Erik Wenninger, an associate professor of entomology and potato pathology at the University of Idaho's Kimberly Research & Extension Center, release the following statement this morning via PNWPestAlert.net:
This week, we had traps deployed in 59 of the 65 fields (91 percent) monitored this year (though we have not yet received traps from six of these fields); we found a total of 83 psyllids across 28 (53 percent) of the 53 fields with data.
Psyllids were collected on sticky traps in potato in the following counties: Canyon (12 fields), Owyhee (two fields), Gem (two fields), Elmore (three fields), Jerome (one field), Twin Falls (seven fields), Minidoka (two fields) and Oneida (one field).
From last week’s samples, two psyllids tested positive for Lso (liberibacter), the bacterium associated with zebra chip disease. These hot psyllids were collected from two different fields: one in Twin Falls and one in Jerome County. This is the first observation of Lso-positive psyllids in our monitoring program this year. This is about one week and two weeks later than the first observation of Lso-positive psyllids during 2019 and 2018, respectively.
Heat maps of this week’s results are included on the University of Idaho and Washington State University websites (see links below). Heat maps describe predicted psyllid densities across the landscape, based on our trap counts and on predictive models developed over six years of psyllid monitoring in Idaho. These maps, developed in collaboration with WSU, should be used as a guideline, but not a definitive count of the number of insects in any given field at any given point in time. “Low,” “Moderate,” “High” and “Very High” designations are arbitrary categories that illustrate relative abundance and should not be used as thresholds. More details on the heat maps can be found in Potato Progress Volume XVII, Number 2, Feb.15, 2017.
Psyllid captures were a bit higher this week, though similar to total captures during late July to early August last year. Given this increase and the first observation this year of Lso-positive psyllids in Idaho, we urge growers to have their IPM programs in place.
More information can be found here.
- Click on the links under “Updated weekly reports” for details on trap captures.
- Click on the “Psyllid Management” link on the left panel for information on psyllid and zebra chip biology and management.