Trap Catches July 03, 2025.
The number of aphid species in the traps rose slightly over last week, but most were non-vector species. With 9 traps reporting, traps recovered a total of 50 aphids, only 5 of which were vectors. Having said that, we are slightly ahead of where we were on aphids counts this time last year. In 2024, the week after July 4 had a noticeable rise in vector flight, so we'll see what comes our way... In any case, aphids are flying and our rising temperatures will increase feeding rates and subsequent reproduction, we are rapidly getting into the aphid growth days of summer.
Vector species this week consisted mostly of corn leaf aphid, but potato and English grain aphids were also recovered. Keep scouting and checking predictive sites!
Have a great Fourth of July weekend!
The usual reminder:
- keep scouting; aphids can establish early after potatoes are up. Field scouting is less effective at finding aphid vector species that don't colonize potatoes. While these species will enter potato fields and probe plants, they can't survive on potatoes, consequently they'll keep moving through the field, sampling additional plants and spreading inoculum in the field. Remember to check predictive sites like this one and University of Wisconsin's weather based Vegetable Disease & Insect Forecasting site,(https://agweather.cals.wisc.edu/vdifn) which uses current weather data and historical populations as a predictor of current aphid vector populations. These will give you a better idea of the potential presence of non-colonizing aphids.
- the research literature reports that the use of crop oils is the most consistent post-planting technique in preventing transmission of PVY and it can be improved with the addition of the insecticide Lambda-Cyhalothrin.
- most of the research indicates that insecticides on their own are not effective enough at suppressing PVY transmission, but are still useful parts of your management program. Treating fields with one of the anti-feeding insecticides such as Sivanto Prime, Sefina or Transform to control colonizing aphids, such as green peach, potato, or cotton melon aphids, can be beneficial
- aphids preferentially first colonize fields at the edge. Using border crops in the headlands may decrease aphid colonization. But if using a border crop, it's a good idea to use treated seed to prevent the development of potential vector species in that border. And to include those border crops when treating the field for colonizing aphids.
Happy scouting and have a safe and happy Fourth!
Click on any image below for full-scale version.
Cumulative PVY Risk Index by Site to 6/27/2025
Cumulative PVY Vector Risk Index by Site to 7/05/2024 for Comparison
Aphid Species Capture and PVY Vector Risk Index for the week ending 7/03/2025
Cumulative Aphid Species Capture and PVY Vector Risk Index to 7/03/2025
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