Solitary wasps whose common name comes from the mud nests they construct out of mud.  Mud daubers have slender, threadlike waists.  Typically ½ to 1 inch in length, these wasps are typically very placid unless handled roughly.  Nests are often located in barns, garages and under the eaves of houses in urban setting where as they tend to be under rock ledges, cave entrances or other sheltered places in natural settings.  Female mud daubers carry mud from puddles and other water sources to the nest site to construct each cell of the nest.  On average it takes approximately one hour to construct a single cell.   Some have noted that mud daubers make a “singing” sound while they construct their nests.  Eggs are laid inside each cell and food in the form of a paralyzed spider is placed in each cell by the female prior to the cell being sealed. Black widows and crab spiders are favorites of several species of mud dauber. Overwintering mud daubers spend the winter as immature individuals in the nest. Mud daubers reserve stinging for their prey and rarely sting humans.  They do not have tendencies of defending their nest from humans like other social wasps. Although their nests are sometimes considered unsightly, mud daubers are beneficial forms of spider control and therefore many residents are willing to tolerate the nests.

Species Identification:

Black-and-yellow Mud Dauber – Nest cells are constructed side by side or on top of one another.  The finished nest is rounded in shape and can be as large as the size of a fist.  Two generations are produced each summer.

Organ Pipe Mud Dauber – Black bodied with blue wings, this mud dauber has white markings on the hind legs that resemble stockings.  Nest cells are vertical or parallel in rows; the finished nest resembles a pipe organ, which is where their common name derives from.  Males are among only a few species to stay at the nest.  The male will “stand guard” at the nest to deter potential parasitizing insects that may otherwise sneak in while the female is away.  Females are responsible for collecting spiders and nest construction.  Mating occurs frequently as the female visits the nest site.

Blue Mud Dauber – Some might call this species lazy, others would consider it resourceful.  The blue mud dauber does not construct her own nest; rather she carries water to an old nest abandoned by another mud dauber, softens the mud and remodels the nest.  This species collects the largest quantity of black widow spiders and is often a welcomed sight where black widows are plentiful.