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Pipe Organ Mud Dauber Wasp Nest

Trypoxylon politum


This has to be the largest Pipe Organ Mud Dauber Wasp Nest I've ever come across - about a meter wide and just under a meter in height. How they are created is explained in the "Notes".


Spotted under the hwy 67 or Valley street bridge where it crosses the Caddo river at Caddo Valley, Arkansas.


Mud-dauber wasps nest on cliffs, walls and bridges with easy access to mud. They make their nests on smooth, vertical surfaces sheltered from sunlight and rain. To make one, the female wasp shapes mud into a pipe and partitions it into a few "brood chambers". There she will lay eggs and stockpile several small spiders or a few large ones for her young to eat. Before collecting mud, a female checks its consistency with her mouth; she tests quite a few sources before settling on one. Once she is satisfied, she lunges with her jaws spread out and scoops some mud. Then passing it on to her front legs, she again lunges and scoops some more, and finally flies away with the load. With every load of mud brought thereafter, she makes a strip starting in the middle, working it downwards to meet the surface. A strip on one side is alternated with that on the other. The resulting nest has an inverted V-shaped striped appearance on the outside; on the inside it is made smooth. A male guards the nest while the female builds it, and when she is away collecting spider-food for their unborn children.(

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Brian38 a year ago

Thank you so much Leuba. I was surprised when I found it. The nest was on the easterly side of the bridge giving the wasp the fastest access to the the mud at the rivers edge. So much intelligence with wasp - They just amaze me!

Leuba Ridgway
Leuba Ridgway a year ago

Amazing shape and size. What a lot of hard work ! Lovely spotting Brain38.

Brian38 a year ago

Thank you SukanyaDatta.

SukanyaDatta a year ago

Good luck Brian...I see these from time to time but the clusters are limited to 3-4 only. This one is huge! Apparently the wasp buzzes to liquefy the mud...thixotropy!

Brian38 a year ago

Thank you Maria.

Maria dB
Maria dB a year ago

That is a great description of the construction, Brian38. I photographed some of these nests recently but had not read up on how they are made, so I learned something from your spotting!

Brian38 a year ago

Thank you Ashley for the nomination.

AshleyT a year ago

Your spotting has been nominated for the Spotting of the Week. The winner will be chosen by the Project Noah Rangers based on a combination of factors including: uniqueness of the shot, status of the organism (for example, rare or endangered), quality of the information provided in the habitat and description sections. There is a subjective element, of course; the spotting with the highest number of Ranger votes is chosen. Congratulations on being nominated!

Spotted by

Arkansas, USA

Lat: 34.18, Long: -93.07

Spotted on Sep 1, 2018
Submitted on Sep 16, 2018

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