Mud-nesting
Guides
Ageniella
mud-nesting spider wasps
Ageniella is a genus of small, slender spider wasps in the family Pompilidae, tribe Ageniellini. Members construct mud nests—typically trumpet- or thimble-shaped cells—each stocked with a single paralyzed spider and provisioned with one egg. The genus includes at least one documented cave-nesting species (Ageniella evansi) and species exhibiting ant-mimicry. Sexual dimorphism is pronounced: females are often reddish or orange-brown with banded wings, while males are black with reddish leg markings and a white abdominal tip.
Auplopus architectus
Auplopus architectus is a small to medium-sized spider wasp in the family Pompilidae. Females construct distinctive barrel-shaped mud nests, often inside pre-existing cavities such as rock crevices, wood holes, or abandoned nests of other wasps. The species hunts spiders, amputates their legs to facilitate transport, and provisions each mud cell with multiple paralyzed victims before laying a single egg. Populations occur in disjunct regions of North America including California, the northeastern United States, and Arkansas.
Euodynerus foraminatus
Potter wasp, Mason wasp
Euodynerus foraminatus is a solitary mason wasp in the family Vespidae, subfamily Eumeninae. Females construct multi-celled nests in pre-existing cavities such as holes in wood or abandoned bee burrows, provisioning each cell with paralyzed caterpillars as food for their larvae. The species is notable for having single-locus complementary sex determination, which typically produces sterile diploid males, yet field studies have documented surprisingly high rates of sibling mating in natural populations. It is widespread across North America and readily uses artificial nest structures such as bee blocks.
Maricopodynerus maricoporum
Maricopodynerus maricoporum is a species of potter wasp in the subfamily Eumeninae, first described by Viereck in 1908. The genus Maricopodynerus is a small group of solitary wasps endemic to arid regions of southwestern North America. As with other eumenine wasps, females construct mud nests provisioned with paralyzed caterpillars for their larvae. The species epithet 'maricoporum' refers to the Maricopa people or region in Arizona, indicating the type locality.
Masarinae
Pollen Wasps
Masarinae, commonly known as pollen wasps, is a subfamily of solitary wasps within Vespidae. Unlike their social and predatory relatives, pollen wasps provision their nests exclusively with pollen and nectar, resembling bees in their foraging behavior. The subfamily is small but globally distributed, with notable diversity in western North America, southern Africa, southern Europe, central Asia, and Australia. In North America, only the genus Pseudomasaris occurs, with 14 species. Many species exhibit strong flower associations, often oligolectic, specializing on particular plant genera such as Penstemon, Phacelia, and Eriodyction.
Stenarella
Stenarella is a genus of ichneumonid wasps in the subfamily Cryptinae, subtribe Osprynchotina. The genus is monophyletic and distributed across the Old World, with three major biogeographic clades corresponding to the Afrotropical, Palearctic, and Oriental–Australasian regions. Eighteen species are currently recognized, twelve described as new in a 2025 phylogenomic revision. Species are ectoparasitoids of aculeate Hymenoptera that construct nests using mud or earth.