What kind of larve is this? Found in shed on terracotta pot in Northwest Oregon
They look like the nest and pupae of a mud dauber wasp; the black and yellow mud dauber is a common species to your area and elsewhere, though I can't personally identify the species clearly from the larvae themselves they certainly are consistent.

A nice view of the nest building process



These wasps have a characteristic very skinny abdomen, and they pack their nests with spiders before laying an egg there. They aren't typically a bother to people because they don't have any communal nest to defend, except for building nests on troublesome places like airplanes.