Solitary-wasp
Guides
Solierella
Solierella is a genus of solitary digger wasps in the family Crabronidae, tribe Miscophini. Species nest in soil and provision their larvae with paralyzed spiders. The genus has been recorded from North America and India. Males patrol nesting areas, and nests are subject to parasitism by chrysidid wasps.
Sphaeropthalma amphion
Sphaeropthalma amphion is a species of velvet ant in the family Mutillidae, first described by Fox in 1899. Like other members of this genus, it is a parasitoid wasp with wingless females and winged males. The species is part of a diverse group of solitary wasps known for their aposematic coloration and painful stings. Very little specific information is available for this particular species.
Sphaeropthalma auripilis
Sphaeropthalma auripilis is a species of velvet ant in the family Mutillidae, first described by Blake in 1871. Velvet ants are solitary wasps in which females are wingless and often brightly colored with aposematic coloration warning of their painful sting. The genus Sphaeropthalma is one of the larger genera within Mutillidae in North America. This species is part of a diverse group of parasitoid wasps that primarily attack other solitary wasps and bees.
Sphaeropthalma blakeii
Sphaeropthalma blakeii is a species of velvet ant in the family Mutillidae, first described by Fox in 1893. The genus Sphaeropthalma is among the most diverse mutillid genera in North America. Like all velvet ants, females are wingless and wasp-like in appearance, while males possess wings. The species is poorly documented in the literature, with limited information available beyond taxonomic records.
Sphaeropthalma difficilis
Sphaeropthalma difficilis is a species of velvet ant (family Mutillidae), a group of solitary wasps known for their aposematic coloration and powerful stings. Females are wingless and resemble ants, while males possess wings. The species was described by Baker in 1905. Like other mutillids, it is presumed to be a parasitoid of other insects, though specific host records for this species are not well documented.
Sphaeropthalma imperialis
Sphaeropthalma imperialis is a species of velvet ant (family Mutillidae), a group of solitary wasps known for their aposematic coloration and potent sting. Females are wingless and resemble large, hairy ants, while males possess wings. The species was described by Blake in 1871. Like other mutillids, this species exhibits sexual dimorphism and is parasitoid in its life history. The genus Sphaeropthalma is diverse and primarily distributed in the Americas.
Sphaeropthalma marpesia
Sphaeropthalma marpesia is a species of velvet ant in the family Mutillidae, described by Blake in 1879. The species is distributed across the western and southwestern United States and Mexico. Velvet ants in this genus are solitary wasps with wingless females and winged males. The specific epithet 'marpesia' references the Amazon queen Marpesia, a namesake shared with the daggerwing butterflies of genus Marpesia.
Sphaeropthalma pensylvanica
velvet ant
Sphaeropthalma pensylvanica is a velvet ant (family Mutillidae), a group of solitary wasps known for their striking aposematic coloration and painful sting. The species exhibits notable sexual dimorphism: females are wingless and resemble ants, while males possess wings. It has been documented as a parasitoid of mud dauber wasps, particularly developing within cocoons of the organ pipe mud dauber (Trypoxylon politum). Research has revealed unusual reproductive characteristics including facultative size-dependent sex allocation, where larger females produce proportionally more female offspring. The species is also notable for phoretic copulation, a mating behavior in which the male transports the female by flight or foot from the initial contact site before mating occurs.
Sphaeropthalma pensylvanica pensylvanica
velvet ant
A velvet ant subspecies in the family Mutillidae, notable for being the first record of phoretic copulation in the subfamily Sphaeropthalminae. Males transport females by flight and/or foot from the initial contact site before mating occurs. The species is a solitary parasitoid with unusual sex allocation patterns and has been reared from cocoons of the organ pipe mud dauber (Trypoxylon politum).
Sphaeropthalma pinalea
velvet ant
Sphaeropthalma pinalea is a species of velvet ant in the family Mutillidae, described by Schuster in 1958. Like other members of this genus, the females are wingless and ant-like in appearance, while males possess wings. The species is part of a diverse North American velvet ant fauna, with the genus Sphaeropthalma containing numerous species primarily distributed in western and southwestern United States.
Sphaeropthalma pluto
Sphaeropthalma pluto is a species of velvet ant in the family Mutillidae, first described by Fox in 1899. Velvet ants are actually solitary wasps, with wingless females that resemble ants in appearance. The species is part of a diverse genus containing multiple described species, several of which have been documented in museum collections. As with other mutillids, females are likely parasitoids of other insects, though specific host records for this species remain limited.
Sphaeropthalminae
Sphaeropthalminae is a species-rich subfamily of velvet ants (Mutillidae), a group of solitary wasps in which females are wingless and males are winged. Phoretic copulation—where a male physically transports a female by flight and/or foot from their initial site of contact before mating—has been documented in at least one member, Sphaeropthalma pensylvanica, representing the first record of this behavior for the subfamily. The subfamily exhibits sexual dimorphism, with flightless females and winged males.
Sphecinae
digger wasps, thread-waisted wasps, grass-carrying wasps
Sphecinae is a subfamily of digger wasps (family Sphecidae) characterized by thread-waisted bodies and solitary nesting behavior. Members construct nests in soil, plant stems, or pre-existing cavities, provisioning cells with paralyzed prey for their larvae. The subfamily includes notable genera such as Sphex, Isodontia, and Podalonia, with diverse nesting strategies ranging from burrowing to grass-carrying.
Sphecius
Cicada-killer Wasps, Cicada Killers
Sphecius is a genus of large, solitary, ground-dwelling predatory wasps commonly known as cicada-killer wasps. The genus comprises 21 recognized species worldwide, with highest diversity in the region between North Africa and Central Asia. Females hunt adult cicadas, sting them into paralysis, and provision underground nests with these prey items for their larval offspring. The genus is notable for pronounced sexual size dimorphism, with females approximately twice the size of males, and for complex male territorial behavior. Four species occur in the Americas: S. speciosus (eastern), S. grandis (western), S. convallis (Pacific), and S. hogardii (Caribbean).
Sphecius convallis
Pacific cicada killer, Pacific cicada-killer wasp
Sphecius convallis, the Pacific cicada killer, is a large solitary wasp in the family Crabronidae. Females hunt cicadas, paralyze them with venom, and transport them to underground burrows as food for their larvae. The species occurs in arid and semi-arid regions west of the 100th meridian in North America, with populations studied intensively in Arizona mine tailings. Research has documented complex behavioral ecology including kleptoparasitism, thermal regulation strategies, and sex-specific provisioning behaviors.
Sphecius grandis
Western Cicada Killer, Western Cicada-killer Wasp
Sphecius grandis is a large, solitary wasp endemic to western North America, ranging from Central America through Mexico to the Western United States. Females construct burrows in sandy, well-drained soils, often forming nest aggregations with hundreds of individual nests. They provision underground cells with paralyzed cicadas (primarily Tibicen duryi, T. dealbata, and T. parallela) as food for their larvae. The species exhibits pronounced sexual dimorphism: females are larger (forewing length 2.5–3 cm, mass ~256 mg) and live approximately one year, while smaller males (~95 mg) emerge earlier, live only a few days, and engage in aggressive territorial competition for mating access. Activity is concentrated in July and early August, synchronized with cicada emergence. Despite their large size and formidable appearance, they are not habitually aggressive toward humans.
Sphecius hogardii
Caribbean cicada killer, Caribbean Cicada-killer Wasp
Sphecius hogardii, commonly known as the Caribbean cicada killer, is a large solitary wasp in the family Crabronidae. It is one of four North American species in the genus Sphecius, all of which specialize in hunting cicadas to provision underground nests. The species is found in the Caribbean region and extends into southern Florida. Like other cicada killers, females paralyze cicadas with venom and transport them to burrow cells as food for their developing larvae.
Sphecius speciosus
Eastern cicada-killer wasp, cicada killer, cicada hawk
Sphecius speciosus is a large, solitary digger wasp and one of the largest wasps in eastern North America. Females hunt cicadas, paralyzing them with venom to provision underground nest cells for their larvae. Despite their formidable size and appearance, they pose minimal threat to humans—females rarely sting unless roughly handled, and males lack stingers entirely. The species exhibits pronounced sexual dimorphism, with females substantially larger to accommodate egg-laying and prey transport duties.
Sphex ashmeadi
thread-waisted wasp
Sphex ashmeadi is a species of thread-waisted wasp in the family Sphecidae. It has been observed in New Mexico, USA, where it visits milkweed flowers. The species is part of the diverse Sphex genus, which includes solitary wasps that excavate burrows and provision them with paralyzed prey for their larvae.
Sphex flavovestitus
Sphex flavovestitus is a species of thread-waisted digger wasp in the family Sphecidae, first described by Frederick Smith in 1856. The species is distributed across the Americas, with records from North America, Middle America, and South America. Two subspecies are recognized: the nominate Sphex flavovestitus flavovestitus and Sphex flavovestitus saussurei. Like other members of the genus Sphex, it is a solitary wasp that constructs subterranean nests provisioned with paralyzed prey for its larvae.
Sphex habenus
Golden-reined Digger Wasp
Sphex habenus is a solitary thread-waisted wasp in the family Sphecidae. Like other members of the genus Sphex, females construct individual subterranean nests provisioned with paralyzed prey for their larvae. The species is distributed across North and Middle America.
Sphex ichneumoneus
Great Golden Digger Wasp, Great Golden Sand Digger
Sphex ichneumoneus is a large, conspicuous solitary wasp distributed across the Western Hemisphere from Canada to South America. Females excavate vertical burrows in sandy soils, provisioning individual cells with paralyzed katydids and related Orthoptera as food for their larvae. The species exhibits a distinctive fixed action pattern during prey retrieval, repeatedly inspecting the burrow entrance before dragging prey inside by the antennae—a behavior famously cited in discussions of genetic determinism. Adults forage for nectar at flowers and are frequently observed on blooms of rabbitbrush, prairie clover, and grape.
Sphex jamaicensis
Jamaican Digger Wasp
Sphex jamaicensis is a solitary thread-waisted wasp in the family Sphecidae. It is known from Florida, Cuba, the Bahamas, and Jamaica. Like other members of the genus Sphex, females are fossorial diggers that construct burrows in soil. The species was originally described by Drury in 1773 in the genus Vespa, creating a complex nomenclatural history involving a secondary homonym with a later Fabricius 1775 description.
Sphex lucae
katydid hunter
Sphex lucae is a solitary thread-waisted wasp in the family Sphecidae, native to western North America. This species exhibits pronounced sexual dimorphism: females have a black body with red abdomen and yellowish to violaceous wings, while males are entirely black with violaceous wings. Females are fossorial hunters that excavate subterranean burrows and provision them with paralyzed katydids as food for their larvae. Males form communal sleeping clusters in sheltered locations. The species is the sole North American representative of the subgenus Fernaldina, named for entomologist Henry Torsey Fernald.
Sphex nudus
Katydid Wasp
Sphex nudus, commonly known as the katydid wasp, is a solitary digger wasp in the family Sphecidae. Females construct subterranean nests in soil or dirt substrates, including the floors of old barns. The species is notable for its specialized hunting behavior, targeting leaf-rolling crickets as prey for its larvae. It occurs across the eastern United States.
Sphex pensylvanicus
Great Black Wasp, Great Black Digger Wasp
Sphex pensylvanicus is a large, solitary digger wasp native to North America. Females construct underground burrows and provision them with paralyzed orthopteran prey, primarily katydids, for their larvae. Adults feed on nectar from diverse flowering plants and serve as pollinators. The species exhibits protandry, with males emerging before females in the breeding season. Despite their formidable size and appearance, they are not aggressive toward humans and sting only when handled.
Sphex tepanecus
Sphex tepanecus is a species of thread-waisted digger wasp in the family Sphecidae. It is a large solitary wasp known from the western United States, with records from Arizona, Colorado, and potentially Idaho. Like other members of the genus Sphex, it constructs subterranean nests and provisions them with paralyzed prey for its larvae. The species was first described by de Saussure in 1867.
Spilomena
Spilomena is a genus of solitary wasps in the family Crabronidae (subfamily Pemphredonidae). The genus contains approximately 86 species distributed worldwide, with highest diversity in the Palearctic realm. Species are known as aphid wasps or thrips-hunting wasps, with documented prey including Psyllidae, Eulophidae, and Thysanoptera. One Australian species, S. subterranea, is known to nest communally in sandy soil.
Spilomena hainesi
Spilomena hainesi is a solitary wasp species in the subfamily Pemphredoninae, described in 1995 by N. Smith. Like other members of its genus, it is an aphid wasp that provisions nests with aphids as food for its larvae. The species is known from North America.
Spilomena occidentalis
aphid wasp
Spilomena occidentalis is a species of solitary aphid wasp in the family Crabronidae (subfamily Pemphredoninae). It was described by R. Bohart in 1995. The species is known from North America, with records from Canada including Alberta. Like other members of its genus, it is a predator of aphids, provisioning its nests with paralyzed prey for its larvae.
Steniolia elegans
sand wasp
Steniolia elegans is a solitary sand wasp in the family Crabronidae. Females dig burrows in dry, powdery soil and provision them with paralyzed flies for their single offspring. The species exhibits progressive provisioning, with females repeatedly hunting and delivering prey throughout larval development. Both sexes form dense, spherical sleeping clusters at night where mating occurs.
Steniolia eremica
Steniolia eremica is a species of sand wasp in the family Crabronidae, described by James E. Gillaspy in 1964. It is one of approximately fifteen species in the genus Steniolia, all of which are restricted to western North America. Males are larger than females and have been observed visiting thistle flowers and other nectar sources. The species is considered less abundant than congeners that share its range.
Steniolia obliqua
Steniolia obliqua is a species of sand wasp in the family Crabronidae, originally described as Monedula obliqua by Cresson in 1865. It belongs to a genus of fourteen North American species, all with western distributions. Like other Steniolia species, it is a solitary wasp that hunts flies to provision underground nests for its larvae. The species has been recorded in British Columbia, Canada.
Steniolia scolopacea
Steniolia scolopacea is a sand wasp in the family Crabronidae, distributed across Central America and North America. It belongs to a genus of fourteen North American species, all western in distribution. Two subspecies are recognized: S. s. albicantia and the nominate S. s. scolopacea. Like other Steniolia species, it is a solitary wasp that hunts flies as prey for its larvae.
Stenodynerus
Stenodynerus is a large genus of potter wasps (subfamily Eumeninae) distributed across the Nearctic, Palearctic, Oriental, and Neotropical regions. Females are known to provision nests with paralyzed caterpillars as food for their larvae. The genus is morphologically close to Parancistrocerus, Hypancistrocerus, and Eustenancistrocerus, with which it shares diagnostic features including medial pits on the anterior pronotum and expanded tegulae. Most species lack a transverse carina on the first metasomal tergum.
Stenodynerus anormis
Mason wasp
Stenodynerus anormis is a solitary mason wasp in the subfamily Eumeninae. The species is difficult to distinguish from the related genus Parancistrocerus based on live specimens or photographs; microscopic examination of actual specimens is often required for positive identification. Females are known to provision nest cavities with paralyzed caterpillars as food for their larval offspring. The species has been documented utilizing artificial nesting structures such as bee blocks.
Stenodynerus blandoides
Stenodynerus blandoides is a species of solitary mason wasp in the subfamily Eumeninae, described by Bohart in 1943. It is a small, cavity-nesting wasp that provision nests with paralyzed caterpillars for its larval offspring. The species is difficult to distinguish from closely related genera such as Parancistrocerus based on live specimens alone. Like other eumenine wasps, it utilizes pre-existing tunnels in wood or hollow stems for nesting.
Stenodynerus blandus
Stenodynerus blandus is a species of mason wasp in the family Vespidae, subfamily Eumeninae. It is a small, solitary, cavity-nesting wasp that provisionally places paralyzed caterpillars in pre-existing cavities for its larval offspring. The species is difficult to distinguish from the closely related genus Parancistrocerus based on external morphology alone, often requiring microscopic examination for definitive identification. It has been documented utilizing artificial nesting structures such as bee blocks.
Stenodynerus blepharus
Stenodynerus blepharus is a species of solitary mason wasp in the subfamily Eumeninae, described by Bohart in 1953. The species is currently treated as a synonym of Rhynchalastor blepharus in some taxonomic databases, reflecting ongoing taxonomic revision in this group. As with other Stenodynerus species, it is presumed to be a cavity-nesting wasp that provisions its larvae with paralyzed caterpillars. Direct observations of this specific species in the field are sparse, with only two observations recorded in iNaturalist.
Stenodynerus fundatiformis
A small solitary mason wasp in the subfamily Eumeninae. The species is difficult to distinguish from related genera such as Parancistrocerus based on live specimens alone; microscopic examination is typically required for definitive identification. Females are known to provision nests with paralyzed caterpillars for their larval offspring. Males have been observed foraging on flowers, with the last antennal segment characteristically folded against the adjacent segment.
Stenodynerus fundatiformis fundatiformis
Stenodynerus fundatiformis fundatiformis is a subspecies of mason wasp in the subfamily Eumeninae. It is a solitary, cavity-nesting wasp that provisions its nests with paralyzed caterpillars as food for its larval offspring. The subspecies is difficult to distinguish from similar genera such as Parancistrocerus based on live specimens alone, often requiring microscopic examination for definitive identification.
Stenodynerus fundatiformis gonosceles
Stenodynerus fundatiformis gonosceles is a subspecies of mason wasp in the subfamily Eumeninae. The genus Stenodynerus contains solitary, cavity-nesting wasps provisioned with paralyzed caterpillars. This subspecies is poorly documented in available sources, with only one observation recorded on iNaturalist. Males of the genus have a distinctive antennal modification: the last antennal segment is folded like a finger against the adjacent segment.
Stenodynerus histrionalis
Stenodynerus histrionalis is a solitary mason wasp in the subfamily Eumeninae, native to western North America. The species is difficult to distinguish from similar genera such as Parancistrocerus based on external morphology alone, often requiring microscopic examination of specimens. Females are known to provision nests with paralyzed caterpillars as food for their larvae. Males possess a distinctive antennal modification: the last segment is folded like a finger against the adjacent segment.
Stenodynerus histrionalis paenevagus
Stenodynerus histrionalis paenevagus is a subspecies of solitary mason wasp in the family Vespidae, subfamily Eumeninae. Like other Stenodynerus species, it is a cavity-nesting wasp that provisions its nests with paralyzed caterpillars as food for its larval offspring. The subspecies is difficult to distinguish from related taxa based on field observations alone, and microscopic examination is typically required for definitive identification. It has been documented in Colorado and California, where it utilizes pre-existing cavities in wood or other substrates for nesting.
Stenodynerus krombeini
Stenodynerus krombeini is a solitary mason wasp in the subfamily Eumeninae. It is a small, cavity-nesting species that provisions its nests with paralyzed caterpillars as food for its larvae. The species is difficult to distinguish from the closely related genus Parancistrocerus based on images of live specimens; microscopic examination is typically required for definitive identification. Males have a distinctive antennal structure with the last segment folded against the adjacent segment.
Stenodynerus lineatifrons
Stenodynerus lineatifrons is a species of solitary mason wasp in the subfamily Eumeninae. It is a cavity-nesting wasp that provisions its nests with paralyzed caterpillars for its larval offspring. The species was described by Bohart in 1948 and is currently considered a synonym of Rhynchalastor lineatifrons in some taxonomic databases, though it remains listed under Stenodynerus in others. Like other members of its genus, it is difficult to distinguish from the related genus Parancistrocerus based on images of live specimens.
Stenodynerus lucidus
Stenodynerus lucidus is a small solitary mason wasp in the subfamily Eumeninae. The species was described by Rohwer in 1917 and is currently considered a synonym of Rhynchalastor lucidus by some taxonomic authorities, though it remains listed under Stenodynerus in other sources. Like other eumenine wasps, it nests in pre-existing cavities and provisions its cells with paralyzed caterpillars as food for its larvae.
Stenodynerus microstictus
Stenodynerus microstictus is a solitary mason wasp in the subfamily Eumeninae. The species is difficult to distinguish from closely related genera such as Parancistrocerus based on external appearance alone. Females are known to provision nests with paralyzed caterpillars as food for their larvae. The species has been documented in western North America, including Colorado and California.
Stenodynerus ochrogonius
A solitary mason wasp in the subfamily Eumeninae, originally described by Bohart in 1944. Currently treated as a synonym of Rhynchalastor ochrogonius in some taxonomic databases, though iNaturalist and other sources maintain it under Stenodynerus. Like other eumenine wasps, females are predatory on caterpillars, which they paralyze and provision in nest cells for their larval offspring. Males have a distinctive antennal modification with the last segment folded like a finger against the adjacent segment. The species has been documented in Colorado and California.
Stenodynerus oculeus
Stenodynerus oculeus is a solitary mason wasp in the subfamily Eumeninae. It is a small, cavity-nesting species that provisions its nests with paralyzed caterpillars as food for its larvae. The species is difficult to distinguish from closely related genera such as Parancistrocerus without microscopic examination. Males have been observed foraging on flowers, with the last antennal segment modified into a finger-like structure folded against the adjacent segment.