Boise area homes are often bombarded with these webs that are created. If not taken care of, these webs instead of catching prey, end up catching dirt and sand and mud. After a rainstorm or two, or your sprinklers hitting them, you have the beginnings of a material that will not extract itself from your siding and easily.
Especially from Masonary siding like stucco:
Though you can certainly sweep off or hose off these webs on a regular basis, it is far better in our opinion to do a regular perimeter pest control treatment to prevent these webs from forming in the first place.