Trap Catches July 11, 2025.

The number of aphid species capture in the traps doubled over last week, with a much greater percentage being vector species.  With 19 traps reporting, traps recovered a total of 126 aphids, of which 53 were vectors.  This tracks well with the 13 year average; at this point in the growing year, some alternate hosts are maturing and becoming less suitable hosts, resulting in the development of winged aphids dispersing to establish new colonies on better food sources. If we stay true to the average pattern, we can expect vector numbers to start increasing sharply (see the graph below demonstrating the average regional capture from 2013-2024).  

The traps captured a number of different vector species, however, cotton-melon aphids were widespread, both buckthorn and potato aphids were present in several sites, and we started to see the appearance of Damson-Hop aphids at multiple sites this week. Green peach aphids remained low, with only a single individual being recovered at one location.  

Keep scouting and checking predictive sites!

The usual reminder:

- keep scouting; aphids can establish early after potatoes are up. Field scouting is less effective at finding aphid vector species that don't colonize potatoes. While these species will enter potato fields and probe plants, they can't survive on potatoes, consequently they'll keep moving through the field, sampling additional plants and spreading inoculum in the field. Remember to check predictive sites like this one and University of Wisconsin's weather based Vegetable Disease & Insect Forecasting site,(https://agweather.cals.wisc.edu/vdifn) which uses current weather data and historical populations as a predictor of current aphid vector populations. These will give you a better idea of the potential presence of non-colonizing aphids. 

- the research literature reports that the use of crop oils is the most consistent post-planting technique in preventing transmission of PVY and it can be improved with the addition of the insecticide Lambda-Cyhalothrin.

- most of the research indicates that insecticides on their own are usually not effective enough at suppressing PVY transmission, but are still very useful parts of your management program. Treating fields with one of the anti-feeding insecticides (e.g. Sivanto Prime, Sefina, Transform, Fulfill or Beleaf) to control colonizing aphids, such as green peach, potato, or cotton melon aphids, can be beneficial in decreasing movement of PVY inoculum within fields

- aphids preferentially first colonize fields at the edge. Using border crops in the headlands may decrease aphid colonization. But if using a border crop, it's a good idea to use treated seed to prevent the development of potential vector species in that border. And to include those border crops when treating the field for colonizing aphids.

 Happy scouting and have a great weekend!

Click on any image below for full-scale version.

The average regional PVY Vector capture and PVY Vector Risk Index by week for 2025. 

The regional average aphid vector captures/trap and PVY Vector Risk Index averaged from 2012 to 2023.  The dates are expressed in ISO Week numbers (a standardized method of presenting dates across years). 

Cumulative PVY Risk Index by Site to 7/11/2025

 Cumulative PVY Vector Risk Index by Site to 7/12/2024 for Comparison

Aphid Species Capture and PVY Vector Risk Index for the week ending 7/11/2025

Cumulative Aphid Species Capture and PVY Vector Risk Index to 7/11/2025

 

Trap Catches July 03, 2025.

The number of aphid species in the traps rose slightly over last week, but most were non-vector species.  With 9 traps reporting, traps recovered a total of 50 aphids, only 5 of which were vectors.  Having said that, we are slightly ahead of where we were on aphids counts this time last year. In 2024, the week after July 4 had a noticeable rise in vector flight, so we'll see what comes our way... In any case, aphids are flying and our rising temperatures will increase feeding rates and subsequent reproduction, we are rapidly getting into the aphid growth days of summer.  

Vector species this week consisted mostly of corn leaf aphid, but potato and English grain aphids were also recovered. Keep scouting and checking predictive sites!

Have a great Fourth of July weekend!

The usual reminder:

- keep scouting; aphids can establish early after potatoes are up. Field scouting is less effective at finding aphid vector species that don't colonize potatoes. While these species will enter potato fields and probe plants, they can't survive on potatoes, consequently they'll keep moving through the field, sampling additional plants and spreading inoculum in the field. Remember to check predictive sites like this one and University of Wisconsin's weather based Vegetable Disease & Insect Forecasting site,(https://agweather.cals.wisc.edu/vdifn) which uses current weather data and historical populations as a predictor of current aphid vector populations. These will give you a better idea of the potential presence of non-colonizing aphids. 

- the research literature reports that the use of crop oils is the most consistent post-planting technique in preventing transmission of PVY and it can be improved with the addition of the insecticide Lambda-Cyhalothrin.

- most of the research indicates that insecticides on their own are not effective enough at suppressing PVY transmission, but are still useful parts of your management program. Treating fields with one of the anti-feeding insecticides such as Sivanto Prime, Sefina or Transform to control colonizing aphids, such as green peach, potato, or cotton melon aphids, can be beneficial

- aphids preferentially first colonize fields at the edge. Using border crops in the headlands may decrease aphid colonization. But if using a border crop, it's a good idea to use treated seed to prevent the development of potential vector species in that border. And to include those border crops when treating the field for colonizing aphids.

 Happy scouting and have a safe and happy Fourth!

Click on any image below for full-scale version.

The average regional PVY Vector capture and PVY Vector Risk Index by week for 2025. 

The regional average aphid vector captures/trap and PVY Vector Risk Index averaged from 2012 to 2023.  The dates are expressed in ISO Week numbers (a standardized method of presenting dates across years). 

Cumulative PVY Risk Index by Site to 6/27/2025

 Cumulative PVY Vector Risk Index by Site to 7/05/2024 for Comparison

Aphid Species Capture and PVY Vector Risk Index for the week ending 7/03/2025

Cumulative Aphid Species Capture and PVY Vector Risk Index to 7/03/2025

 

Trap Catches June 27, 2025.

The number of aphid species in the traps rose this week. With 8 traps reporting, we had 27 vector aphids and 44 non-vectors captured. Aphids have started flying and so it's time to start scouting and applying management tools like crop oils. 

Vector species included a number of corn leaf aphids, soybean and buckthorn aphids are starting to be captured, and a number of potato aphids were recovered in at least one location. Non-vector species made up the majority of trap captures this week, but does indicate weather conditions are good for aphid movement.   

So, as a reminder:

- vector flights have started, so start scouting; aphids can establish early after potatoes are up. Field scouting is less effective at finding aphid vector species that don't colonize potatoes. While these species will enter potato fields and probe plants, they can't survive on potatoes, consequently they'll keep moving through the field, sampling additional plants and spreading inoculum in the field. Remember to check predictive sites like this one and University of Wisconsin's weather based Vegetable Disease & Insect Forecasting site,(https://agweather.cals.wisc.edu/vdifn) which uses current weather data and historical populations as a predictor of current aphid vector populations. These will give you a better idea of the potential presence of non-colonizing aphids. 

- the research literature reports that the use of crop oils is the most consistent post-planting technique in preventing transmission of PVY and it can be improved with the addition of the insecticide Lambda-Cyhalothrin.

- most of the research indicates that insecticides on their own are not effective enough at suppressing PVY transmission, but are still useful parts of your management program. Treating fields with one of the anti-feeding insecticides such as Sivanto Prime, Sefina or Transform to control colonizing aphids, such as green peach, potato, or cotton melon aphids, can be beneficial

- aphids preferentially first colonize fields at the edge. Using border crops in the headlands may decrease aphid colonization. But if using a border crop, it's a good idea to use treated seed to prevent the development of potential vector species in that border. And to include those border crops when treating the field for colonizing aphids.

 Happy scouting and have a great upcoming week.

Click on any image below for full-scale version.

The average regional PVY Vector capture and PVY Vector Risk Index by week for 2025. 

The regional average aphid vector captures/trap and PVY Vector Risk Index averaged from 2012 to 2023.  The dates are expressed in ISO Week numbers (a standardized method of presenting dates across years). 

Cumulative PVY Risk Index by Site to 6/27/2025

 Cumulative PVY Vector Risk Index by Site to 6/28/2024 for Comparison

Aphid Species Capture and PVY Vector Risk Index for the week ending 6/27/2025

Cumulative Aphid Species Capture and PVY Vector Risk Index to 6/27/2025

 Trap Catches June 20, 2025.

The number of vector aphid species remains low in the traps this week. With 8 traps reporting, we had 13 vector aphids captured. Several traps recovered Buckthorn aphid, with soybean aphids starting to appear in Central MN. No green peach aphids have been recovered so far. 

So, as a reminder:

- vector flights have started, so start scouting; aphids can establish early after potatoes are up. Field scouting is less effective at finding aphd vector species that don't colonize potatoes. While these species will enter potato fields and probe plants, cannot survive on potatoes, consequently, they'll keep moving through the field, sampling more plants and potentially moving inoculum already in the field to uninfected plants. Watch predictive sites (like this one) and check University of Wisconsin's weather based Vegetable Disease & Insect Forecasting site (https://agweather.cals.wisc.edu/vdifn) which uses current weather data and historical populations as a predictor of aphid vector populations.

- the research literature reports that the use of crop oils is the most consistent post-planting technique in preventing transmission of PVY and it can be improved with the addition of the insecticide Lambda-Cyhalothrin.

- most of the research indicates that insecticides on their own are not effective enough at suppressing PVY transmission, but are still useful parts of your management program. Treating fields with one of the anti-feeding insecticides such as Sivanto Prime, Sefina or Transform to control colonizing aphids, such as green peach, potato, or cotton melon aphids, can be beneficial

- if using a border crop, it's a good idea to use treated seed to prevent the development of potential vector species in that border.

 Lets hope the aphid populations stay low and we have a great season!

Click on any image below for full-scale version.

The average regional PVY Vector capture and PVY Vector Risk Index by week for 2025. 

The regional average aphid vector captures/trap and PVY Vector Risk Index averaged from 2012 to 2023.  The dates are expressed in ISO Week numbers (a standardized method of presenting dates across years). 

Cumulative PVY Risk Index to 6/20/2025

 Cumulative PVY Vector Risk Index to 6/28/2024 for Comparison

Aphid Species Capture and PVY Vector Risk Index for the week ending 6/06/2025

Cumulative Aphid Species Capture and PVY Vector Risk Index to 6/13/2025

Trap Catches June 01-06 & 06-13.

AND the aphid trapping season begins!

With 3 traps reporting over the first two weeks, numbers remain very low with aphid vectors being reported from only 1 site with 1 vector species each week. A slow start but we're happy to have more early season data!

We'll start mapping results next week!

The average regional PVY Vector capture and PVY Vector Risk Index by week for 2025. 

The regional average aphid vector captures/trap and PVY Vector Risk Index averaged from 2012 to 2023.  The dates are expressed in ISO Week numbers (a standardized method of presenting dates across years).    

Click on any image below for full-scale version.

Aphid Species Capture and PVY Vector Risk Index for the week ending 6/06/2025

Aphid Species Capture and PVY Vector Risk Index for the week ending 6/13/2025

Cumulative Aphid Species Capture and PVY Vector Risk Index to 6/13/2025

 

Trap Catches Identified to August 24th

Greetings!

The downward trend continues, with even fewer aphids this week than last!

This week we recovered a total of 133 aphids, 117 of which were vectors. We did, however, only have 10 sites reporting. Of those sites, we saw the heaviest flights from Sabin (36) and Staples (21).  Soybean Aphid was moving last week, with 25 being captured between Crookston, Staples, Sabin and Ballard.  If you have soybeans still in a susceptible growth stage (younger than R6), keep your eyes open.  There was some good news for the trapping area - no Green Peach this week! However, Dr. Gloom (Dr. Neil Gudmestad) mentioned to us yesterday that there have been reports of Green Peach aphid in southern Minnesota and South Dakota.  We don't have any traps down in southern MN so we sadly don't have data - may need to install a couple of traps down there next year...  

Just because the year is winding down a bit, that doesn't mean that aphids are completely done wreaking havoc. Aphids will be active well into September, so unless you've vine-killed - you should still be scouting!

Cumulative PVY Vector Risk Index Map to August 24th, 2018

Cumulative PVY Vector Risk Index Map for 2017 

(included for comparison)

Aphid Species Capture + PVY Risk - Week of August 19th, 2018

Total PVY Risk and Species Capture to August 24th, 2018