Mason-bee
Guides
Ashmeadiella bucconis denticulata
Western Big-Cheeked Angled-Mason
Ashmeadiella bucconis denticulata is a subspecies of mason bee in the family Megachilidae. It is one of several subspecies within the Ashmeadiella bucconis species complex. The subspecies was originally described by Cresson in 1878 under the genus Heriades. Very few observations exist in citizen science databases, suggesting it may be uncommon or underreported.
Ashmeadiella xenomastax
Square-jawed Angled-Mason
Ashmeadiella xenomastax is a species of mason bee in the family Megachilidae, first described by Michener in 1939. It is known from Central and North America. The common name "Square-jawed Angled-Mason" refers to distinctive morphological features of the species. Like other members of the genus Ashmeadiella, it is a solitary bee that constructs nests using collected materials.
Dianthidium simile
Northeastern Pebble Bee
Dianthidium simile is a solitary bee species in the family Megachilidae, commonly known as the Northeastern Pebble Bee. It belongs to a group of bees known as resin bees, mason bees, and leafcutter bees, reflecting the diverse nesting materials used by members of this family. The species is native to North America, with confirmed records from the northeastern United States including Vermont. Like other Dianthidium species, it constructs nests using plant resins and other materials, and is subject to parasitism by specialized wasps such as leucospids.
Hoplitis albifrons
White-fronted Small-Mason
Hoplitis albifrons is a solitary mason bee in the family Megachilidae, tribe Osmiini. It is native to North America, with documented records from the northeastern United States including Vermont. As a member of the osmiine bees, it likely constructs nests in pre-existing cavities and uses mud or other materials to partition brood cells, though specific natural history details for this species remain poorly documented in available sources.
Hoplitis albifrons argentifrons
Silver-fronted Small-Mason
Hoplitis albifrons argentifrons is a subspecies of mason bee in the family Megachilidae, native to North America. As a member of the osmiine bees, it is a solitary species that constructs nests in pre-existing cavities. The subspecies designation indicates geographic variation within the broader H. albifrons species complex. Like other Hoplitis species, it contributes to pollination services in its native range.
Hoplitis albifrons maura
Pacific Black Small-Mason
Hoplitis albifrons maura is a subspecies of mason bee in the family Megachilidae, native to western North America. It belongs to a group of solitary bees known for nesting in pre-existing cavities and constructing brood cells from collected materials. As a member of the osmiine bees, it contributes to pollination services in its native range. The subspecies designation indicates geographic variation within the broader H. albifrons species complex.
Hoplitis anthocopoides
Viper's Bugloss Small-Mason
Hoplitis anthocopoides is a solitary mason bee in the family Megachilidae. It is a specialist pollinator of Echium vulgare (viper's bugloss), using this plant for both pollen/nectar collection and leaf material for nest construction. Females construct nests in pre-existing cavities using cut leaf pieces, creating linear series of 6-10 cells. Males exhibit territorial behavior, defending flower patches to gain access to females. The species has a broad distribution across Africa, Europe, Northern Asia (excluding China), and North America.
Hoplitis biscutellae
Creosote Small-Mason
Hoplitis biscutellae is a solitary mason bee in the family Megachilidae, first described by Cockerell in 1897. It is distributed across Central America and North America. Like other members of the genus Hoplitis, it is a cavity-nesting bee that constructs nests using mud or plant materials. The common name "Creosote Small-Mason" suggests an association with creosote bush (Larrea tridentata), though specific host plant relationships remain poorly documented.
Hoplitis bullifacies
Hoplitis bullifacies is a species of solitary bee in the family Megachilidae, first described by Michener in 1947. It belongs to the diverse genus Hoplitis, which comprises numerous small to medium-sized mason bees native to the Northern Hemisphere. The species is recorded from North America, though specific details about its biology and ecology remain poorly documented in published literature.
Hoplitis bunocephala
Hoplitis bunocephala is a solitary bee species in the family Megachilidae, described by Michener in 1947. The species is native to North America and belongs to the diverse genus Hoplitis, which includes numerous mason bee species. Like other members of Megachilidae, females carry pollen on scopae located on the underside of the abdomen rather than on the hind legs.
Hoplitis elongaticeps
Hoplitis elongaticeps is a solitary bee species in the family Megachilidae, first described by Michener in 1947. It belongs to the diverse genus Hoplitis, which comprises numerous mason bee species across the Northern Hemisphere. The species is known to occur in North America, though specific details about its biology and ecology remain limited in available sources.
Hoplitis fulgida
Green Small-Mason
Hoplitis fulgida is a solitary bee species in the family Megachilidae, commonly known as the Green Small-Mason. It is native to North America and belongs to the diverse genus Hoplitis, which includes numerous mason bee species. The species was first described by Cresson in 1864. Like other members of its genus, it is presumed to nest in pre-existing cavities and construct cells using collected materials.
Hoplitis fulgida fulgida
Hoplitis fulgida fulgida is a subspecies of mason bee in the family Megachilidae, first described by Cresson in 1864. As a member of the genus Hoplitis, it belongs to a group of solitary bees that construct nests using collected materials. The subspecies is part of the North American fauna of Osmia bees, though specific ecological details for this subspecies remain poorly documented in available literature.
Hoplitis fulgida platyura
Pacific Green Small-Mason
Hoplitis fulgida platyura is a subspecies of mason bee in the family Megachilidae. It is native to western North America, where it occurs from British Columbia to California. The subspecies is distinguished from the nominate form by structural differences in the male antennae and subtle coloration differences. Like other members of the genus Hoplitis, females construct nests in pre-existing cavities and line brood cells with collected materials.
Hoplitis howardi
Hoplitis howardi is a solitary bee species in the family Megachilidae, tribe Osmiini. First described by Cockerell in 1910, this species belongs to a large genus of mason bees that nest in pre-existing cavities. The genus Hoplitis is characterized by females that construct nest cells using collected materials such as leaf pieces, mud, or resin. H. howardi occurs in North America and Middle America, though specific ecological details remain poorly documented in published literature.
Hoplitis hypocrita
Mimic Small-Mason
Hoplitis hypocrita is a solitary bee species in the family Megachilidae, commonly known as the Mimic Small-Mason. It belongs to the tribe Osmiini, which includes many mason bee species that nest in pre-existing cavities. The species was originally described by Cockerell in 1906 as Osmia hypocrita before being transferred to the genus Hoplitis. It is native to North America.
Hoplitis producta
Produced Small-Mason
Hoplitis producta is a solitary bee species in the family Megachilidae, commonly known as the Produced Small-Mason. It is native to North America east of the Rocky Mountains and is considered common and widely distributed in this range. The species is notable for its nesting biology, having been documented using pith-filled plant stems for nest construction.
Hoplitis spoliata
Dilated-horned Small-Mason
Hoplitis spoliata is a solitary bee species in the family Megachilidae, commonly known as the Dilated-horned Small-Mason. It is a member of the diverse osmiine bee tribe, which includes many species that nest in pre-existing cavities and use various materials to construct brood cells. The species was first described by Provancher in 1888 and is native to North America, with documented occurrences in the northeastern United States including Vermont.
Hoplitis truncata
Truncate Small-Mason
Hoplitis truncata is a solitary bee species in the family Megachilidae, commonly known as the Truncate Small-Mason. It is part of the diverse osmiine bee group, which includes many species that nest in pre-existing cavities and use various materials to construct their nests. The species has been recorded in North America and parts of Southern Asia, though detailed biological information remains limited.
Lithurgopsis littoralis
Lithurgopsis littoralis is a species of bee in the family Megachilidae, described by Cockerell in 1917. It belongs to the subfamily Lithurginae, a group of bees commonly known as mason bees or resin bees. The species is recorded from Middle America and North America.
Megachile campanulae
Bellflower Resin Bee
Megachile campanulae, commonly known as the bellflower resin bee, is a solitary mason bee native to eastern North America. Described in 1903, this species belongs to the subgenus Chelostomoides, distinguishing it from leafcutting relatives by its use of plant resins, mud, and pebbles rather than cut leaves for nest construction. In 2013, researchers documented this species as one of the first insects known to incorporate synthetic materials, including polyurethane-based sealants, into nest construction. The species is an important pollinator of native plants and is nonaggressive toward humans.
Osmia
Mason Bees
Osmia is a large genus of solitary bees in the family Megachilidae, commonly known as mason bees. The genus includes approximately 500 species worldwide, with many species native to North America. Mason bees are named for their use of mud or other masonry materials to construct and seal nest cells. They are important pollinators of agricultural crops and native plants, and several species are managed commercially for orchard pollination. Unlike honey bees, mason bees are solitary, do not produce honey, and rarely sting.
Osmia aglaia
Oregon berry bee
Osmia aglaia is a solitary mason bee native to the western United States. It is commonly known as the Oregon berry bee due to its specialized role as a pollinator of brambles, particularly raspberries and blackberries. The species exhibits metallic coloration and nests in pre-existing wood tunnels. Adults are active in late spring, coinciding with Rubus bloom periods.
Osmia bucephala
bufflehead mason bee
Osmia bucephala, commonly known as the bufflehead mason bee, is a solitary bee species in the family Megachilidae native to North America. As a mason bee, it nests in pre-existing tubular cavities and uses mud to construct and seal brood cells. The species is part of the diverse Osmia genus, which includes many ecologically important pollinators. Limited specific ecological data is available for this species compared to better-studied congeners such as O. lignaria.
Osmia calaminthae
blue calamintha bee
Osmia calaminthae is a rare mason bee endemic to a restricted area of Florida scrub habitat. The species was described in 2011 and is known from only eleven sites concentrated in the southern Lake Wales Ridge and Ocala National Forest. It exhibits striking blue coloration and shows extreme host specialization, depending primarily on two mint-family plants for pollen. The species is considered Critically Imperiled due to its extremely limited range, specific habitat requirements, and ongoing threats from development and pesticide exposure. It was rediscovered in March 2020 after concerns about its continued existence.
Osmia chalybea
Osmia chalybea is a solitary mason bee (Megachilidae) native to North America. It nests in pre-existing cavities and has been studied as a potential pollinator for orchard crops, particularly blueberries. The species serves as a host for the cleptoparasitic bee Stelis ater. It is one of several Osmia species evaluated for commercial management in agricultural pollination systems.
Osmia clarescens
Osmia clarescens is a solitary mason bee in the family Megachilidae, described by Theodore Dru Alison Cockerell in 1911. The species occurs in Central America and North America. Like other members of the genus Osmia, it is a cavity-nesting bee that constructs nests in hollow stems or pre-existing holes, sealing brood chambers with mud. Specific ecological details and distinguishing characteristics remain poorly documented in the scientific literature.
Osmia coloradensis
Colorado Mason, Colorado osmia
Osmia coloradensis is a solitary mason bee in the family Megachilidae, native to western North America. Like other Osmia species, it nests in pre-existing cavities such as hollow plant stems or holes in wood, sealing nest chambers with mud. The species is recognized as a native pollinator with documented observations across multiple western U.S. states and parts of Central America. It belongs to a genus of bees increasingly valued for orchard pollination services, though specific management practices for this species are less developed than for commercially used relatives.
Osmia cornifrons
Horn-faced Mason Bee, Horned-face Bee
Osmia cornifrons is a solitary mason bee native to Northern Asia, widely managed as an agricultural pollinator. The species was first introduced to Japan in the 1940s for apple pollination and subsequently to the northeastern United States in 1977. It is recognized by distinctive horn-like projections on the lower face of females. The bee exhibits protandry, with males emerging 2–3 days before females. It has been documented as established in Canada since at least 2017. Populations remain stable and have not shown rapid expansion compared to the accidentally introduced congener O. taurus.
Osmia dakotensis
Osmia dakotensis is a solitary bee species in the family Megachilidae, described by Michener in 1937. It is native to North America. As a mason bee, it likely nests in pre-existing cavities and uses mud to construct brood cells. Beyond its taxonomic placement and geographic distribution, specific biological details remain poorly documented in available literature.
Osmia distincta
Beardtongue scraper bee
Osmia distincta is a solitary mason bee in the family Megachilidae, native to North America. It is commonly known as the beardtongue scraper bee, reflecting its association with Penstemon (beardtongue) plants. The species was described by Cresson in 1864 and has been documented in the northeastern United States, particularly Vermont. As a member of the genus Osmia, it nests in pre-existing cavities and provisions brood cells with pollen.
Osmia foxi
Osmia foxi is a species of mason bee in the family Megachilidae, subgenus Melanosmia. It was long considered enigmatic, known only from the male holotype until its redescription in 2011, which included the first description of the female. The species is restricted to the southwestern United States and northwestern Mexico, where it occurs in montane pine-oak forest habitats. It exhibits the metallic coloration typical of many Osmia species.
Osmia gaudiosa
Osmia georgica
Georgia Mason Bee
Osmia georgica is a solitary bee species in the family Megachilidae, commonly known as the Georgia Mason Bee. It is found across North America and Central America. As a member of the genus Osmia, it is a mason bee that constructs nests using mud or other materials. The species was described by Ezra Townsend Cresson in 1878.
Osmia glauca
Osmia glauca is a species of mason bee in the family Megachilidae, originally described as Heriades glaucum by Fowler in 1899. It is native to North America and belongs to a genus of solitary bees known for nesting in pre-existing cavities and sealing brood cells with mud. Like other Osmia species, it is likely a pollinator of flowering plants, though specific ecological details remain poorly documented.
Osmia integra
Osmia integra is a solitary mason bee species in the family Megachilidae, native to North America. It is distinguished by its nesting behavior in sand dune habitats, where it constructs shallow nests. The species was described by Cresson in 1878 and includes two recognized subspecies: O. i. integra and O. i. nigrigena. Like other Osmia species, it is a native pollinator, though specific ecological details remain understudied.
Osmia lignaria
blue orchard bee, orchard mason bee, BOB
A solitary megachilid bee native to North America, widely managed for pollination of early spring fruit crops including almonds, apples, and cherries. Distinguished by metallic blue coloration, smaller size than honey bees, and unique mud-nesting behavior. Divided into two subspecies by the Rocky Mountains: O. l. propinqua (west) and O. l. lignaria (east).
Osmia lignaria lignaria
Eastern Blue Orchard Bee
Osmia lignaria lignaria is the eastern subspecies of the blue orchard bee, a solitary mason bee native to North America. It is a managed pollinator prized for its efficiency in pollinating early spring-blooming fruit trees including almonds, apples, pears, and cherries. The bee nests in pre-existing cavities such as hollow stems and beetle holes, sealing nest entrances with mud. It has experienced population declines in the eastern United States, with research ongoing into competition with non-native Osmia species and vulnerability to pesticides and parasites.
Osmia lignaria propinqua
Western Blue Orchard Bee, Blue Orchard Bee, BOB
Osmia lignaria propinqua is a solitary, cavity-nesting mason bee native to western North America, commonly known as the Western Blue Orchard Bee or BOB. It is a subspecies of the blue orchard bee and is valued as a highly efficient pollinator of early-blooming fruit trees including almonds, cherries, apples, and plums. Females carry dry pollen on the scopa (hairs) beneath the abdomen rather than on leg baskets, and they forage at lower temperatures and for more hours than honey bees. The species is managed commercially in orchards, where it is often deployed alongside honey bees to improve cross-pollination through its tendency to move between trees rather than forage systematically on single plants.
Osmia montana quadriceps
Osmia montana quadriceps is a subspecies of mason bee in the family Megachilidae, described by Cresson in 1878. As a member of the genus Osmia, it is a solitary bee that nests in pre-existing cavities and uses mud to construct brood cells. The subspecies is part of the North American fauna of native mason bees. Mason bees in this genus are valued as pollinators of orchard crops and wild plants, with females carrying pollen on specialized abdominal scopae rather than on leg baskets.
Osmia palmula
Osmia pumila
Osmia pumila is a solitary mason bee native to eastern North America. It is strongly associated with forest habitats, where it performs spring pollination of wildflowers and possibly some timber trees. The species nests in pre-existing cavities such as hollow stems or holes in wood, sealing brood chambers with mud. Research indicates it is one of the most common forest-associated bee species in the eastern United States, with populations increasing as forest cover has regrown since the early 1900s.
Osmia rawlinsi
Osmia rawlinsi is a species of solitary mason bee in the family Megachilidae. It was described by Sandhouse in 1939 and is native to North America. Like other members of the genus Osmia, it is a cavity-nesting bee that uses mud to construct and seal its nest cells. The species is poorly documented in scientific literature, with limited information available regarding its ecology, distribution, and conservation status.
Osmia ribifloris biedermannii
Osmia ribifloris biedermannii is a subspecies of mason bee in the family Megachilidae. The parent species O. ribifloris has been developed as a commercially managed pollinator of highbush blueberry. As a member of the genus Osmia, it exhibits solitary nesting behavior in pre-existing cavities and provisions brood cells with pollen. This subspecies was described by Michener in 1936.
Osmia ribifloris ribifloris
blueberry mason bee
Osmia ribifloris ribifloris is a subspecies of mason bee native to western North America, endemic to regions west of the Mississippi River including Texas, California, and Oregon. It has been developed as a commercially managed pollinator for blueberry crops, particularly rabbiteye and southern highbush blueberries, with 14 years of rearing data documented from the Deep South. The subspecies produces cocoons that can be stored and released for field-scale pollination services.
Osmia simillima
Osmia simillima is a solitary mason bee in the family Megachilidae, native to North America. It nests in twigs, buried wood, and has been observed using oak apple galls as nesting sites. As a member of the genus Osmia, it belongs to a group of ecologically important pollinators that use mud to construct and seal nest chambers.
Osmia subfasciata
Osmia subfasciata is a solitary mason bee in the family Megachilidae, native to Central and North America. It is one of approximately 140 Osmia species present in North America. The species belongs to a genus valued for pollination services, particularly in orchard agriculture. Two subspecies are recognized: O. s. subfasciata and O. s. miamiensis.
Osmia taurus
Taurus Mason Bee
Osmia taurus is a mason bee native to eastern Asia that was accidentally introduced to North America, first recorded in Maryland and West Virginia in 2002. The species has undergone rapid population expansion across the eastern United States, with established populations now confirmed in Canada (Ontario and Quebec). Its spread has been linked to commercial shipments of the intentionally introduced pollinator Osmia cornifrons, with which it is frequently confused. Population growth of O. taurus in the Mid-Atlantic region reached 800% over 15 years, coinciding with documented declines of 76–91% in six native mason bee species.
Osmia texana
Texas Mason Bee, Texas osmia
Osmia texana, commonly known as the Texas mason bee, is a solitary bee species in the family Megachilidae. It is native to Central America and North America. As a member of the genus Osmia, it is a cavity-nesting bee that uses mud to construct and seal its nest cells. Like other mason bees, it is a pollinator of flowering plants, though specific ecological details for this species remain limited in available literature.
Protosmia rubifloris
Prong-faced Slender-Mason
Protosmia rubifloris is a small mason bee in the family Megachilidae, commonly known as the Prong-faced Slender-Mason. It belongs to the genus Protosmia, a group of slender-bodied bees that construct nests using mud or plant resins. The species occurs across Central and North America. As with other megachilids, females carry pollen on the underside of the abdomen rather than on the legs.