Sceliphron caementarium, also known as the yellow-legged mud-dauber wasp, black-and-yellow mud dauber (within the US), or black-waisted mud-dauber (outside of the US), is a species of sphecid wasp. There are some 30 other species of Sceliphron that occur throughout the world, though in appearance and habits they are quite similar to S. caementarium. S. caementarium is widespread in Canada, the United States, Central America and the West Indies, and has been introduced to many Pacific Islands (including Australia, Hawaii, and Japan), Peru and Europe, where it has become established in some countries of the Mediterranean Basin (Croatia, France and Corsica, Italy, Cyprus, Malta, the Canary Islands, and Madeira) and Austria, and Ukraine.
