Being said, the conditions that favor rapid aphid development are just the conditions we have now. There were some fields in the Granite area where I was able to find aphids on every plant I sampled but at low levels. I suspect these fields will be at treatment levels by at least next week. Most fields only had a small portion of the sampled plants infested and will most likely be a week to 10 days behind the others.
The field where I found the plants in the above picture was in MN Falls township not far from the valley. Outside of the one or two 'hot spots' I found there were no other aphids found, so if you are doing some checking and don't find anything you may not be as well off as you would think. It does take some walking to fully grasp the field.
Outside of aphids, I do see some weeds in the fields yet - mostly waterhemp. Controlling waterhemp this time of year is a hit or miss proposition and at the height and maturity of the weeds now, mostly miss. Also remember that by label glyphosates can only be applied up to the R2 growth stage and we are now there.
Interestingly, according to the records kept at the Southwestern Research and Outreach center in Lamberton, we are only 75 GDU's behind the historic average