Trap Catches Identified to July 31, 2020.

More sites captured aphids this week than last (12 of 19 reporting) but overall numbers are down a bit.  The season's vector numbers are low to this point and so the PVY Vector Risk Index remains low.  The numbers of sites reporting aphids though does mean we have winged aphids flying in the area.  

So, while aphid vector numbers may be low, they are well-distributed.  And considering the very low threshold for aphids in seed potatoes, scouting remains important.

Aphid Fact of the Week - Potato Virus Y can be acquired or transmitted by aphids vectors in less than a  minute, there is data to indicate some strains are more transmissible than others.  Virus particles are picked up on the mouth parts of winged aphid vectors when they probe potatoes to ascertain if the plant is a suitable host.  These aphids will eventually fly to and probe other potato plants, transmitting the virus particles to the new plant.  Because aphids will continue to probe plants as they cross a field, efficiently moving PVY inoculum around fields.  

 

If you have a field where Colorado Potato Beetle aren’t being controlled by insecticides, please let us know.  We’d like to get samples of that population to test for insecticide resistance.  Contact Ian MacRae at 218-280-9887.

As always, keep on scouting!

Click on any image below for full-scale version.

Cumulative PVY Vector Risk Index to July 24, 2020.

Cumulative PVY Vector Risk Index for 2019 (for comparison)

Aphid Species Capture and PVY Vector Risk Index for the week ending July 31, 2020

Cumulative Aphid Species Capture and PVY Vector Risk Index to July 31, 2020.