Trap Catches identified to 9-14

Greetings!

Last week we only received five trap samples.  Many locations have been harvested by this point.  There are still a few aphids out there.

Cumulative PVY Vector Risk INdex maps - click on the map for a full scale image.

 

Trap Catches Identified to September 4

Greetings!

Vector numbers and PVY risk have dropped dramatically from the past two weeks.  Still seeing some bird cherry oat and soybean aphids but in much smaller numbers.  Ada led the sites with a PVY Risk of 3.15, down from 12.81 lasat week.  All other sites reporting index values below 2.0, many below 1.0.  

We've had fewer sites reporting as some are beginning to vine kill and harvest.  We will continue to report as long as we get traps in!  Good luck out there!

Scouting for aphids in potatoes:
- Select leaves from the lower to mid canopy.  Lower, older leaves will have more established colonies and aphids prefer the balance of nutrients found here; aphids are rarely found on leaves in the upper canopy.
 - Avoid leaves on the ground or in contact with the soil.
 - In seed potatoes there is only a threshold for PLRV (10 aphids/100 leaves), reactive application of insecticides an effective control for PVY.
 - The use of feeding suppressing insecticides, such as pymetrozine (Fulfill®) or flonicamid (Beleaf®) and refined crop oils, such as Aphoil and JMS Stylet Oil, at or prior to field colonization by aphids may reduce the transmission of PVY within fields. Some other insecticides, such as clothianidin (Belay®), imidacloprid (Admire Pro® or Provado®), and spirotetramat (Movento®), have also been demonstrated to reduce the transmission of PVY.
- In table stock potatoes, a treatment threshold of 30 aphids /100 leaves should deter yield loss due to aphid feeding.

PVY-Vector Risk Index - click on map for full size

 

Trap Catches Identified to 8-31

Greetings!

It looks like the cooler weather has begun to decrease aphid numbers.  We are reporting two weeks worth of data for the Hatton and Tappen sites, and in each case there is a significant reduction in total vectors and PVY risk.  Green peach numbers are down and soybean aphids have dropped dramatically in all locations except Ada.  

Scouting for aphids in potatoes:
- Select leaves from the lower to mid canopy.  Lower, older leaves will have more established colonies and aphids prefer the balance of nutrients found here; aphids are rarely found on leaves in the upper canopy.
 - Avoid leaves on the ground or in contact with the soil.
 - In seed potatoes there is only a threshold for PLRV (10 aphids/100 leaves), reactive application of insecticides an effective control for PVY.
 - The use of feeding suppressing insecticides, such as pymetrozine (Fulfill®) or flonicamid (Beleaf®) and refined crop oils, such as Aphoil and JMS Stylet Oil, at or prior to field colonizach ap Cattion by aphids may reduce the transmission of PVY within fields. Some other insecticides, such as clothianidin (Belay®), imidacloprid (Admire Pro® or Provado®), and spirotetramat (Movento®), have also been demonstrated to reduce the transmission of PVY.
- In table stock potatoes, a treatment threshold of 30 aphids /100 leaves should deter yield loss due to aphid feeding.

Cumulative PVY-VRI Risk Map for Trap Catch up to Aug 24 and Total for 2014 (click on map for full size )

Trap Catches Identified to 8-24

Greetings!

Aphid numbers are up in some areas, down in others.  We are still seeing high numbers of soybean aphid and higher numbers of green peach aphid that are contributing to high PVY Risk.  Hopefully the recent cool weather will lower numbers for the coming week!

The PVY Vector Risk Index numbers on the table represent the amount of pressure in comparison to green peach aphids that is occurring at any given site.  The cumulative seasonal PVY-VRI for trap contents identified up until Aug 24 for all sites is presented on the first map, the second is the total regional PVY-VRI from 2014.

Scouting for aphids in potatoes:
- Select leaves from the lower to mid canopy.  Lower, older leaves will have more established colonies and aphids prefer the balance of nutrients found here; aphids are rarely found on leaves in the upper canopy.
 - Avoid leaves on the ground or in contact with the soil.
 - In seed potatoes there is only a threshold for PLRV (10 aphids/100 leaves), reactive application of insecticides an effective control for PVY.
 - The use of feeding suppressing insecticides, such as pymetrozine (Fulfill®) or flonicamid (Beleaf®) and refined crop oils, such as Aphoil and JMS Stylet Oil, at or prior to field colonization by aphids may reduce the transmission of PVY within fields. Some other insecticides, such as clothianidin (Belay®), imidacloprid (Admire Pro® or Provado®), and spirotetramat (Movento®), have also been demonstrated to reduce the transmission of PVY.
- In table stock potatoes, a treatment threshold of 30 aphids /100 leaves should deter yield loss due to aphid feeding.

For full sized maps, click on images... 

 

Trap Catches Identified to August 17

Greetings!

Another week with high aphid pressure.  We are seeing more green peach aphid across many sites including a whopping 18 from the Sabin trap!  Soybean aphid numbers are still high.  Several locations have risk indices in the double digits: Ada, Perham, Sabin, and Tappen.

As always, keep scouting!

The PVY Vector Risk Index numbers on the table represent the amount of pressure in comparison to green peach aphids that is occurring at any given site.  The cumulative seasonal PVY-VRI up until Aug 17 for all sites is presented on the first map, the second is the total regional PVY-VRI from 2014.

Scouting for aphids in potatoes:
- Select leaves from the lower to mid canopy.  Lower, older leaves will have more established colonies and aphids prefer the balance of nutrients found here; aphids are rarely found on leaves in the upper canopy.
 - Avoid leaves on the ground or in contact with the soil.
 - In seed potatoes there is only a threshold for PLRV (10 aphids/100 leaves), reactive application of insecticides an effective control for PVY.
 - The use of feeding suppressing insecticides, such as pymetrozine (Fulfill®) or flonicamid (Beleaf®) and refined crop oils, such as Aphoil and JMS Stylet Oil, at or prior to field colonization by aphids may reduce the transmission of PVY within fields. Some other insecticides, such as clothianidin (Belay®), imidacloprid (Admire Pro® or Provado®), and spirotetramat (Movento®), have also been demonstrated to reduce the transmission of PVY.
- In table stock potatoes, a treatment threshold of 30 aphids /100 leaves should deter yield loss due to aphid feeding.

For full sized maps, click on images...

Trap Catches Identified to 8-7

Greetings!

Aphid numbers remain high!  This is mostly due to large numbers of soybean aphid but we are seeing large numbers of english grain, blackbean, and buckthorn aphids in certain locations as well.  

We are seeing more green peach aphids in the traps, contributing to larger PVY Risk Indices.  Motley is on top this week with an index value of 23.49 followed by Ada at 13.91.  

Crookston, Erskine, Langdon, and Lake of the Woods are in good shape with risk indices at less than one.

As always, keep scouting!

Scouting for aphids in potatoes:
- Select leaves from the lower to mid canopy.  Lower, older leaves will have more established colonies and aphids prefer the balance of nutrients found here; aphids are rarely found on leaves in the upper canopy.
 - Avoid leaves on the ground or in contact with the soil.
 - In seed potatoes there is only a threshold for PLRV (10 aphids/100 leaves), reactive application of insecticides an effective control for PVY.
 - The use of feeding suppressing insecticides, such as pymetrozine (Fulfill®) or flonicamid (Beleaf®) and refined crop oils, such as Aphoil and JMS Stylet Oil, at or prior to field colonization by aphids may reduce the transmission of PVY within fields. Some other insecticides, such as clothianidin (Belay®), imidacloprid (Admire Pro® or Provado®), and spirotetramat (Movento®), have also been demonstrated to reduce the transmission of PVY.
- In table stock potatoes, a treatment threshold of 30 aphids /100 leaves should deter yield loss due to aphid feeding.

**NEW** PVY Vector Risk Index
As you’ve heard us mention, not all species of aphid equally transmit PVY and some are better at transmission than others (green peach being the most efficient vector of PVY).  So, the total number of aphids in a trap don't necessarily refelct just how much vector pressure there is at that location. We've created an index, the PVY Vector Risk Index, to compare aphid numbers and their relative efficiency as a vector compared to the Queen of PVY vectors (green peach aphid!).  Using averaged reference comparisons from the literature, we multiplies the number of each aphid species captured by the associated comparison to more accurately depict risk posed by the species being trapped.  We then sum the totals.  The PVY-VRI values are presented on the tables below but also on maps comparing current cumulative risk to the total risk from the sample sites of last year (to compare with your local winter grow out results).  Click on the map for full sized image.

Trap Catches Identified to 7-31

Greetings!

Vector numbers continue to climb.  We continue to see a major influx of soybean aphid with catches of over 100 at the Lake of the Woods and Motley locations.  

Forest River and Hatton had last weeks traps come in on Monday and are included in this report as well.

Keep Scouting!

Scouting for aphids in potatoes:
- Select leaves from the lower to mid canopy.  Lower, older leaves will have more established colonies and aphids prefer the balance of nutrients found here; aphids are rarely found on leaves in the upper canopy.
 - Avoid leaves on the ground or in contact with the soil.
 - In seed potatoes there is only a threshold for PLRV (10 aphids/100 leaves), reactive application of insecticides an effective control for PVY.
 - The use of feeding suppressing insecticides, such as pymetrozine (Fulfill®) or flonicamid (Beleaf®) and refined crop oils, such as Aphoil and JMS Stylet Oil, at or prior to field colonization by aphids may reduce the transmission of PVY within fields. Some other insecticides, such as clothianidin (Belay®), imidacloprid (Admire Pro® or Provado®), and spirotetramat (Movento®), have also been demonstrated to reduce the transmission of PVY.
- In table stock potatoes, a treatment threshold of 30 aphids /100 leaves should deter yield loss due to aphid feeding.

Trap Catches Identified to 7-24

Greetings!

This week we are starting to see some major aphid captures.  Soybean aphid numbers of ballooned with six sites collected them in the double digits.  Starting to see more English grain aphid in some areas as well.  More importantly, we caputred 12 green peach aphids this week from four locations including seven from Ada.  Ada had a whopping 107 vectors with a PVY Risk Index of 21.4.  Other locations with high PVY Risk Indices include Perham (7.91), Sabin (6.27), Motley (5.82), and Crookston (5.41).  The Langdon, Sabin, and Tappen traps all had PVY Risk Indices below 1.0.

Keep Scouting!

Scouting for aphids in potatoes:
- Select leaves from the lower to mid canopy.  Lower, older leaves will have more established colonies and aphids prefer the balance of nutrients found here; aphids are rarely found on leaves in the upper canopy.
 - Avoid leaves on the ground or in contact with the soil.
 - In seed potatoes there is only a threshold for PLRV (10 aphids/100 leaves), reactive application of insecticides an effective control for PVY.
 - The use of feeding suppressing insecticides, such as pymetrozine (Fulfill®) or flonicamid (Beleaf®) and refined crop oils, such as Aphoil and JMS Stylet Oil, at or prior to field colonization by aphids may reduce the transmission of PVY within fields. Some other insecticides, such as clothianidin (Belay®), imidacloprid (Admire Pro® or Provado®), and spirotetramat (Movento®), have also been demonstrated to reduce the transmission of PVY.
- In table stock potatoes, a treatment threshold of 30 aphids /100 leaves should deter yield loss due to aphid feeding.

Trap Catches Identified to 7-17

As you’ve heard us mention, not all species of aphid equally transmit PVY.  While Green Peach aphid, Myzus persicae, is the most efficient vector of the virus, some aphid species don’t transmit the virus at all and many fall somewhere in the middle.  The table below contains the relative efficiency factors (REF), or how well each aphid species transmits PVY compared to green peach aphid.  The REF values we are using are averaged from the literature.  Because not all aphid species transmit the virus equally, the total number of aphid vectors at a given site does not give us the whole picture into the risk of virus transmission.  We have created a value, called the Relative PVY Risk Index, which multiplies the number of each aphid species captured by the associated REF to more accurately depict relative risk of PVY transmission.  Keep in mind, this is a snapshot in time, the Relative PVY Risk Index for any week just represents which site got the most aphids that are most effective at vectoring PVY.  The Index doesn't indicate which site will have the greatest risk over the season but should provide insight for making management decisions.

 

This week, our Forest River trap had the highest Relative PVY Risk Index and thus the greatest risk of PVY transmission.  This site collected one green peach aphid and 34 total vector species.  Despite having fewer vectors than some of the other sites, Staples had the second highest Relative PVY Risk Index because it captured 4 buckthorn aphids, the second most efficient PVY vector.   Crookston, Sabin, Stephen, Motley, Tappen, and Hatton all had PVY Risk Indices over one.  A couple of traps were down this week but should be back up and running for next weeks catch.

Keep scouting!

Scouting for aphids in potatoes:
- Select leaves from the lower to mid canopy.  Lower, older leaves will have more established colonies and aphids prefer the balance of nutrients found here; aphids are rarely found on leaves in the upper canopy.
 - Avoid leaves on the ground or in contact with the soil.
 - In seed potatoes there is only a threshold for PLRV (10 aphids/100 leaves), reactive application of insecticides an effective control for PVY.
 - The use of feeding suppressing insecticides, such as pymetrozine (Fulfill®) or flonicamid (Beleaf®) and refined crop oils, such as Aphoil and JMS Stylet Oil, at or prior to field colonization by aphids may reduce the transmission of PVY within fields. Some other insecticides, such as clothianidin (Belay®), imidacloprid (Admire Pro® or Provado®), and spirotetramat (Movento®), have also been demonstrated to reduce the transmission of PVY.
- In table stock potatoes, a treatment threshold of 30 aphids /100 leaves should deter yield loss due to aphid feeding.

 

Trap Catches identified to 7-10

Greetings!

Aphid numbers remain relatively low.  Note that we received two samples from some of our cooperators this week (Forest River, Hatton, Motley, and Staples) due to the holiday last week. Motley, Perham and Ada seeing some higher numbers than the rest of the sites.  Two green peach aphids were collected this week, one from Forest River and one from Perham.  Remember, the green peach aphid is by far the most efficient vector of PVY.  

Keep scouting!

Scouting for aphids in potatoes:
- Select leaves from the lower to mid canopy.  Lower, older leaves will have more established colonies and aphids prefer the balance of nutrients found here; aphids are rarely found on leaves in the upper canopy.
 - Avoid leaves on the ground or in contact with the soil.
 - In seed potatoes there is only a threshold for PLRV (10 aphids/100 leaves), reactive application of insecticides an effective control for PVY.
 - The use of feeding suppressing insecticides, such as pymetrozine (Fulfill®) or flonicamid (Beleaf®) and refined crop oils, such as Aphoil and JMS Stylet Oil, at or prior to field colonization by aphids may reduce the transmission of PVY within fields. Some other insecticides, such as clothianidin (Belay®), imidacloprid (Admire Pro® or Provado®), and spirotetramat (Movento®), have also been demonstrated to reduce the transmission of PVY.
- In table stock potatoes, a treatment threshold of 30 aphids /100 leaves should deter yield loss due to aphid feeding.

Trap Catches Identified to 7-2

Although we are seeing greater numbers of aphids, vector species remain low.  Continue to scout and have a wonderful fourth of July!

Scouting for aphids in potatoes:
- Select leaves from the lower to mid canopy.  Lower, older leaves will have more established colonies and aphids prefer the balance of nutrients found here; aphids are rarely found on leaves in the upper canopy.
 - Avoid leaves on the ground or in contact with the soil.
 - In seed potatoes there is only a threshold for PLRV (10 aphids/100 leaves), reactive application of insecticides an effective control for PVY.
 - The use of feeding suppressing insecticides, such as pymetrozine (Fulfill®) or flonicamid (Beleaf®) and refined crop oils, such as Aphoil and JMS Stylet Oil, at or prior to field colonization by aphids may reduce the transmission of PVY within fields. Some other insecticides, such as clothianidin (Belay®), imidacloprid (Admire Pro® or Provado®), and spirotetramat (Movento®), have also been demonstrated to reduce the transmission of PVY.
- In table stock potatoes, a treatment threshold of 30 aphids /100 leaves should deter yield loss due to aphid feeding.

Trap catches identified to 6/26

Greetings!

Getting some more traps up and running.  Aphid numbers remain low although we expect them to increase as the season moves along.

Should be getting the rest of the locations coming in soon.  If you have a trap and need assistance let us know!  Big thanks to our cooperators thus far!

Scouting for aphids in potatoes:
- Select leaves from the lower to mid canopy.  Lower, older leaves will have more established colonies and aphids prefer the balance of nutrients found here; aphids are rarely found on leaves in the upper canopy.
 - Avoid leaves on the ground or in contact with the soil.
 - In seed potatoes there is only a threshold for PLRV (10 aphids/100 leaves), reactive application of insecticides an effective control for PVY.
 - The use of feeding suppressing insecticides, such as pymetrozine (Fulfill®) or flonicamid (Beleaf®) and refined crop oils, such as Aphoil and JMS Stylet Oil, at or prior to field colonization by aphids may reduce the transmission of PVY within fields. Some other insecticides, such as clothianidin (Belay®), imidacloprid (Admire Pro® or Provado®), and spirotetramat (Movento®), have also been demonstrated to reduce the transmission of PVY.
- In table stock potatoes, a treatment threshold of 30 aphids /100 leaves should deter yield loss due to aphid feeding.

Trap Catches identified to June 06/15

And so it begins.....
Traps have begun to report and there have been some aphids flying already.  Including one Green Peach Aphid recovered from Ada, MN!

Not an auspicious start to the year but I suspect the winged GPA recovered in the trap is a recent immigrant to our fair Valley.  The winds were right for immigration events two weeks ago and we had rain, which would have brought airborne aphids to the ground.

While it's doubtful we have treatable populations of aphids in potatoes yet, this week's trap catch indicates it's never too early to start scouting...

Scouting for aphids in potatoes:
- Select leaves from the lower to mid canopy.  Lower, older leaves will have more established colonies and aphids prefer the balance of nutrients found here; aphids are rarely found on leaves in the upper canopy.
 - Avoid leaves on the ground or in contact with the soil.
 - In seed potatoes there is only a threshold for PLRV (10 aphids/100 leaves), reactive application of insecticides an effective control for PVY.
 - The use of feeding suppressing insecticides, such as pymetrozine (Fulfill®) or flonicamid (Beleaf®) and refined crop oils, such as Aphoil and JMS Stylet Oil, at or prior to field colonization by aphids may reduce the transmission of PVY within fields. Some other insecticides, such as clothianidin (Belay®), imidacloprid (Admire Pro® or Provado®), and spirotetramat (Movento®), have also been demonstrated to reduce the transmission of PVY.
- In table stock potatoes, a treatment threshold of 30 aphids /100 leaves should deter yield loss due to aphid feeding.