Project Updates
2018 Season
Aphid traps were checked for the last time of the season this week and pulled out of the field. Aphid counts have continued to decrease over the past few weeks with this week showing the lowest count at each trap site all season. All but one sites yielded single digit aphid counts. Virus results will continue to be updated to Aphid Tracker.
This week, all traps were sampled and aphids were captured at all sites. Aphid counts continue to drop as plants at most locations start to dry down. Plant tissue samples were taken this week and will be mailed to the Parma lab for virus testing.
This week, all traps were sampled and aphids were captured at all sites. Aphid counts appear to be dropping a little bit as plants are starting to dry down as well. Plant tissue samples will be taken next week.
This week, all traps were sampled and aphids were captured at all sites. We're still seeing a very large amount of aphids being captured in the pan traps. Still waiting on virus results.
This week, all traps were sampled and aphids were captured at all sites. This week yielded the largest amount of aphids trapped so far. Samples will be shipped to Parma for virus testing. We are still waiting of virus results from two weeks ago and last week.
Last week (6/11/18-6/15/18) the Entomological Society of America Pacific Branch meeting took place so traps were not sampled until Thursday: Aphids were found at all locations with the most aphids found at site #7. This week, aphids were found once again at all locations with the most aphids found at site #4. Aphids from both this week and last week were mailed to the Parma research lab yesterday to be tested for virus. Virus results from two weeks ago are in: 1 aphid tested positive for virus from site #4 (PEMV), 1 aphid from site #5 (PEMV), 1 aphid from site #7 (PEMV), and 2 aphids from site #8 (PEMV).
This week all aphid trap locations were sampled. Aphids were collected at all locations with the most aphids coming from sites 8 with twenty-three and site 9 with twenty-five aphids collected. Aphids will be tested for virus. We are currently still waiting on virus results from the aphids collected last week.
This week, all aphid trap locations, including the 5 new spring pea locations were sampled. Aphids were collected at all locations with the most aphids coming from sites 2 and 4 with thirty-six aphids collected from each location. Aphids will be tested for virus. This year is showing many more aphids at this point in the spring compared to last year.
Traps were checked this week. One aphid was found at site #1 and one aphid was found at site #3. These samples were sent to Parma for virus testing.
The 2018 field season is under way. We have four winter pea fields this year, and all traps have been put out and will remain out until the first hard freeze. Traps were placed at sites #1 and #2 this week. Traps were placed at site #4 last week and were checked for the first time this week; no aphids were collected. Traps were placed at site #3 two weeks ago and were checked last week and this week; no aphids were found.
2017 Season
This week, five pea aphids were collected at site 2 and three pea aphids were collected at site four. These aphids will be sent to Parma to test for virus.
The single pea aphid collected at site three last week tested positive for Pea Enation Mosaic Virus. This week, one aphid was collected at site three and once again, it tested positive for PEMV. Another aphid was collected this week at site four; it did not test positive for virus.
2016 Season
All but 4 sites had aphids present in pea aphid pan traps (76% of field sites had aphids present). The most abundant site was site #9 with a total of 4 alate pea aphids. ELISA plates are being read again for the 3rd time.
DAS-ELISA (double antibody sandwich enzyme-linked immunosorbent assay) tests of plant samples taken from each field have been analyzed.
Plant samples taken: 10 June 2016; 3 transects/site; 10 plants/transect; 16 total sites (1 site emerged as a wheat field [site was kept anyway] = site #4); 48 total samples; Plates read at 405 nm (wavelength) on 16 June 2016.
Overall - 50% of fields tested were positive for PEMV, BLRV or Both viruses.
Only 1 northern site (#3) tested positive for either virus, in this case BLRV and only 1 transect out of the 3 (33% virus incidence) was positive for that virus. All other sites that tested positive for BLRV/PEMV were located south of Moscow. Sites south and west of Moscow had the highest virus presence and incidence: sites #7, 8, 9, 10 and 12 tested positive for PEMV with a high incidence (14 out of 15 transects tested positive, 93% virus incidence). Sites south and east of Moscow: #16 and 17 tested positive for BLRV, PEMV or both (at a relatively low virus incidence, 33% and 66%, respectively). The cutoff date for treatment of alate viruliferous pea aphids (from UI data) shows that spraying before 32.49 DAE would be economical in preventing yield loss (quite early in the growing season). After looking at the fields today I believe all pea fields are past this cutoff date and thus virus damage to yield should be negligible this year. Secondary virus spread could be happening right now as I type this.
Aphids collected today (17 June 2016) have been sent south for PCR analyses.
If you'd like more information about our DAS-ELISA results please contact Brad Stokes (bstokes@uidaho.edu).
2015 Season
2014 Season
2013 Season
2012 Season
Maps of the approximate locations of fields testing positive for virus PEMV and BLVR can be viewed by clicking these links. The maps show the minimum percentage of infected plants in each location sampled. This is because the plants were pooled into sets for virus detection rather than sampled individually.
PM: Laboratory tests have been completed on plant tissue samples from all 34 sites in the survey. Nearly all sites were positive for virus in at least one plant (3%) of plants sampled. This is a higher incidence of virus at this point in the season than we have observed since starting our surveys in 2006. The prevalence of virus-positive plants varies among sites and we will be posting that information to the Aphidtracker by tomorrow.
AM: Unusually high infestations of aphids are being observed in the southern stretches of our study window, and specifically along the Rimrock road corridor. We are expecting data on the presence of virus imminently. We think producers across the region should proceed as though the disease risk is proportionately higher this year due to these infestation levels. ELISA results on the presence of virus particles in the plants from a survey of producer fields taken last week will be posted soon to this site.
The aphid sampling season will be starting soon. This week we will visit the Columbia Basin to survey alfalfa fields and other sources. In early May the traps will be deployed and we will begin entering the data into the 2012 map. We will let you know as soon as this is posted.
Meanwhile, we have finalized our three calculators and posted them to this site (go to home page and click on Decision Support System for Managing Aphids & Viruses where you will find links to each one). The first calculator helps you decide on treatments for your pea seed. The second one helps you make decisions about whether to spray your fields early for aphid. The third one calculates and Economic Injury Level for aphids pre-bloom. All of these have been developed based on our research data collected during the LVP. If questions arise in using these, please let us know!
2011 Season
We will be holding a workshop for those interested in participating in a "beta" test of the Epicollect system that will allow growers to submit their observations of pea aphids and virus using smartphones. The data will be posted to maps that can allow everyone to see where aphids are in real time.
Location: USA Dry Pea and Lentil Council Headquarters, 2780 W. Pullman Road
Time: 11:30am
What to bring: your smartphone (iPhone or Android only - does not work with Blackberry)
Provided: sandwiches!
RSVP: if you will be attending or have questions, please contact us by email: sanforde@uidaho.edu
2010 Season
Here is the full text from our Pulse Pipeline article for this date:
Virus symptoms report: This year, legume virus symptoms were first observed in the week of June 7 in pea fields near Almota, Albion and Uniontown, Washington. We also collected aphids carrying virus in traps in the same area relatively early in the season. Virus symptoms appeared later in fields near Genesee, Idaho, but have been essentially absent from fields in the northern part of the region. Last week, Lyndon Porter discovered virus symptoms in most of the 12 fields he sampled from Colfax to Moscow/Pullman. Two of the fields Lyndon scouted were severely injured. Jerry Mraz (PNW, Genesee) reports (June 20) that some symptoms are present in most of the fields he is scouting in his part of the region. In the north, Ken Fuchs (Co-Ag) reports (June 20) the crop looks mostly virus free except for rare, isolated plants. So the north-south differential observed in previous years seems to be holding. This week (June 19-20), we conducted a systematic visual survey for virus symptoms in pea fields at sites across the region where we have been trapping aphids this season. In each field, plants were sampled along two 100-meter transects. Along each transect, 50 plants were examined for symptoms every ten meters, for a total of 500 plants per transect. We sampled along two transects for a total of 1000 plants per field. We found the proportion of plants showing symptoms ranged from zero to 80% (Fig. 1) (all were pea fields except those indicated as lentil). As in prior years of our study, virus disease prevalence and percent infection is greater in the southern part than in the northern part of the region. Nonetheless, there are exceptions indicating local factors can override the drivers of this geographic trend. The symptoms we have seen this year (Figs. 2 and 3) are the distortion and windowing consistent with Pea enation mosaic virus, but our lab tests indicate Bean leaf roll virus is also present. Most fields only have symptoms in the upper nodes of affected plants so that the effects on yield this late in the season are uncertain. Where symptoms are more extensive, a yield impact is likely.
Aphid immigration patterns: It appears 2010 will be scored a “1” (low to moderate) on the “Clement” Index. This is because the cool and rainy June reduced aphid population growth and movement, although populations are now high in untreated fields. The source of virus inoculum this year remains uncertain since infectious aphids were rare in June. The warm spell in April could have brought in some undetected virus inoculum.
You can help: We would like to take advantage of the variability this year to measure the impacts of virus disease on pea yield. If you have symptoms like those shown in one of your fields and might be able to provide data on yield specific to that field, please let us know (sanforde@uidaho. edu). We would like to work with you.
We continue to see virus symptoms in certain fields in the southern part of the region, notably near Uniontown, Colfax and Genesee. We have reports, from Lyndon Porter who was scouting for fungal disease last week, that some virus symptoms (Pea enation mosaic) can be found in most fields from Colfax to Moscow/Pullman. Two of the fields scouted by Lyndon were severely injured. Jerry Mraz (PNW, Genesee) reports that some symptoms are present in most of the fields he is scouting. The degree of possible injury varies but is often confined to distortion of the uppermost pods and leaves. This late in the season it is difficult to know how much of an effect this could have on yield. Our surveys up north continue to find symptoms infrequently. Ken Fuchs (Co-Ag) also reports the crop looks virus free in the northern parts of the region except for rare, isolated plants. So the north-south differential observed in previous years is holding. We are completing a full symptom survey of all the trap sites north and south, today. We will have these results soon. A report will appear in the Pulse Pipeline this week.
Aphid numbers in traps are coming up across the region. Testing these aphids for presence of viruses is under way. Based on our surveys, virus symptoms in the crop remain confined to sites in the southern part of the region. For jpg photographs of representative symptoms observed near Site 17 click here (sympt1, sympt2, sympt3).
Plants and aphids from the southern part of the region have tested positive for Bean leaf roll virus. Suspected positives for PEMV are being retested. Aphids collected from sites 17 and 22 on June 3 are positive for BLRV.
The aphid traps for the season were installed on May 18 and collections began on May 24. View the trapping Locations and Data. In summary, we picked up one aphid in our reliable first detector site near Almota on May 24. May 27 we collected no aphids. This week we have picked up a few aphids from traps near Colton and Uniontown, despite the recent run of rainy weather.
We have also been sweeping pea fields at each of the sites. Some sites near Uniontown had aphids (winged and wingless) in the crop. This week we detected some in peas near Albion. Otherwise, the crop has been free of aphids throughout the region. Testing for virus in aphids from traps and sweep samples is underway and results will be communicated ASAP to this site.
Next week, we will be collecting plant tissue from pea fields adjacent to all of the trap sites and testing this tissue for viruses. We will use 3 100-meter transects into each field, collecting 30 plants and looking for symptoms. If you are hosting traps and do not want us in the field to take the samples for whatever reason, please let us know by following the "Feedback" link on the side bar.
The LVP personnel met for a 2-day retreat at the University of Idaho to set plans for the 2010 season. Trap locations will be determined soon. The Columbia Basin trip in April will go further west to seek PEMV sources, and will explore close to home along river canyons. Those interested in hosting traps should contact us, by emailing sanforde@uidaho.edu.
2009 Season
Traps in the basin. (Walla Walla, Touchet) for the week of April 20, these traps were free of pea aphids.
Traps in the Palouse region. We have begun to set traps in the Palouse for the 2009 season. Although only a few growers have been able to plant pea or lentil, we will begin collecting aphids on May 15, as in prior years. We will have approximately 35 sites and these will be located on the map soon. Thanks to Ken Fuchs (CoAg) and Mike Devoe (Genesee Union) for their help in locating the trap sites this year.
Columbia Basin. We made our annual foray into the Basin on April 17-19 this year. Despite the cool season, aphids were located in alfalfa in 13 of 27 sites surveyed. Abundance was low (about 0.1 aphids per sweep). Thanks to help from McGregor's field men, especially Marshall McKinleye we located traps in Walla Walla, Touchet and Dayton.
Traps. We are just beginning to determine positions for traps for this season. With the new funding, we will be placing more traps than in previous years. If you are interested in having a trap located near one of your fields, please contact us.
2008 Season
Pea aphids remain at very low levels in the traps. We have yet to detect virus in any trapped aphids. We have detected PEMV in just one aphid collected from alfalfa. Based on the similarities in aphid and virus incidence this year and last, it appears that 2008 will be very low risk of virus in pea and lentil on the Palouse. We plan to continue monitoring aphids in the traps and in the fields until the second week of July. Data will be updated as we do so.
Pea aphids are beginning to arrive in the trap network (see This Year 2008 Locations). The numbers per trap are about 1/2 of what they were at this date in 2007, due evidently to the continuing cool and wet weather in the region. So far we have not detected virus in any of the aphids collected. Sweep net samples at 25 sites (all those shown on the Locations map), have collected no or few aphids at many sites. Maximum numbers observed are 1 aphid per sweep.