September 07, 2021
I have noticed a long tube-like structure above the entrance where I work for several weeks. I was unsure of what this was as I had never seen one before. My curiosity finally got the best of me over the weekend, and I did a google search with my phone on the tube. I found it belonged to a type of mud dauber. The mud dauber nests that I am used to are a single cell, but this one was about seven inches long. I have never been fond of wasps as I have found they are aggressive when guarding their nests. When I was director of the rural camp, I was constantly trying to get rid of wasp nests and the angry wasps that guarded them. Luckily there are spray cans that shoot a spray twenty-seven feet to take out the wasp nests that seemed to accumulate under the eaves of our buildings.
When I went online, I found the Organ pipe mud dauber (Trypoxylon politum) is a predatory wasp in the family Crabronidae that ranges from Southeastern Canada to Eastern US. These are large wasps, ranging from 1.5 to 2 inches (3.9 to 5.1 cm) that are active from May to September. The female and male are similar in color, being a shiny black with pale yellow to white hind tarsomere. The Organ pipe mud dauber feeds on various species of the orb-weaver (Araneidae) spiders. The female dauber forms a long mud tube consisting of multiple cells, each fortified with a paralyzed spider. The female then lays an egg in each cell, and when the egg hatches the larvae feed on the spider. The larvae then pupate until they become adults. The female generally constructs 5 to 6 pipes in a cluster, either side-by-side or on top of each other. A newly hatched adult female will usually begin building her new nest within 48 hours of leaving her birth nest. Interestingly, our nest had only one pipe.
The Organ pipe mud dauber is said to be an exceedingly docile species of wasp. They also serve to keep down the spider populations that thrive in and around buildings. Stings to humans are only in self-defense, such as if a wasp is squeezed (whose bright idea found this out?). The tufted titmouse (Parus bicolor) is a known predator of the mud dauber and may feed on them more commonly than previously thought. The holes made by the titmouse are similar in shape and size to those made by a mud dauber leaving the nest after pupation. The mud tube I found was located near an abandoned paper wasp (vespid subfamily Polistinae) nest under the portico at the entrance of our building. A barn swallow nest is located against the light in the center of the portico. It made me wonder if the barn swallow that lives in the nest had feasted on both types of wasps before they could complete building their nests.
Thoughts: While I have never been too concerned about the mud dauber nests, I cannot say the same for the paper wasps. I once walked into a bathroom at the lake where I worked and was immediately stung five or six times by the wasps who had taken up residence there. Then it became my job to get them out, so it did not happen to other campers. I could have used one of the spray cans on that day. The single Organ pipe mud dauber tube reminded me of the interrelated cycle of life. The orb spiders create spiral webs to capture small flying insects. The mud dauber captures the spider and leaves it as food for its larva. The dauber is caught and eaten by the swallow. Usually, all three nests would be destroyed by the humans who live in the building. While the nests were created to continue the cycle of life, their destruction by humans occurs for aesthetics. The different nests serve as a reminder for me to respect the creatures who live around me. If I do not get stung. Follow the science. Change is coming and it starts with you.