Trap Catches to July 7-14, 2023.
With ten traps reporting in, aphid captures remain very low; only 12 vector aphids were captured. We are starting to see the beginning of grain aphid flights. The first soybean aphid was also recovered this week; not surprising given local populations lead us to we believe soybean aphids successfully overwintered in northern Minnesota and North Dakota this year.
The species of vectors that were captured this past week were generally less effective vectors and so the PVY Vector Risk Index remains low. At this point last year capture numbers at several sites were higher and their and PVY Vector Risk values were almost twice what they are now (see below).
Warmer weather is predicted for the upcoming week, so aphid flights might heat up as well. We'll see what the traps capture...
You keep scouting and we'll keep counting.
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.
Click on any image below for full-scale version.
Cumulative PVY Vector Risk Index to 7/7/2023
Cumulative PVY Vector Risk Index to 7/15/2022 for Comparison
Aphid Species Capture and PVY Vector Risk Index for the week ending 7/14/2023
Cumulative Aphid Species Capture and PVY Vector Risk Index to 7/14/2023
