Mud dauber is a messy nester but no threat

A black and yellow mud dauber — our most common “dirt dobber” — readies to pack a ball of mud back to a nest to build nursery chambers.

Here are three foremost questions of and for mankind:

1. What is the meaning of life?

2. Do you want fries with that?

3. Can a dirt dobber sting me?

You really must answer the first two for yourself. But for question three, the correct response is: Some can but they almost never do. More on that later.

Our insects here are commonly called dirt dobbers, but they more properly are identified as mud daubers — and they do daub mud. They are cousins of the wasp family, but they have significant differences. Most are up to about an inch long, but unlike other wasps, they have a skinny, thread-like connector between thorax and abdomen.

The big lifestyle difference between mud daubers and the wasps that strike fear in many hearts is that the mud daubers are solitary insects and social wasps are colony nesters. A mud dauber nest is the domain of a lone mild-mannered female dauber; a wasp nest is the home to several or dozens of surly, defensive insects.

There are multiple mud dauber species, and hereabouts there are three species that most commonly are experienced. Most routine probably is the brown and yellow mud dauber, which looks most like a skinny wasp.

This insect has a black body with yellow markings on its legs and body. Its translucent wings are brown, and seeing it in flight, an observer is left with the impression that much of the bug is brown. Many people can’t tell a black and yellow mud dauber from a wasp, overlooking the ultra-skinny body connection that should be a dead giveaway.

The pipe organ mud dauber is black all over with translucent blue wings.

Meanwhile, the blue mud dauber, maybe a touch smaller than the other most common varieties, is a dark metallic blue color.

The black and yellow species and the pipe organ mud dauber build two different kinds of nests. The black/yellow brings back mud, one tiny ball at a time, to form nest cells in a collective dirt structure that comes out as a clump or a ball up the size of a fist.

The pipe organ mud dauber builds side-by-side, vertical tubes of mud that come out looking like the sound chambers of a pipe organ.

The blue mud dauber does not build its own nest from scratch, but instead it hauls drops of water that it uses to soften the cells of abandoned nests of yellow and black, and pipe organ mud daubers. The blue doesn’t build but rather remodels, reshaping old nests, to suit its tastes.

When a nest cell is finished, the female mud dauber lays an egg in there. But before sealing it, she stocks the nursery with baby food. The momma dauber does possess a stinger. She hunts down a few spiders, stinging each. The spiders are not killed but rather paralyzed.

The stung spiders are kept alive for a grisly purpose. They are airlifted back to the nest and cached into the egg chamber to be eaten by the larval mud dauber that hatches from the egg in that cell. When enough zombified spiders are stored in the pantry, the mother mud dauber seals the chamber.

Most mud dauber species produce young that hatch and dine on spiders as they overwinter in their nursery nest. They then emerge as new adults in the spring.

If you want to verify the process, find a mud dauber nest that is active — that is, find one that is intact and chambers still sealed. Break it open and, along with developing dauber, you’ll find a collection of spiders destined to feed the juveniles.

An interesting side note is that some species of mud daubers are heavy users of black widow spiders to stock nest chambers. Blue mud daubers almost specialize in black widow spiders.

Mud dauber nests stuck on accessible equipment, tools and such in outbuildings, garages, etc., grow annoying, but the plus to remember is that resident mud daubers are always working on the spider population. Especially when poisonous black widows are being targeted, it makes putting up with the messy daubers’ nests a little easier.

And regarding the most common concern, if you are messing around near a mud dauber’s nest, you’re not going to get stung by the resident insect. There won’t be a bunch of them guarding the nest. Even the one female that is mistress of the nest won’t guard it.

Mud daubers are neither defensive nor aggressive. Only the female has a stinger, but that is almost never used except to paralyze spiders. A human is unlikely to provoke a sting unless the mother dauber is taken into hand and treated rudely. Unless you catch one, there is virtually no chance it will sting you. A mud dauber will not attack.

Researchers who have somehow been able to provoke and compare mud dauber stings to that of other wasps, bees and hornets, say the venom of the mud dauber produces discomfort that is on the low end of the pain scale.

I must say that “dirt dobbers” and I are not the greatest of friends. Virtually everything I own that is not closed up tightly inside is adorned with dried clumps of dirt that used to be active nests.

On the other hand, the daubers are welcome to all the spiders they want.

Steve Vantreese, a freelance outdoor writer, can be contacted at