captures in the Treasure Valley before the Magic Valley, so these observations are unusual.