Final psyllid monitoring update of 2026 season

This is the final report of the 2026 potato psyllid / Lso monitoring season.

Last week we provided a season wrap up, but we did not yet have the final results of Lso testing of the most recently captured potato psyllids. Thankfully, only 3 more psyllids tested positive: 2 from a site in Elmore County and 1 from a site in Twin Falls County. The overall percent incidence of Lso in psyllids collected this season landed at just under 3%.

The following is a summary of last week’s wrap up: The risk of ZC may have been moderately elevated by the relatively high number of psyllids captured, but mitigated a bit by the relatively low prevalence of Lso in psyllids. The percentage of psyllids with Lso was lower this year then for each of the previous four years.

It is worth noting that several sites in Canyon County, and a few in Elmore and Twin Falls counties, accounted for much of the abundance of psyllids as well as the “hot” psyllids that we captured. So risk of ZC has not been uniform across the state. As is typical, we saw few psyllids in the Upper Snake region, and none of them tested positive for Lso.

For any growers that have not vine killed yet, we urge you to keep your IPM programs going, especially for areas that are at slightly higher risk.

A huge thank you to all our cooperators who helped to deploy and retrieve so very many yellow sticky traps! And thanks to the growers who let us use their fields for this work! We could not do this work without your help.