I think it does. I don't remember the bugs being nearly so bad back in the 1960s and 1970s as they are now where I live, but I never have to clean off the windshield of my car. When I was a youth we would fight for the privilege of squeegeeing the windshield at every gas fill-up. Now, it's hard to go out without drawing a cloud and even the dog wants to stay inside in the summer.

I suspect automobile aerodynamics play a bigger role in the windscreen index reduction than ecological destruction does.