Friday, June 27, 2014

Trap Catches Identified up to June 27*

Here's the trap catch up to June 27.

All of the traps are now in and hopefully all locations will start sending in their weekly catch by next week.

So fqar this summer, aphid catches remain low and most of what we're finding in several locations are non-vector species (these are aphid species which can be found in potato, but do NOT transmit PVY - so no danger there).  We include the numbers of non-vectors just to let you know that aphids are dispersing during this time period (and that the traps are working!).

Forest River in ND had the highest trap catches with 5 vector species.  We haven't found any green peach aphids or soybean aphids in any location so far this year but it's early yet.  This week Black bean aphid was by far the most common vector species found in the traps.

As in the past two years, we’ll be supplying the data in both tabular and graphic formats.  This season has had a slow start, with late planting.  There have been a couple of wind events that could possibly bring aphid vectors into the region from the south.  Keep an eye on fields!

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.