The black and yellow mud dauber's nest comprises a series of cylindrical cells that are plastered over to form a smooth nest that may attain nearly the size of a human fist. After building a cell, the female wasp captures several spiders. The captured prey are stung and paralyzed before being placed in the nest, and then a single egg is deposited on the prey within each cell. The wasp then seals the cell with mud. After finishing a series of cells, she leaves and does not return. Eventually, the hatching larva will eat the prey and emerge from the nest. It has a black body with variable amount of yellow markings.
Length is 24 to 28 millimetres. Petiole is black, about half the length of the entire abdomen. The thorax shows various yellow markings, while the abdomen is normally black, with yellow propodeum (typical of females). The eyes are black, the antennae are black and the legs are yellow, with black trochanters and femurs. The wings are a tawny color.