Trap Catches Aug 16 - Aug 23, 2024.
With 9 trap locations reporting this week, the average number of vector aphid species recovered per location is slightly down from last week, but the change in species resulted in a similar level of PVY Vector Risk Index. Our numbers and PVY Vector Risk remain very close to the 2012-2023 average (see the chart below (see chart). The 12 year average of aphid vector populations in MN & ND indicates decreasing numbers through the end of August, but presence persists into September.
The only aphid species with a significant drop this week was soybean aphids. Most other vector species numbers were down slightly from last week with the exception of buckthorn, black bean, and potato aphids. The relative efficacies of soybean and the increasing species resulted in there being little change in the average PVY Vector Risk index from Aug 16 to Aug 23.
Some locations have already vine killed, but for those that have not, remember the adage - If leaves are green, by aphids they're seen! Yeah, corny, but true. As long as plant material is green and circulating, the plant is still susceptible to feeding by aphids and potential virus transmission.
Bottom line - aphid populations slightly decreased but the vector risk remained the same as last week. Meaning any field that is not yet vine killed remains susceptible to potential virus transmission...
Aphid Species Capture and PVY Vector Risk Index for the week ending 8/23/2024
