Bugs are everywhere, but we do need to worry about invasive foreign types. Fire ants supposedly came here in a potted plant, and they've been devastating to native animals as well as people. Pesticides are useful, but can be dangerous. Moderation. Accept the bugs we can, squirt the ones we can't.
My (still) worthless ex-boyfriend said not to worry about the spiders and mites. He works in invasive species and really didn't seem concerned about this, so just check for bugs before you buy.
At least you know that the bananas didn't have so much pesticide on them that the spiders and mites...