Trap Catches Aug 09-Aug 16, 2024.

With 11 traps reporting, the average number of aphid vectors captured per trap across the region remained similar to last week. There were, however, some important differences; the average captures of small grain aphids was slightly below last weeks, while the numbers of soybean aphids increased, especially at two trap locations. Our PVY Vector counts and PVY Vector Risk Index values remain behind those of 2023, and we continue to see very similar levels as the 12-year average for number of vectors per trap and PVY Vector Risk Index. The top graph below is the current regional average PVY Vector data to 08/16/2024, the bottom graph is the average PVY Vector data from 2013-2023.  The X-axis is the ISO week of the year, the graphs are arranged so the ISO weeks correspond. 

Soybean aphids continue to increase as their seasonal dispersal continues. This will likely continue until our nightly temperatures drop into the 40'sF.  Green peach aphid captures increased over last week, and were captured from 4 locations, with the trap at Becker, MN  returning 6 of the wee beasties. Small grain aphid numbers were lower than last week, which is not surprising given many locations are already harvesting wheat. As with last week, many of the aphid species recovered do not colonize potato. So, we'll keep counting for now.

Bottom line - The aphid populations were off to a slow start but we are now very close to the average 2012-2023 averages. The recent rains in some of our locations may slow aphid population growth but the 12-year average population declines don't occur until the end of the month.  

Click on any image below for full-scale version.

Cumulative PVY Vector Risk Index to 8/09/2024

Cumulative PVY Vector Risk Index to 8/11/2023 for Comparison

Aphid Species Capture and PVY Vector Risk Index for the week ending 8/16/2024

Cumulative Aphid Species Capture and PVY Vector Risk Index to 8/16/24