Maybe there's more we can do about this?
Maybe you could put up wind sheet screens (hang bed sheets?) between that area and along a line in front of your hives for example for a few days, and have a closer water feeder that's in the opposite direction, or nearer your hives for that time period. I'm just throwing out ideas. (It would just look like laundry, and if you did maybe 4 or 5 in a row you'd only need a couple poles, some rope, and some stakes, maybe some tie down strings too, etc. Cheap fix., wouldn't need to be expensive but just divert some of the chemical downward to the ground.)
There has to be something you can do. What have others been doing for this?
Feel free to correct me, but I know none of us wants our bees to die. And this is likely to be a coming issue. Many people know have been talking about Army worm all over the place the last few months in agriculture. So it will likely could affect other beeks next year and the year after. They are really talking about army worm up north, and in China also.
Seems like a lot of risk to try nothing.