Trap Catches to July 12 - July 19, 2024.
With 15 traps reporting, aphid vector numbers are still relatively low, but average aphid captures per trap did increase significantly over last week. Aphid vector numbers jumped by a factor of 4 and the regional PVY Vector Risk Index value almost doubled. Remember though, because we were at low populations last week, we remain at relatively low numbers. But numbers seem to be tracking up at this point.
A number of species increased across the region this week. Soybean aphids have started to increase in most locations as have small grain aphids. Potato aphids and cotton melon aphid numbers both increased this past week, as did the number of buckthorn aphids. Green peach aphid was again present in one trap location.
As the warmer weather continues and alternate crop hosts mature, especially small grains, vector numbers will likely continue to rise over the next several weeks. If not already started, proactive measures, such as the use of crop oils, should be considered and implemented. Research data* from Canadian researchers indicates the addition of an insecticide with the active ingredient Lambda-Cyhalothrin in crop oil applications may improve management of PVY spread. If implementing this tactic, keep in mind the dynamics of our aphid populations tend to later in the season than where that research was conducted. See the graph below for the average vector capture per trap and average PVY Vector Risk Index for 2012-2022.
Bottom line, aphid numbers are increasing and will likely continue to do so. So... Keep on scouting!
*MacKenzie, T.D., Lavoie, J., Nie, X. and Singh, M., 2017. Effectiveness of combined use of mineral oil and insecticide spray in reducing Potato virus Y (PVY) spread under field conditions in New Brunswick, Canada. American Journal of Potato Research, 94, pp.70-80.
