Yup.. I'm 50 and I will attest there is NO DOUBT insects populations have declined. It's crazy.

Fellow biker here, with as small a windshield as I can stand (meaning my helmet stands above the windshield. I still carry a can of Honda Spray Cleaner and Polish in the tank bag for scrubbing the face shield on the helmet, as well as the windshield. I used to go through several cans a year. Now, for the same miles ridden, a can might last over a year. The one variable is the bike, but I've owned a variety of bikes over the decades I've been riding, and only in the last 10 years or so did I have to cut back on my standing order of cleaner.