Most of the wild forage here has been displaced by crops. It always pains me to see the hedge rows and old fence rows dozed in and cleaned up to gain that extra couple acres here and there in with which to plant more corn or beans.
I used to hunt those valleys, hedge rows and fence lines. trees and weeds grew in them and the coons loved to run them.. That began to change, and as I went looking for places to turn my hounds loose, all i found were doze piles.. places those same raccoons could safely hide. if my dogs "treed" in one of those piles there was nothing for it but to pull them off and go elsewhere... The sad story for the bees, is that it also removes the blooming plants that grew in those places. In the last ten years I can only guess that better than four hundred acres within my bees foraging radius has been replaced with corn and beans. Every year I see more of those big piles of twisted up fence and tree trunks....
As for the spray? Its mostly round up, and it seems to have no effect on the fence rows at mine or my fathers land. I spend several days each summer running the bush hog along the fence lines to keep the trees cut down, the goldenrod, aster and other wild blooming plants bounce right back within a few days.