[PHOTOS TAKEN: MARCH 10TH, 2025 | Image IDs: Eleven photos of a pair of old organ pipe mud dauber nests that have been removed from their original surfaces, the first one shows the backs of both, each with a multitude of chambers; one on the right with sixteen or seventeen chambers and the other on the left with thirteen chambers. The pipe-like structures of each are individually shown from the front and the back in two pairs of photos, another three photos following each pair that show pieces of spiders in most, with a few containing spun silk from the former larval wasp residents making structures to pupate in /End IDs.]
A pair of old organ pipe mud dauber (Trypoxylon politum) nests I found on a metal barrel! Didn't initially intend to take them off, they just popped off of the surface with a slight touch, but it's a good opportunity to show you guys what these things look like from the other side!
This species is one of the many that are specialized to hunt spiders, provisioning their larvae with paralyzed spiders. You can see bits of leftover spiders in each chamber, which makes me wonder how much of it was eaten, assuming the nest was truly left behind already. What I am sure of, however, is; Despite the devastating precision and skill of these hymenopteran hunters when it comes to spiders, they are, like most parasitoid wasps, extremely difficult to provoke, so there's no need to be concerned about a sting around them!
You can also see that some of the chambers have silk spun inside of them—This is because, like many other holometabolous insects (i.e. insects that pupate into adulthood), hymenopterans are silk spinners, the cocoons that they pupate within being made of the material, much like the moth/butterfly chrysalises you may be aware of (yes, that does mean that ants, bees, and sawflies are silk spinners as larvae as well)! In line with that comparison, the adults of these and most wasp species cannot spin silk (apart from those in the genus Microstigmus)—Hence the nests that are built almost exclusively out of mud.
