Mud Daubers

Common Name: Mud daubers

Introduction: This group of wasps gets its common name from the fact that they construct their nests of mud. They are typically nuisance pests. Mud daubers are found throughout the United States.

Recognition: Adult mud daubers are 3/4 to 1 inch long and slender. The body color is usually black or metallic bluish-black with pale to yellow markings. The wings may be clear or dark. The abdomen is slender or having a stalked waist.

Similar Wasps:

1. Thread-waisted wasps do not make mud nests and are more commonly observed on flowers.
2. Paper wasps construct paper nests resembling gray umbrellas attached by a stalk to a sheltered or concealed surface.
3. Some potter wasps are similar to mud daubers in color but do not have a stalk-waisted abdomen or gradually tapered abdomen. Their mud nests are single-celled and resemble inverted clay pots.

Biology: Mud daubers are solitary wasps; they are not social and do not live in colonies. Mud daubers overwinter as full-grown larvae, pupate in spring, and emerge shortly thereafter. Females construct nests of mud. Many short mud tubes/cells, usually about 1inch long, are constructed side-by-side or end-to-end. Each cell is provisioned with several spiders that have been stung and paralyzed by the wasps’ venom. The female wasp deposits an egg on the first spider that is stuffed into each cell. Eventually the grouping of cells is about 3 to 4 inches across and is entirely plastered over with mud. The female then selects another site and starts over. A larva can complete its development in about 3 weeks, then spins a silken cocoon but does not pupate until the following spring. Females typically provision their cells with only one kind of spiders. Mud daubers do not defend their nest, and only rarely sting (i.e., in self-defense, if grasped).

Habits: Mud daubers typically select a sheltered site to build their mud tubes. Favorite sites include rustic wood siding, masonry walls, under eaves, porch ceilings, in garages, attics, open sheds and barns.

Nests typically exhibit round holes in them as the wasps emerge. This indicates that the nest is probably old and inactive after springtime.

Mechanical Protection Measures: One can simply scrape the nests from attachment surfaces using a scraper or putty knife and sweep the mud fragments from any paved surfaces below. The non-aggressive female wasps will not attack and rarely rebuild nests in the same location from which they were just removed during the same year.

Wingate Professional Procedures: Mud daubers are beneficial insects and help control spiders. If the nests are located near human activity, then control may be warranted. A Wingate technician can remove the nests using a scraper attached to an extension handle. Mud dauber nests can be removed from buildings without use of insecticides. However, future activity can be discouraged in a given area by the application of a residual insecticide. The nests themselves should not be sprayed with a liquid insecticide because this will create a muddy mess on and beneath the attachment sites.