Trap Catches Identified to July 24, 2020.
Even though aphid numbers increased this week, they remain low with 24 vectors recovered from 9 sites of the 17 sites reporting this week. We started to recover soybean aphids from a number of sites as well. All the data's below in the tables.
PVY Vector Risk Index is now lower than this time last year. Small grains continue to mature and we have not yet seen a flight of cereal aphids, so this may change in the next week or two. Overall, however, the aphid numbers appear relatively low this year..
But the presence of winged aphids does signal the continued need for scouting, we do have movement of aphids into potatoes. If you're not already, it's time to be scouting seed (and commercial) potatoes for aphids.
Many of the species we're recovering are non-colonizing species, meaning they may not show up when sampling potato leaves. But their habit of moving through fields, probing plants to assess host suitability means they are still a problem!.
Aphid Fact of the Week - There are two different types of adult aphids; winged and non-winged (referred to as alate and apterous forms respectively). The winged aphids are dispersal forms. In summer, they're the individuals who leave colonies that are becoming stressed from densities or decreasing food quality. In the late season, winged aphdis will return to overwintering hosts. The non-winged aphids are colony builders, they feed on host plants, give birth to live daughters and increase the size of the colony. A winged aphid's daughters will always be non-winged.
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 24, 2020
Cumulative Aphid Species Capture and PVY Vector Risk Index to July 24, 2020.
