Mud daubers are familiar wasps with narrow or threadlike waists. These solitary wasps belong to a number of related groups, but we call them “mud daubers” because they all build their nests out of mud. You can identify the different species by coloration and by the distinctive nest architecture.
Three species are especially common in Missouri:
- The black and yellow mud dauber (Sceliphron caementarium) constructs nest cells side by side or on top of one another; the final product is rounded and about the size of a lemon or a fist.
- The pipe organ mud dauber (Trypoxylon politum) is black with blue wings, with white “stockings” on the hind legs. It makes vertical, parallel rows of cells; the finished product looks like a pipe organ.
- The blue mud wasp (Chalybion californicum) is a pretty metallic blue; it does not build nests but instead reuses those of one of the other species. Instead of mud, it carries water, which it uses to soften and remodel the mud of the older nests.
Habitat and Conservation
Nests are often seen in barns, garages, and the eaves of houses. Howard Ensign Evans wrote, "the passing of the outdoor privy was a sad day" for mud daubers!
In nature, nests are built in cave entrances, under rock overhangs, and in similar places.
A female carries mud balls from a puddle to the nest site; a cell takes about an hour to construct. Their buzzy "singing" while applying mud to a nest is one of many interesting habits and behaviors you can enjoy.
Most people would call these insects beneficial, because they would agree that any natural remedy that reduces black widows around the home is a good thing. Because blue mud wasps (which specialize in hunting black widows) need the old nests of the other two species, consider allowing any mud daubers to build nests where you can tolerate them. Mud daubers reserve their sting only for prey and rarely sting humans (they do so only if handled roughly).
Although other types of wasps may also build nests on your house, note that some are solitary and some are social. The solitary species, such as mud daubers, do not defend their nests like paper wasps, yellow jackets, and other social species.