What pollinates apples, besides bees?

I'd like to plant apple trees -- only a couple -- in my yard.

If I must have honeybees, then I'll look into the details of that.
But honeybees, who wander far, are likely to run into insecticides. I
live in a city, next to lots of neighbors and even a school. There's
no way to prevent them all from using bug-killer.

Thank you!

Ted Shoemaker