Mud dauber
Mud dauber is a name commonly applied to a number of wasps from either the family Sphecidae or Crabronidae which build their nests from mud; this excludes members of the family Vespidae, which are instead referred to as "potter wasps". Mud daubers are variable in appearance. Most are long, slender wasps about in length. The name refers to the nests that are made by the female wasps, which consist of mud molded into place by the wasp's mandibles. Mud daubers are not normally aggressive, but can become belligerent when threatened. Stings are uncommon.
Nests
The organ pipe mud dauber, one of many mud daubers in the family Crabronidae, builds nests in the shape of a cylindrical tube resembling an organ pipe or pan flute. Common sites include vertical or horizontal faces of walls, cliffs, bridges, overhangs, shelter caves, or other structures.The nest of a black and yellow mud dauber species Sceliphron caementarium is a simple, one-, two-, or sometimes three-celled, cigar-shaped mass that is attached to crevices, cracks, and corners. Each cell contains one egg. Usually several cells are clumped together and covered in mud. The blue mud dauber species Chalybion californicum, another sphecid, builds mud nests, but occasionally refurbishes the abandoned nests of other species. Its larvae are fed spiders; adults consume nectar. The two species commonly occupy the same barns, porches, or other nest sites.
All mud daubers may occupy the same sites year after year, creating large numbers of nests in protected locations; such sites are often used as nest sites by other kinds of wasps and bees, as well as other types of insects.
One disadvantage to making nests is that most, if not all of the nest-maker’s offspring are concentrated in one place, making them highly vulnerable to predation. Once a predator finds a nest, it can plunder it cell by cell. A variety of parasitic wasps, ranging from extremely tiny chalcidoid wasps to larger, bright green chrysidid wasps, attack mud dauber nests. They pirate provisions and offspring as food for their own young.
Food
Like most other solitary wasps, mud daubers are parasitoids, but unlike the majority of parasitoids, they actively capture and paralyze the prey upon which they lay their eggs. The females build the nests, and hunt to provision them. Males of pipe-organ mud daubers have been observed bringing spiders to the nest, and nest-guarding, an extremely rare appearance of male parental care, otherwise virtually unknown among Hymenoptera.Black and yellow mud daubers primarily prey on relatively small, colorful spiders, such as crab spiders, orb weavers and some jumping spiders. They usually find them in and around vegetation. Blue mud daubers are the main predator of the black and brown widow spiders. The wasp often shakes the web pretending to be caught order to lure out the host spider.
Adults of both sexes frequently drink flower nectar, but they stock their nests with spiders, which serve as food for their offspring. Mud daubers prefer particular kinds and sizes of spiders for their larders. Instead of stocking a nest cell with one or two large spiders, mud daubers cram as many as two dozen small spiders into a nest cell.
To capture a spider, the wasp grabs it and stings it. The venom from the sting does not kill the spider, but paralyzes and preserves it so it can be transported and stored in a nest cell until consumed by the larva. A mud dauber usually lays its egg on the prey item and then seals it into the nest cell with a mud cap. It then builds another cell or nest. The young survive the winter inside the nest.