Trap Catches to July 22, 2022.
Aphid vector captures are up this week over last week, but still behind last year's numbers. This may be due to the wetter spring, which probably gave a boost to the fungal pathogens that often control aphid populations early in the year. Last year, the dry conditions likely precluded the establishment of these natural controls in many areas. This week, with most traps reporting, 74 vector aphids were recovered. Still no Green Peach Aphids, but cereal aphids are getting more numerous and other aphid species are showing up as well. With the increasing numbers, there was an increase in our regional PVY Vector Risk Index as well.
Most numerous were non-vector aphid species, indicating that the late July movement of aphids that we encounter in this region is underway. Soybean aphid numbers are slightly increasing, with 9 sites reporting low numbers. Cotton/Melon and Buckthorn aphids are both well-distributed across the region, Potato aphids were recovered at 6 locations as were Buckthorn aphids.
The PVY Vector Risk Index, which reflects the risk of PVY transmission within fields based on the relative effectiveness or the aphid species' ability to transmit the virus, also increased this week. Overall, our numbers are below where they were this time last year, but higher than 2020 or 2019.
It appears that our aphid numbers are following the standard pattern for our region, with populations starting to grow in mid-late July and peaking through August (see graph below). If this is the case, we'll see increasing aphid populations over the next few weeks.
So... Keep scouting, we'll keep counting...
Scouting for aphids in potatoes: