Trap Catches Identified to September 14th

Greetings!

Trap catches are decreasing rapidly with only 25 aphids captured this week, 13 of which were vector species, recovered from 5 locations reporting.  This will likely be the last week of traps reporting.

One Green Peach Aphid was recovered from Humboldt, the rest of the sites reporting few if any vector species.

We'll put up a season summary next week.

Good luck to those of you who are beginning to harvest!

The PVY Risk Index Index  Not all species of aphid are equally efficient at transmitting PVY, some are better than others (green peach being the most efficient vector of PVY).  So, the total number of aphids in a trap don't necessarily reflect just how much vector pressure there is at that location. The PVY Vector Risk Index compares aphid numbers, incorporating their relative vector efficiency compared to the Queen of PVY vectors (green peach aphid!).  Using averaged reference comparisons from the literature, we multiply the number of each aphid species captured by its efficiency compared to Green Peach Aphid 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).

 Cumulative PVY Vector Risk Index Map to September 14th, 2018

Cumulative PVY Vector Risk Index Map for 2017 

(included for comparison)

Aphid Species Capture + PVY Risk - Week of September 8-14th, 2018

Total PVY Risk and Species Capture to September 14th, 2018

Trap Catches Identified to August 31th

Greetings!

With the season winding down, aphid numbers are definitely trending downwards, only 52 aphids, 38 of which were vector species were recovered from traps at 10 locations this week.  

Only three Green Peach Aphids were recovered this week (all from Grenora) and Soybean Aphids were completely absent from this week's trap samples.  Grain aphids are also dwindling and the two most numerous vector aphid species in traps this week were Foxglove and Buckthorn aphids.  

Many locations have already vine killed, but if not, keep in mind, if there are green vines, aphids will still probe and transfer any inoculum they pick up.  Most of our PVY in MN and ND is transmitted to the plant in the latter part of the season.

We'll probably only run the network another 1-2 weeks, hope you're having a great late season!  

Scouting for aphids in potatoes:

• Select leaves from the lower to mid canopy.  Start at the edge of the field.
• 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.

The PVY Risk Index Index  Not all species of aphid are equally efficient at transmitting PVY, some are better than others (green peach being the most efficient vector of PVY).  So, the total number of aphids in a trap don't necessarily reflect just how much vector pressure there is at that location. The PVY Vector Risk Index compares aphid numbers, incorporating their relative vector efficiency compared to the Queen of PVY vectors (green peach aphid!).  Using averaged reference comparisons from the literature, we multiply the number of each aphid species captured by its efficiency compared to Green Peach Aphid 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).

Cumulative PVY Vector Risk Index Map to August 31, 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

Aphid Alert 8-24-2018

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!

Scouting for aphids in potatoes:

• Select leaves from the lower to mid canopy.  Start at the edge of the field.
• 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.

The PVY Risk Index Index  Not all species of aphid are equally efficient at transmitting PVY, some are better than others (green peach being the most efficient vector of PVY).  So, the total number of aphids in a trap don't necessarily reflect just how much vector pressure there is at that location. The PVY Vector Risk Index compares aphid numbers, incorporating their relative vector efficiency compared to the Queen of PVY vectors (green peach aphid!).  Using averaged reference comparisons from the literature, we multiply the number of each aphid species captured by its efficiency compared to Green Peach Aphid 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).

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

Trap Catches Identified to August 17th

Trap Catches Identified to August 17th

Greetings!

Aphid vector numbers are down a bit from last week...

We recovered a total of 236 aphids, 206 of which were vector species. We're still seeing high diversity in the species captured, recovering aphids from 12 different aphid species from 15 of the 16 sites reporting. Hoople (42), Sabin (33), Ada (29), Gully (22), and the site in Nebraska (26) led the counts in trap captures this week.

Green Peach Aphids were up a bit this week (a total of 5 from 4 different locations) and the grain aphid counts remain high.  Perham received a fair number of Soybean Aphids, suggesting they got a southerly or Southwesterly wind, bringing aphids up from the more heavily populated soybean fields in the south. The PVY Vector Risk Index remains low as the season wraps up.  Here's hoping that transfers into a low PVY year!

As always, keep on scouting!

Scouting for aphids in potatoes:

·         Select leaves from the lower to mid canopy.  Start at the edge of the field.
·         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.

The PVY Risk Index Index  Not all species of aphid are equally efficient at transmitting PVY, some are better than others (green peach being the most efficient vector of PVY).  So, the total number of aphids in a trap don't necessarily reflect just how much vector pressure there is at that location. The PVY Vector Risk Index compares aphid numbers, incorporating their relative vector efficiency compared to the Queen of PVY vectors (green peach aphid!).  Using averaged reference comparisons from the literature, we multiply the number of each aphid species captured by its efficiency compared to Green Peach Aphid 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).

Cumulative PVY Vector Risk Index Map to August 10th, 2018

Cumulative PVY Vector Risk Index Map for 2017 

(included for comparison)

Aphid Species Capture + PVY Risk - Week of August 5th, 2018

Total PVY Risk and Species Capture to August 10th, 2018

Aphid Alert 8-10-2018

Trap Catches Identified to August 10th

Greetings!

Looks like we have another big aphid week, folks!

We recovered a total of 301 aphids, 263 of which were vector species. In terms of aphid species, we are continuing to see a high diversity among those captured. This week, we recovered total of 15 different aphid species from 14 of the 16 sites reporting. We are seeing our heaviest flights in Grenora (80), Crookston (37), and Perham (36).

Last week, we recovered 130 total aphids, with the week before that topping off at 55 total aphids. Based on this trend, each week we are doubling the number of captured aphids. We saw this same trend occurring last summer towards the end of July to mid August, including a spike in cereal aphids. This does make sense, however, due to the maturing of grain which will lead to aphids seeking out better suited host plants.

We also recovered 2 Green Peach Aphids, one from Nebraska and one from Tappen.  Other aphid species captured included English Grain, Potato, Bird Cherry Oat, Pea, Buckthorn, Corn Leaf, Turnip, Greenbug, Thistle, Cowpea, Blackbean, Sunflower and Foxglove aphids. Soybean aphids were captured at Crookston (1), Nebraska (1), Perham (7), Sabin (1) and Staples (2) - so we're continuing to see movement across a broad area.

Josie noticed more winged aphids landing on her in the field, so had an idea that this week we'd see an increase in aphid numbers. This time of the year, there can be large flights coming into a field in search of better host plants, so population numbers can greatly increase in a matter of days. Some of our vector species, like Soybean aphids, don't colonize potatoes (deposit daughters on plants), so actually finding an aphid on a plant is rare compared to often a winged aphid may actually be visiting plants in the field (an advantage of suction traps, sucks 'em up as they're passing!)   Finding non-colonizing winged aphids on plants generally indicates there's a lot of movement going on.

As always, keep on scouting!

Scouting for aphids in potatoes:

·         Select leaves from the lower to mid canopy.  Start at the edge of the field.
·         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.

The PVY Risk Index Index  Not all species of aphid are equally efficient at transmitting PVY, some are better than others (green peach being the most efficient vector of PVY).  So, the total number of aphids in a trap don't necessarily reflect just how much vector pressure there is at that location. The PVY Vector Risk Index compares aphid numbers, incorporating their relative vector efficiency compared to the Queen of PVY vectors (green peach aphid!).  Using averaged reference comparisons from the literature, we multiply the number of each aphid species captured by its efficiency compared to Green Peach Aphid 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).

Cumulative PVY Vector Risk Index Map to August 10th, 2018

Cumulative PVY Vector Risk Index Map for 2017 

(included for comparison)

Aphid Species Capture + PVY Risk - Week of August 5th, 2018

Total PVY Risk and Species Capture to August 10th, 2018

Aphid Alert 8-03-2018

Trap Catches Identified to August 3rd

Greetings!

The vector numbers took a jump this week - aphids are starting to fly!  And, with apologies to Forrest Gump, this week's catch seemed to be summed up as: life is like a box of aphids, ya never know what yer gonna get....  

We recovered a total of 130 aphids,120 of which were vector species (15 different species!) from 13 of the 14 sites reporting. Sabin and Perham reported the heaviest flights with 32 and 24 vector aphids respectively.  

The number of species recovered in the traps this week was surprising, just about every vector aphid species we monitor was represented.  About 1/3 of the aphids captured were small grains aphids; no surprise there, even the latest planted grain is maturing and wheat harvest has begun, so grain aphids are seeking less senescent host plants. 

And the opening ceremonies for Sturgis are today (Aug 3) and our little 'biker bugs' are on the move (kudos again to Bruce Potter for coming up with the Sturgis Dispersal Event) and we're starting to see an increase in soybean aphid captures (although nothing like last year).  Soybean aphids were captured at Ballard (1), Crookston (1), Humboldt (1), Perham (1), Sabin (4) and Stephen (1) - so we're seeing movement across a broad area.  Populations in the soybean fields seems to remain low with only a few locations reporting populations at or above threshold.  

We also recovered 2 Green Peach Aphids, one from Sabin and one from Crookston.  Other aphids in the mix included Potato, Sunflower, Thistle, Cowpea, and Blackbean aphids.  Buckthorn aphids were also a frequent catch being recovered from 8 of the reporting sites.

This mixed assortment might reflect the colder nights we've been having lately.  In many species the movement from summer to overwintering hosts is triggered by temperature and photoperiod.  Cooler night temperatures can cause the development of a winged generation of adults whose purpose is to disperse back to the overwintering host.  Even in species that don't have their overwintering host here (such as green peach aphid), you'll still get those dispersal forms (aphids don't have access to Google Maps, they therefore have no idea their winter host isn't in the neighborhood).

So, numbers aren't that high but lots of different species out there - and they have to land somewhere.  So keep an eye on those fields...

As always, keep on scouting!

Scouting for aphids in potatoes:

·         Select leaves from the lower to mid canopy.  Start at the edge of the field.
·         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.

The PVY Risk Index Index  Not all species of aphid are equally efficient at transmitting PVY, some are better than others (green peach being the most efficient vector of PVY).  So, the total number of aphids in a trap don't necessarily reflect just how much vector pressure there is at that location. The PVY Vector Risk Index compares aphid numbers, incorporating their relative vector efficiency compared to the Queen of PVY vectors (green peach aphid!).  Using averaged reference comparisons from the literature, we multiply the number of each aphid species captured by its efficiency compared to Green Peach Aphid 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).

Cumulative PVY Vector Risk Index to August 03, 2018

Cumulative PVY Vector Risk Index for 2017

(Included for comparison)

Aphid Species Capture + PVY Risk - Week of July 29, 2018

Total PVY Risk and Species Capture to August 03, 2018

Aphid Alert July 27, 2018

Trap Catches Identified to July 27th

Greetings!

We are seeing a continuing trend of increased vector pressure this week; 43 aphid vectors (from 13 different species) were recovered from 9 of the 13 sites reporting this week. Sabin and Ada reported the heaviest flights with 12 and 9 vector aphids respectively.  

For the second week in a row, there were no Green Peach aphids collected.  We are, however, still seeing flights of grain aphid species. Soybean aphids were recovered from the traps at Ada and Ballard (1 from each location), There have been hotspots of soybean aphids reported from fields in several locations, including Crookston (although no local fields have been reported over threshold).  So keep monitoring for Soybean Aphids!

As always, keep on scouting!

Scouting for aphids in potatoes:

·         Select leaves from the lower to mid canopy.  Start at the edge of the field.
·         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.

The PVY Risk Index Index  Not all species of aphid are equally efficient at transmitting PVY, some are better than others (green peach being the most efficient vector of PVY).  So, the total number of aphids in a trap don't necessarily reflect just how much vector pressure there is at that location. The PVY Vector Risk Index compares aphid numbers, incorporating their relative vector efficiency compared to the Queen of PVY vectors (green peach aphid!).  Using averaged reference comparisons from the literature, we multiply the number of each aphid species captured by its efficiency compared to Green Peach Aphid 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).

Cumulative PVY Vector Risk Index to July 27, 2018

Cumulative PVY Vector Risk Index for 2017
(Included for comparison)

Aphid Species Capture + PVY Risk - Week of July 22, 2018

Total PVY Risk and Species Capture to July 27, 2018

Aphid Alert July 20, 2018

Trap Catches Identified to July 20th

Greetings!

There was a significant increase in aphid vectors this week; 51 aphid vectors (from 7 different species) were recovered from 11 of the 13 sites currently reporting.  This is a higher vector count than previously captured over the past 4 weeks COMBINED.  Ada and Crookston reported the heaviest flights with 20 and 10 vector aphids respectively.  

There were no Green Peach aphids collected this week but it appears that soybean aphids may be starting to fly (they recovered from Sabin and Ada in MN).  A few grain aphids were included in the mix as well.  As the grain matures and dries, the aphid population will respond by developing winged generations that will leave for, literally, greener fields....

These numbers have increased our PVY Risk Index in several locations and the appearance of Soybean aphid indicates that, if you haven't already started, it's time to start scouting your soybeans! The aphid season has begun, so keep your eyes open!

As always, keep on scouting!

Scouting for aphids in potatoes:

·         Select leaves from the lower to mid canopy.  Start at the edge of the field.
·         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.

The PVY Risk Index Index  Not all species of aphid are equally efficient at transmitting PVY, some are better than others (green peach being the most efficient vector of PVY).  So, the total number of aphids in a trap don't necessarily reflect just how much vector pressure there is at that location. The PVY Vector Risk Index compares aphid numbers, incorporating their relative vector efficiency compared to the Queen of PVY vectors (green peach aphid!).  Using averaged reference comparisons from the literature, we multiply the number of each aphid species captured by its efficiency compared to Green Peach Aphid 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).

Cumulative PVY Risk Index for the Week of July 16

Cumulative PVY Risk Index to the end of the 2017 Season For Comparison 
(Ie. How does the PVY Risk Index now compare to the end of last season?)

Weekly Capture 7-16

Total Capture + PVY Risk