Season wrap up, part 1

Last week we reported on our last trapping week of the season. We had hoped to have Lso test results by today for psyllids captured last week; unfortunately delays in shipping inhibited our ability to do so, but we expect to have those results next week. However, we can still summarize what we’ve reported on this season.

Overall captures were relatively high this season, with captures similar to the most recent “high water mark” of 2020 and 2021. Captures during the last two weeks were notably even higher than for the same time period during those two previous years. So far the overall percent incidence of Lso in psyllids is around 3%.

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 during 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, account for much of the abundance of psyllids as well as the “hot” psyllids that we’ve been capturing. So risk of ZC is not uniform across the state. As is typical, we saw few psyllids in the Upper Snake region, and none of them tested positive for Lso so far.

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

Next week, we’ll report on the last batch of psyllids undergoing Lso testing.