Mudwoman

Kelly’s Field Notes

Common Name: Mud Dauber

Order: Hymenoptera

Family: Sphecidae, Crabronidae

Genus: There are a lot of differing opinions on the taxonomy of Sphecidae, but there are either 19 or 20 genera within this family. There are over 200 genera within Crabronidae. Not all of the wasps in either family are mud daubers (Ito et al., 2015; Shayestehfar et al., 2014). To my knowledge, there are only 3 genera of mud daubers - Sceliphron, Chalybion, Trypoxylon, though not every species within these genera are mud daubers.

Species: There are between 660-736 described species in Sphecidae. There are more than 9,000 species of wasp in family Crabronidae (Saini et al., 2023). We will be focusing on a paraphyletic grouping that shares a common name and nest-building behaviors. 

Notable species:

• Yellow-legged mud dauber, black-and-yellow mud dauber (Sceliphron caementarium) - family Sphecidae, located throughout Central and North America as well as parts of South America, and western Europe.

• Common blue mud dauber (Chalybion californicum) - family Sphecidae, located throughout Central and North America as well as parts of South America, and western Europe.

• Organ pipe mud dauber (Trypoxylon politum) - family Cradbronidae, found in the eastern United states. 

Description: 

Mud daubers are long slender waisted wasps (about 2.5 cm in length or 1 inch). They come in your classic wasp colors of black and yellow, or all black, but also an iridescent blue (Chalybion californicum). It has been speculated that the narrow waist (the petiole) allows the hemolymph running through the dorsal blood vessel to warm up quickly due to its exposure to the environment. The dorsal blood vessel also runs through the flight muscles. Another speculative reason is the thin petiole makes it easier for the wasp to bend to either sting or oviposit (lay eggs).

Named for their nest building, mud daubers use mud to fashion individual cells clumped together in a variety of shapes. In the wild they nest in cave entrances or inside tree hollows, but those living with humans may nest on the sides of our house, on the ceiling of the porch, in a cavity leading from the outside of the house inside or udner bridges and other man-made structures. For example, yellow-legged mud daubers (Sceliphron caementarium) create rounded lumpy nests, common blue mud dauber (Chalybion californicum) create lumpy non-uniformed nests, and the organ pipe mud dauber (Trypoxylon politum) creates long tube or pipe shaped nests (Missouri Department of Conservation, 2025). The common blue mud dauber will often reuse another mud dauber’s nest, sometimes still occupied. They will pull out any remaining larvae and spiders, and take over the nest. Pipe organ mud daubers sometimes do this or two females may share a nest (Arthropod Museum, 2025).

Life Cycle: 

Mud daubers are solitary wasps! After mating, the female will create a nest out of mud after mating. She picks the mud up in her mandibles then passes it to her forelegs to carry back the nest. She makes several chambers to lay a single egg into after she has stuffed it full of paralyzed spiders. They can create up to 25 individual cells. Depending on the species, she might add only a few or up to 40. The spiders remain alive and paralyzed, eaten alive by the larvae. Eggs take about 2 days to hatch. Once hatched the larvae remain in their nests overwinter and pupate within the mud chamber. 

Adults mud daubers, like most wasps, feed on nectar. Spiders are for the larvae only!

Organ pipe mud dauber males guard the nest as it is an enticing space for parasites. This is rare for Hymenopteran, excluding some eusocial species. He will also continue to mate with her each time she comes back with more mud. The cuckoo wasp, Chrysis angolensis, will often try to get past the male to lay an egg in a mud dauber nest (Marchiori, 2022).

Super Powers:

• Flight - like most wasps, flight is a basic super power.

• Sting - mud dauber stings are not as painful as a bee sting and harmless unless you are allergic (or a spider). Mud dauber stings are not medically significant. In general, solitary wasps are less interested in stinging mammals than eusocial species; they don’t have backup so it’s not a fight they can win!

• Paralyzer - mud dauber wasps use their stingers to paralyze spiders then bring them back to their nests. Once there the wasp egg will hatch and the larva will eat the still living spider.

• Mud Manipulation - sculpting a protective shield out of mud, our hero can protect itself against any foe.

• Stealth Mode - mud daubers are solitary wasps, operating solo and quietly.

• Anti-Spider Sense - mud daubers hover near spider webs searching for prey. Different species hunt different types of spiders: yellow-legged mud daubers hunt crab spiders, common blue mud daubers hunt black widows, and organ pipe mud daubers hunt orbweavers (Missouri Department of Conservation, 2025)

• Strength - after paralyzing a spider the mud dauber must haul it all the way back to its mud nest, sometimes the spiders weigh more than the wasps!

• Mimicry - many mud dauber species have Müllerian mimicry with other stinging hymenopterans. These shared colors and patterns reduce predation.

Mud Daubers And Humans:

• Mud daubers have been responsible for two fatal plane crashes (Birgenair Flight 301, 1966; Florida Commuter Airlines Flight 65, 1980) and one unscheduled landing to avoid cabin overpressurization (Gulfstream G-IV, 2015) (National Transportation Safety Board, 1980; Flight Safety Foundation, 2025). The fatal crashes had mud dauber nests inside the pilot tube of the plane, which is responsible for measuring airspeed.

• Mud daubers are great to have around your garden. Their sting is mild and who doesn’t want fewer black widows on your property? As with many solitary Hymenoptera, they are not aggressive. They also do not defend their nests (Missouri Department of Conservation, 2025).

References:

Flight Safety Foundation. “Accident Boeing 757-225 TC-GEN, Tuesday 6 February 1996.” Flightsafety.org, 2025, asn.flightsafety.org/asndb/324523.

Flight Safety Foundation. “Accident Gulfstream G-IV N450KK, Friday 10 April 2015.” Flightsafety.org, 2015, asn.flightsafety.org/wikibase/320315. Accessed 8 Aug. 2025.

Ito, Masato, et al. "Sphecid wasp larvae feeding on large-sized cockroaches in a dead wood cavity." Journal of Hymenoptera Research 46 (2015): 173-177.

Marchiori, Carlos Henrique. "Study of the reproductive behavior and parasitism of the Sphecidae Family (Insecta: Hymenoptera)." Open Access Research Journal of Biology and Pharmacy 5.2 (2022): 051-081.

“Mud Daubers.” Missouri Department of Conservation, 2025, mdc.mo.gov/discover-nature/field-guide/mud-daubers.

National Transportation Safety Board. “Aircraft Incident Report: Florida Commuter Airlines, Inc. Douglas DC-3, N75KW Grand Bahama Island, Bahamas September 12, 1980. United States Government (1980): 1-26.

“Organ-Pipe Mud-Daubers.” Arthropod Museum, 2025, arthropod.uark.edu/organ-pipe-mud-daubers/.

Saini, Varun, Debjani Dey, and Narottam Kumar Meena. "Diversity of Crabronid wasp fauna (Hymenoptera: Crabronidae: Crabronini) in the spice ecosystem." Journal of Entomological Research 47.4 (2023): 797-800.

Shayestehfar, Alireza, et al. "Biosystematic study of Sphecidae family in Golpayegan-Isfahan province, Iran." Research in Zoology 4.1 (2014): 20-28.