I keep my bumper Zaino'd real good so any buds just wipe right off with soap (Z7) and water really easy.
On cars that I detail that do not have a good coat of protection I soak them with soap and water and then use a micro fiber applicator to scrub them off. The applicator is called the power scrubber and is from properautocare.com and work real well with no scratching at all. Those mesh like bug removers work well also.
An ounce of prevention is worth a pound of cure. I will usually remove them right away with a wet sponge and then dry the bumper as the longer they are on there the harder they get to remove. Bug guts are also very acidic and will eventually etch your paint if left on the bumper long enough.
