Yeah, as far as Black Widows, they really aren't much to worry about. Even the most urban areas of Sacramento still have plenty of places where you'll find them, but they rarely come inside for whatever reason. I don't work in the fields or live in the woods or anything remotely out of the ordinary for a typical city-dweller, but I've seen hundreds if not thousands of them in my lifetime. Never been bit, never had an animal bit, never even known someone with an animal bit that I can remember. Not saying you shouldn't be careful, but it's like the earthquakes...the one time in 50 years one fucks with you, it sucks, but otherwise there is nothing to worry about.
That giant fucking wasp on the other hand...Goddamn, I can't stand the giant fuzzy bees, which typically aren't very aggressive at all but still terrify the fuck out of me. I can't imagine seeing something like that wasp flying at me without letting at least a little pee out.