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Black-and-Yellow Mud Dauber

Black-and-Yellow Mud Dauber with a mud pellet.
Black-and-Yellow Mud Dauber with a mud pellet. (Photo: © 2019, Donna and Sophia Burgess. Used with permission.)

Dr. Art Evans and VPM radio producer Steve Clark talk about a photo of a black-and-yellow mud dauber sent in by WBY? listeners Donna and Sophia Burgess.

More on the black-and-yellow mud dauber: http://entnemdept.ufl.edu/creatures/MISC/WASPS/Sceliphron_caementarium.htm

The blue mud wasp: https://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/blue-mud-wasp.shtml


Steve Clark:  I'm Steve Clark with Dr. Art Evans, entomologist, and this is What’s Bugging You.  When I was a kid, there was a wasp that we would see all the time. It was a mud dauber.

Art Evans:  Mmmhmm, oh. 

Clark:  I grew up near the mud flats, so a prime occupant of that place was this wasp, kind of a blue-black color.

Evans:  Right, oh okay.

Clark:  And it had a flitting sort of jumping dance that it did.  But I never saw what they did, other than dig into a little hole.

Evans:  Well hold that thought. We'll get back to it. It just so happens that one of our listeners and her daughter, Donna and Sophia Burgess, sent me a beautiful photograph of a black-and-yellow mud dauber that was sitting on the windshield of their car. And you can see it clearly holding the mud pellet. And I thought, “This is great. We'll have to talk about this.”  Of course I think everyone's familiar with the mud nest that these wasps make. It looks like sort of a dirt clod that's up under the eaves, and these wasps will carry mud from a pond or the edge of a pond and then build into it chambers that they fill with living, but paralyzed spiders. And then they lay their eggs inside these tunnels with the spiders.  The eggs hatch and feed on the spiders, and so it goes.  Now these wasps are not aggressive. The only way you're going to get stung by one is if you actually grab one. And I think most of us know better than grabbing a wasp. [laughing] So there's really no reason to remove them or panic if you see them around. But there's an interesting little side story and this is what brings us back to your wasp, and that is the blue mud wasp.  Some people call it a blue mud dauber.  They repurpose the nests of the black-and-yellow mud dauber.  Instead of mud, they carry water to the mud nest of the black-and-yellow mud dauber to soften up the dried mud, and then they walk into the tunnels, and they throw out all the spiders and the larvae of that wasp and replace it with their own. [laughing]

Clark:  Now those were perfectly good prey in there, right?

Evans:  Yes, but it's the wrong food for their young.  The black-and-yellow mud daubers prey primarily on orb weavers, the ones that have the two dimensional webs.  They're easy to pluck out of the webs. Whereas the blue mud wasp will go after different spiders that make messier webs, and they'll use those.  So they use an entirely different brand of spider, if you will, for the provisions they set aside for their young. [laughing]

Clark:  How long does it take for the young to develop?

Evans:  That's a good question. I'm not sure. As far as I know they have one generation produced per summer, but don't hold me to that.  And of course there's another mud dauber that many of our listeners will be familiar with, the organ pipe mud daubers.  And those are the ones that have the tubes; they're placed side by side.  And you'll see the holes coming out of the sides of those tubes, and those are the emergence holes of the mature wasp that develop within.

Clark:  Are they vertical?

Evans:  Yes, but a lot of people think that they need to be removed, and there's really no reason for it. These wasps aren't defensive. They don't defend their nests like a social wasp does. These are all solitary wasps, and the only way that you're going to have a bad experience with one is if you actually grab one, and that sort of behavior is easy to avoid. Both of these wasps, when they're not building their nests are busy visiting flowers. They feed on nectar for their own sustenance, and so you'll find them buzzing along with bees and other insects in your native plant garden

Clark:  Dr. Art Evans is a research associate at the Virginia Museum of Natural History.  You’ll find photos, audio, and links to the museum and Art’s Facebook page at vpm.org/bugs.


Dr. Arthur V. Evans teams up with VPM Radio producer Steve Clark for a weekly feature, “What’s Bugging You?,” which airs during NPR’s Morning Edition. The program takes its name from another of Evans’ books “What’s Bugging You – A Fond Look at the Animals We Love to Hate.”

Tune in each Tuesday at 8:45 a.m. or at 5:44 p.m. on VPM News