Solitary-bees
Guides
Ancylandrena
Ancylandrena is a genus of mining bees in the family Andrenidae, established by Cockerell in 1930. The genus contains five described species, all found in North America. One species, Ancylandrena larreae, is commonly known as the creosote bush ancylandrena due to its association with Larrea tridentata. These are solitary bees that nest in the ground.
Andrena
Mining Bees, Mining Bee
Andrena is the largest genus in the family Andrenidae, containing over 1,500 species of solitary ground-nesting bees. These bees are commonly called mining bees due to their habit of excavating burrows in soil to construct nests. The genus is nearly worldwide in distribution, absent only from Oceania and South America, and is most diverse in temperate regions with Mediterranean climates. Andrena species are important pollinators, with many exhibiting specialized relationships with particular host plants.
Andrenidae
mining bees, miner bees, bulldozer bees
Andrenidae is a large, nearly cosmopolitan family of solitary, ground-nesting bees commonly known as mining bees. The family exhibits exceptional diversity with over 2,000 described species across four subfamilies: Andreninae, Panurginae, Oxaeinae, and Alocandreninae. Most diversity occurs in temperate and arid (warm temperate xeric) regions. The genus Andrena contains approximately 1,700 species, making it one of the most rapidly speciating bee lineages known. Members are typically small to moderate-sized bees with distinctive morphological features including two subantennal sutures on the face—a primitive trait shared with sphecoid wasps—and often possess foveae (depressions) near the upper margin of the eyes. Unlike most bee families, Andrenidae have no known kleptoparasites. Some lineages, particularly within Panurginae, have evolved crepuscular (dusk-active) foraging behavior with enlarged ocelli.
Anthophila
bees
Anthophila is the clade comprising all bees, a monophyletic lineage within the superfamily Apoidea. With over 20,000 described species across seven recognized families, bees represent one of the most ecologically significant groups of insect pollinators. The clade encompasses diverse life histories, from solitary to eusocial species, and exhibits remarkable morphological variation associated with pollen collection and transport. Bees originated from predatory wasp ancestors and evolved specialized adaptations for exploiting floral resources, making them critical components of terrestrial ecosystems and agricultural systems worldwide.
Anthophorini
Digger Bees, Digger Bee, Burrowing Bees
Anthophorini is a large tribe of solitary bees in the family Apidae, commonly known as digger bees or burrowing bees. The tribe contains over 750 species worldwide, with the majority in the genera Amegilla and Anthophora. These bees are ground-nesting specialists, excavating burrows in soil, sand, or clay substrates, often constructing distinctive turrets at nest entrances. Many species exhibit bumble bee mimicry and have specialized associations with particular plant groups for pollen collection.
Augochlora
green sweat bees
Augochlora is a genus of small, metallic sweat bees in the family Halictidae, comprising approximately 127 valid species distributed from southern Canada to Argentina. The genus exhibits remarkable social flexibility, with most species showing facultative eusociality while at least one species, Augochlora pura, is exclusively solitary. Members nest primarily in decaying wood, though some species utilize soil. The genus is divided into three subgenera: Augochlora s. str., Oxystoglossella (formerly Oxystoglossa), and the extinct Electraugochlora known from Miocene Dominican amber.
Calliopsini
Calliopsini is a tribe of mining bees (family Andrenidae, subfamily Andreninae) comprising at least 120 described species across six genera. Members are solitary, ground-nesting bees found primarily in the Americas. The tribe includes the genera Acamptopoeum, Arhysosage, Calliopsis, Callonychium, Litocalliopsis, and Spinoliella.
Calliopsis
mining bees, panurgine bees
Calliopsis is a genus of solitary mining bees in the family Andrenidae, comprising over 80 described species distributed throughout the western hemisphere. These small to medium-sized bees are ground-nesting, with females excavating burrows in sandy or loose soils. The genus includes both polylectic and oligolectic species, with some showing tight specialization to particular pollen hosts such as Prosopis. Several species have been studied in detail for their nesting biology, foraging behavior, and host-parasite relationships with cleptoparasitic bees.
Centridini
oil-collecting bees, oil bees
Centridini is a tribe of large apid bees distinguished by specialized adaptations for collecting floral oils, often from plants of the family Malpighiaceae. Many species possess modified leg structures—either combs of flattened, blunt bristles or velvety pads—for gathering oils, which are used in nest construction and cell provisioning. The tribe includes ground-nesting and cavity-nesting solitary bees with diverse nesting behaviors across the Americas. Members exhibit notable thermal tolerance, with some desert species remaining active at high temperatures when other bees are inactive.
Centris
Oil-diggers
Centris is a genus of approximately 250 large apid bees distributed from the southern United States through South America. Females are specialized oil collectors, possessing morphological adaptations for gathering floral oils from plants, primarily in the family Malpighiaceae, which they use for larval nutrition and cell construction. The genus is sister to the corbiculate bees (honey bees, bumble bees, stingless bees) and represents an important lineage for understanding bee evolution and pollination ecology.
Colletes
plasterer bees, cellophane bees, polyester bees
Colletes is a large genus of solitary ground-nesting bees in the family Colletidae, comprising approximately 470 described species with an estimated total around 700. Adults are small, typically 1–2 cm long, with dense pale hair and distinctive wing venation. Females construct individual underground burrows lined with a unique polyester secretion from the Dufour's gland, creating a cellophane-like waterproof coating that gives these bees their common names. They are among the earliest native bees to emerge in spring and are important pollinators, with many species showing specialized pollen-foraging preferences.
Colletidae
plasterer bees, polyester bees, cellophane bees
Colletidae is a family of solitary bees comprising over 2,000 species across 54 genera and five subfamilies. Members are commonly called plasterer bees or polyester bees due to their distinctive nest cell linings: females apply oral and abdominal secretions that dry into a cellophane-like, waterproof polyester membrane. The family exhibits exceptional diversity in Australia and South America, with over 50% of Australian bee species belonging to this family. Two subfamilies, Euryglossinae and Hylaeinae, uniquely lack external pollen-carrying structures (scopa) and instead transport pollen internally in their crops, feeding larvae with liquid or semiliquid pollen masses. Most species are solitary ground-nesters, though many form dense aggregations, and some exhibit crepuscular activity with enlarged ocelli.
Emphorini
Chimney Bees
Emphorini is a tribe of solitary, ground-nesting bees within the family Apidae. Members are characterized by narrow pollen preferences, with many species exhibiting oligolecty (specialized pollen collection from a restricted range of plant taxa). Nesting behavior varies: some species carry water to soften hard soil during excavation, while others do not. The tribe includes approximately nine genera distributed primarily in the New World, with an amphitropical distribution pattern in some genera.
Eucerini
Longhorn Bees, Long-horned Bees
Eucerini is the most diverse tribe in the family Apidae, comprising over 32 genera and approximately 500 species worldwide. All species are solitary, with females nesting in the ground and males forming characteristic overnight sleeping aggregations on vegetation. The tribe is distinguished by unusually long male antennae, the source of its common name. Eucerini reaches its highest diversity in the Western Hemisphere, with notable specialist pollinators of cucurbits including the economically important squash bees (Peponapis and Xenoglossa).
Euglossini
orchid bees, euglossine bees
Euglossini, commonly known as orchid bees, is a tribe of approximately 200 species in five genera (Euglossa, Eulaema, Eufriesea, Exaerete, and Aglae) distributed throughout the Neotropics. The tribe is unique among corbiculate bees in that non-parasitic members exhibit diverse social behaviors ranging from solitary to primitively eusocial, rather than uniform eusociality. Males are distinguished by their exclusive behavior of collecting volatile fragrances from orchids and other sources, storing them in specialized hind tibial pockets for use in courtship displays. This fragrance collection drives mutualistic relationships with orchids, where male bees serve as exclusive pollinators for many species.
Exomalopsis
Exomalopsis is a genus of solitary bees in the family Apidae, tribe Exomalopsini, comprising nearly 90 described species with many more undescribed. These bees are restricted to the Western Hemisphere, occurring in both Neotropical and Nearctic realms. Species nest communally in soil, excavating deep tunnels with branching underground pathways leading to individual brood cells. The genus is notable for its complex associations with kleptoparasitic cuckoo bees and parasitoid wasps.
Gaesischia
Gaesischia is a genus of bees in the family Apidae, tribe Eucerini, established by Michener, LaBerge, and Moure in 1955. Members of this genus are long-horned bees, a group characterized by elongated antennae in males. The genus is part of the diverse bee fauna of the Americas, with species distributed primarily in South America. Gaesischia species are solitary and nest in the ground, contributing to pollination of native flora.
Habropoda
digger bees, silver digger bees
Habropoda is a genus of solitary, ground-nesting bees in the family Apidae, tribe Anthophorini, comprising at least 50 described species. These bees are distributed across North America and Asia, with notable species including the silver digger bee (H. miserabilis) in western North America and the blueberry bee (H. laboriosa) in the southeastern United States. Research on Habropoda has contributed significantly to understanding chemical communication in bees, particularly regarding sex pheromone composition and exploitation by nest parasites.
Hoplitis
Small Mason Bees
Hoplitis is a large genus of solitary bees in the family Megachilidae, tribe Osmiini, comprising over 380 described species distributed primarily across the Palaearctic region. These bees are commonly known as small mason bees and exhibit diverse nesting strategies including burrows in soil, pre-existing cavities in wood or stone, and insect borings in dead wood. Many species are pollen specialists (oligolectic), with documented associations to specific plant genera including Allium, Reseda, Astragalus, Onosma, and others. The genus demonstrates remarkable biogeographic patterns, including disjunct distributions spanning thousands of kilometers between European and Central Asian populations.
Hylaeus
Masked Bees, Yellow-faced Bees
Hylaeus is a large, diverse genus of solitary bees in the family Colletidae, commonly known as masked bees or yellow-faced bees. The genus contains over 500 species with cosmopolitan distribution, reaching peak diversity in subtropical Australia and the Hawaiian Islands. These bees are distinguished by their nearly hairless, wasp-like appearance and unique method of transporting nectar and pollen internally in a crop rather than externally on body hairs. Many species nest in pre-existing cavities such as hollow stems, beetle borings in wood, or abandoned galls.
Lithurgopsis
northern cactus woodborer bees
Lithurgopsis is a genus of solitary bees in the family Megachilidae, subfamily Lithurginae. These bees are commonly referred to as "northern cactus woodborers" due to their specialized association with cactus wood for nesting. The genus contains at least nine described species distributed across North America, with documented occurrences in the southwestern United States and Mexico. Species within this genus exhibit specialized nesting behaviors, excavating tunnels in cactus stems and provisioning cells with pollen and nectar.
Macropidini
Macropidini is a tribe of bees within the family Melittidae, subfamily Melittinae. These bees are solitary and ground-nesting, with most species belonging to the genus Macropis. They are notable for their specialized oil-collecting behavior, gathering floral oils from Lysimachia (Primulaceae) flowers to provision their nests. This oil-collecting adaptation is rare among bees and represents a distinctive ecological specialization.
Megachilinae
mason bees, leafcutter bees, carder bees
Megachilinae is the largest subfamily of bees within the family Megachilidae, comprising mason bees, leafcutter bees, and carder bees. These bees are characterized by their unique nesting behaviors: leafcutters use circular pieces of leaves or petals to line brood cells, masons construct nests from mud or plant resins, and carders collect plant fibers. Unlike most bees, females carry pollen on specialized scopal hairs located on the underside of the abdomen rather than on the hind legs. The subfamily includes numerous genera distributed globally, with species exhibiting diverse habitat preferences from deserts to tropical forests.
Melissoptila
Melissoptila is a genus of bees in the family Apidae, tribe Eucerini. These are long-horned bees characterized by elongated male antennae. The genus occurs in the Americas, with documented records from the Caribbean and South America. Species in this genus are solitary and ground-nesting.
Melitoma
chimney bees
Melitoma is a genus of solitary bees commonly known as chimney bees, comprising approximately 11-13 described species. Members of this genus are classified within the family Apidae, tribe Emphorini, and are characterized by their distinctive nesting behavior involving the construction of chimney-like turrets at nest entrances. The genus occurs in the Nearctic and Neotropical regions, with species documented from North America through Central and South America.
Nomia
sweat bees, alkali bees
Nomia is a cosmopolitan genus of sweat bees in the family Halictidae, comprising approximately 130 species worldwide. These moderate-sized bees are characterized by opalescent bands on the metasoma in many species. They are ground-nesting bees, with most species nesting solitarily and some exhibiting communal nesting where females share a nest entrance but lack queen or worker castes. The genus includes the intensively managed alkali bee (N. melanderi), which is commercially used for alfalfa pollination in the western United States.
Osmiini
mason bees, leafcutter bees, resin bees
Osmiini is a tribe of solitary bees within the family Megachilidae, comprising approximately 19 genera and at least 1,000 described species. Members are commonly known as mason bees, leafcutter bees, and resin bees, reflecting their diverse nest construction behaviors. The tribe exhibits considerable diversity in nesting ecology, with species utilizing preexisting cavities in dead wood, hollow stems, rock crevices, empty snail shells, or excavated soil burrows. Nesting materials vary by lineage and include chewed leaves, mud, resin, and combinations with pebbles or sand grains. Pollen foraging strategies range from strict oligolecty on single plant genera or families to broad generalization across numerous plant families.
Panurginae
Panurginae is a subfamily of solitary bees within family Andrenidae, comprising 33 genera in 7 tribes. The group is particularly diverse in the New World, with greatest representation in arid and temperate regions, and occurs in the Palearctic and Africa in the Old World. Members are strongly associated with xeric and sandy habitats. Most species are oligolectic, exhibiting specialized pollen-foraging relationships with particular host plants.
Perditina
Fairy Bees, Goblin Bees, False Goblin Bees
Perditina is a subtribe of small bees within the family Andrenidae, commonly known as Fairy Bees, Goblin Bees, and False Goblin Bees. These bees are among the smallest bees in North America, with many species measuring only a few millimeters in length. The subtribe includes the genus *Perdita*, which is extraordinarily diverse with over 800 described species, many of which are specialized pollen collectors on specific host plants. Perditina bees are primarily solitary ground-nesters and are important pollinators, particularly in arid and semi-arid regions. Their minute size and often striking metallic coloration distinguish them from other bee groups.
Protoxaea
Protoxaea is a genus of mining bees in the family Andrenidae, containing at least three described species. The genus is notable for the well-documented territorial behavior of males in at least one species, Protoxaea gloriosa. These bees are associated with flowering plants in arid environments and exhibit complex mating systems involving male territoriality and female resource collection.
Pseudopanurgus
mining bees
Pseudopanurgus is a genus of mining bees in the family Andrenidae, established by Cockerell in 1897. The genus contains at least 32 described species, though some sources suggest over 130. These bees are small, ranging from 3 mm to 10 mm in body length. Their taxonomic status has been debated, with some treatments recognizing them as a subgenus of Protandrena.