The only bugs I've ever really seen on my out door bunnies were spiders and beetles, and flying things that got trapped in the plastic that shields them from rain. I have more fly problems with my indoor bunnies than outdoor ones, as far as I know.
I also suggest mosquito netting over the run, where she can't chew it up of course. I'm also planning on getting fly traps & mosquito repellent to hang around my cages for the summer. I wouldn't recommend sprays or such, only things that have no chance to find their way into little bunny mouths.