Investigating physical and mechanical properties of nest soils used by mud dauber wasps from a geotechnical engineering perspective

Abstract

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.

New San Francisco Bay Area spittlebug of the genus Clastoptera Germar, 1839 (Hemiptera: Cercopoidea: Clastopteridae) makes unique mineral-crusted spittles

“…This distinguishes C. mineralis from every other spittlebug in the New World with known nymphal ecology. These encrustations, which linger after adult emergence, might be casually mistaken for amorphous mud wasp nests (see Park et al 2022 for illustrations). The origins of the mineral substances, however, are entirely different.…”

Morphometric and soil texture analysis of soil material from wasp nests Sceliphron destillatorium (Illiger, 1807) (Apoidea: Sphecidae)

“…Normally, a wasp lays an egg in a cell and usually attaches it to the first victim in the cell (Polidori et al, 2005). After the female has built the first cell and provided her offspring, she builds the next cell (Park et al, 2022).…”

“…After building several cells (the number varies), S. destillatorium covers the nest with an additional layer of soil material to protect the offspring from predators (e.g., parasitoid wasps, bee flies and birds) and changeable environmental conditions (e.g., extreme temperature, humidity and rainwater) (Park et al, 2022).…”

Charging Effect on Soil Particles in Scanning Electron Microscopy (SEM)

“…The study of surface microstructure of soil particles gives insights of the sedimentary history of the soil particles (Vos et al, 2014). The applications of SEM in soil mechanics are to study grain outline: roundness or angularity, transportation mode, distance and time travelled, and size (Park et al, 2022), fabric orientation (Song et al, 2022), forensic analysis of soil and sediment traces (Jafery et al, 2022), trace of heavy metals in soil (Burdalski et al, 2022), and morphological investigations up to a scales of micrometer to nanometer (Islam et al, 2022). The wide applications of SEM imaging in soil mechanics have attracted attention among researchers.…”