Mud dauber wasps

The quality of nest soils has significant effects on reproductive success in mud dauber species. This study investigated the physical and mechanical properties of the nest soils used by mud daubers from a geotechnical engineering perspective. One hundred thirty-one nests of black and yellow mud daubers were collected from five locations in the south of Louisiana. Moisture and organic contents, densities, void ratios, plasticity, grain size distributions, soil classifications, and penetration resistances of the nest soils were measured. Also, the performance of mud daubers’ nest-compaction method (i.e., repetitive tapping produced by the front legs and mandibles) was evaluated by comparing the densities and penetration resistances between mud dauber nests and Proctor compacted nest soil samples. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction were used to measure the morphology, elemental composition, and mineralogy of the nest soils. Mud dauber nests were made of hard and very stiff well-graded silty soils. The high strengths and high densities of mud dauber nests were attributed to repetitive tapping (similar to vibratory compaction in geotechnical engineering) used by mud daubers for nest construction, high capillary cohesion in the nest soils, well-graded soil grain size distribution, and clay minerals serving as cementing agents in the nest soils.

Publications

Figure 1. Nest construction process of black and yellow mud dauber: (a) a mud dauber collects and forms soil into a soil ball and (b) plasters the soil ball on the nest; (c) nest cells are provisioned with spiders; and (d) a mud dauber closes the opening of the cell using collected soil.

(a): photo courtesy of an author named Hglu1 via https://commons.wikimedia.org/wiki/File:20100710.MudDauber-SceliphronCaementarium.‌Hannibal.jpg. The photo is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported license. The license terms can be found on the following link: https://creativecommons.org/‌licenses/by-sa/3.0/.

(b), (c), and (d): photo courtesy of authors named mnwild, Patrick Coin, and Ricardo Arredondo T. via https://www.inaturalist.org/observations/39302921, https://www.inaturalist.org/observations/8419859, and https://www.inaturalist.org/observations/10717949. These photos are licensed under a Creative Commons Attribution-NonCommercial 4.0 International license. The license terms can be found on the following link: https://creativecommons.org/licenses/by-nc/4.0/.


Figure 2. (a) Standard and modified Proctor compaction curves compared to (b) the dry density distribution of the mud dauber nest samples.