Trap Catches July 26 - Aug 02, 2024.
With 14 traps reporting, regional aphid vector numbers are very similar to those of last week and lower this point in 2023. Total number of vectors remained very much the same although there were differences in the species collected. There was one significant difference, the number of trap locations reporting Green Peach Aphid (GPA) has risen and the species was reported from several locations in the region. This may represent recent rain systems coming from the south. Along with similar numbers of aphid vectors, the PVY Vector Risk Index increased by an amount similar to last week. Still, this represents an increase in cumulative seasonal risk.
New locations reporting GPA this week included Becker, Crookston, Forest River and Perham. Lisbon, which has reported GPA already this season, captured 1 again this week as well. So, while the numbers of GPA are low at each location, it's regional distribution may be increasing. It appears the species is now present across most of the trapping area. Soybean aphids were numerous again this week as their late summer dispersal continues. Small grain aphids continue to be numerous as do cotton/melon aphids.
Temperatures are supposed to cool over the next week, but our nighttime lows will remain high enough that we will still be seeing aphid reproduction. While the rate of population development will slow, it will likely not cease. Aphid vector numbers may drop over the next few weeks, but the season is probably far from over. In addition, existing populations remain.
As stated last week, proactive measures, such as the use of crop oils, are recommended through to vine kill. As long as plants are green, they remain attractive to aphids that can vector inoculum. The use of the insecticides Fulfill (active ingredient = pymetrozine) and Beleaf (active ingredient = flonicamid) have been shown to decrease the spread of PVY and also to be beneficial when use in conjunction with crop oils such as Aphoil or JMS Stylet oil.
Bottom line, aphid numbers may (we hope!) drop over the next week, but they're still out there. So... Keep on scouting!
Aphid Species Capture and PVY Vector Risk Index for the week ending 7/26/2024
