SUNY ESF
Bee List
As of summer 2026, Bee Campus researchers have recorded 112 species of bees on the SUNY ESF main campus in Syracuse – and our list is ever-growing! There are just over 450 bee species known from New York State, meaning that the 20-acre ESF campus hosts nearly a quarter of the state’s bee diversity! We attribute this to the amount of native, pesticide-free landscaping on campus, much of it specifically catered towards native pollinators and their specialized resource needs. Additionally, connectivity to other patches of habitat, such as Oakwood Cemetery and nearby neighborhoods, likely helps pollinators travel through the landscape to find our campus and offers further nesting habitat.
Here you can explore the bees that call our campus home. Use the dropdown boxes to see further information about each bee, including our assessment of how common each species is on our campus based on our data and search effort, and their ecology. Each species name also links to an external page to learn more and see photos of that bee. Visit our iNaturalist project to view observations of these species from campus submitted by researchers and students.
This is the most current version of the campus species list. Note there have been changes since the 2025 inventory report. Information compiled by Molly Jacobson, pollinator ecologist.
Bees of SUNY ESF
Andrenidae
Andrena – the mining bees
Mining bees are a common and diverse group of solitary, ground-nesting bees that fly primarily in spring. They are often associated with forested habitats, and frequently visit trees and shrubs including commercially important crops like apples and blueberries. Many are pollen specialists, and some form large nesting aggregations of anywhere from dozens to millions of individuals.
Mustard mining bees are pollen specialists on certain spring-blooming plants in the mustard family (Brassicaceae), particularly toothworts (Cardamine) and rockcress (Arabis). However, they will also visit some non-native mustards like garlic mustard and yellow rocket. On campus, it was recorded using the latter. The ability to use a non-native host is not common among specialists.
Status on campus: Very Uncommon
Long-lipped mining bees are spring-flying generalists that are associated with sandy soil. Their name comes from their long labral process, a feature on the labrum or ‘upper lip’ of the bee, visible under the microscope. It is known to visit crabapple and dogwood on campus.
Status on campus: Very Uncommon
The short-tongued mining bee is an uncommon specialist on sumacs (Rhus), particularly staghorn and smooth sumac that flower in July. It flies in midsummer when few other mining bees are active. On campus, it has only been seen once, nectaring on mountain mint.
Status on campus: Rare
Carlin’s mining bee is a common spring generalist that visits a wide variety of trees, shrubs, and herbaceous flowers. It is a frequent visitor to apple orchards and other spring-blooming fruit crops. It resembles a bumblebee, but is more slender, lacks pollen baskets, and has a shiny abdomen. While it is regionally common, it has only been seen on campus twice, on willows.
Status on campus: Uncommon
Forbes’s mining bee is a fairly common spring generalist, though is often overlooked due to the difficulty in separating it from similar species. On campus it has primarily been recorded on willow and crabapple.
Status on campus: Uncommon
The hawthorn mining bee is, despite its name, a generalist pollinator, although it does tend to visit trees and shrubs. It is active in late spring to early summer, and can be quite abundant in forested landscapes. On campus It has most often been recorded on fragrant sumac, hawthorn, and ninebark.
Status on campus: Common
Cresson’s mining bee is a fairly common spring generalist, visiting a wide variety of trees, shrubs, and herbaceous flowers. The male is among the most distinctive of all male mining bees in our area (which are otherwise usually difficult to tell apart); the entire lower half of the face is yellow, whereas most others are black or only have yellow on the broad saddle-shaped portion of the face called the clypeus.
Status on campus: Fairly Common
Dunning’s mining bees are a common sight in the spring garden. They are generalist flower visitors and often nest in yards. They are fairly distinctive, being one of only a few local bees with orange hair on the head and thorax and a completely black abdomen. On campus, it has been recorded on willow and crabapple.
Status on campus: Fairly Common
Orange-legged mining bees are fairly common spring generalists. They are one of only a few mining bees with orange back legs. On campus, they are usually seen on fragrant sumac and crabapple.
Status on campus: Uncommon
The hairy-banded mining bee is among our most distinctive northeastern mining bees. It is covered in fluffy yellow hair. This bee is active in late summer and early fall, and is a specialist on goldenrods and to a lesser extent asters. It is less specific in its habitat and soil preferences than some other goldenrod specialists, making it easy to find in a variety of places with patches of goldenrod. On campus it has been seen only once, though there are plenty of its host plants.
Status on campus: Very Uncommon
The imitator mining bee is a fairly common spring generalist. It gets its name from the variability of many microscopic features that identify it. It is seen frequently on campus, usually visiting fragrant sumac, willow, or crabapple.
Status on campus: Common
Bare dogwood miners are one of four specialists in the northeast on shrubby dogwoods (e.g., red-osier, gray, silky). Unlike the other three, this bee is quite distinctive, being almost entirely hairless apart from the pollen-collecting hairs on its legs. It is active from late spring into early summer when dogwoods are in bloom. On campus, it can be seen on gray dogwood.
Status on campus: Very Uncommon
The toothed mining bee is a fairly common generalist active in early to mid-spring. It is named for the male having a distinct ‘tooth’ on the underside of the mandible, shared by only a few other species. On campus this bee is most often seen on crabapple, willow, and sugar maple.
Status on campus: Uncommon
The Milwaukee mining bee is an uncommon spring generalist that visits a variety of trees and shrubs. It is one of our most distinctive mining bees, having rusty orange hair on the thorax and first two abdominal segments, and black everywhere else. It has only been seen once on campus.
Status on campus: Rare
Miserable mining bees are common early spring generalists, visiting many trees and shrubs. Females can often be distinguished with a close eye, as they have a shiny, almost entirely unpitted clypeus, the lower central part of the face. Males have this area yellow, one of the only mining bees at this time to do so. On campus they have been recorded from a number of woody plants such as willow, sugar maple, gray dogwood, and crabapple.
Status on campus: Common
Nason’s mining bee is a common and often abundant spring generalist that visits a wide variety of trees, shrubs, and herbaceous flowers. It is fairly recognizable, being small in size, with gray hair on the thorax and thick white hair bands on the abdomen. On campus it has typically been recorded on crabapple, hawthorn, dandelion, and willow.
Status on campus: Fairly Common
The snowy mining bee is a fairly common generalist active in late spring and early summer. It closely resembles related species like Dunning’s mining bee and the neighborly mining bee. On campus, it has been recorded on winterberry holly and fragrant sumac.
Status on campus: Very Uncommon
The cloudy-winged mining bee is active in late summer and fall, and is a specialist on goldenrods. It is a fairly distinctive bee, being rather small with dark wings and white hair bands on the abdomen. Along with the hairy-banded mining bee, it is one of the more likely goldenrod specialists to encounter. It seems to prefer forest edges and openings.
Status on campus: Very Uncommon
The perplexing mining bee is an uncommon spring generalist, visiting many trees, shrubs, and herbaceous flowers. It closely resembles several other species of mining bee like the neighborly mining bee and snowy mining bee. Central New York is near its northern range limit, and is much less common here than further south. It has been seen only once on campus, on hawthorn.
Status on campus: Rare
The peaceful mining bee is a fairly common specialist on goldenrods, and to a lesser extent asters. It is active in late summer. It closely resembles some other goldenrod bees, particularly the simple mining bee, from which it cannot be separated by eye. Males of both species have a yellow clypeus (lower central portion of face), which few other mining bees at this time have.
Status on campus: Very Uncommon
The plated mining bee is one of four specialists on shrubby dogwoods (e.g., red-osier, silky, gray). It is active in early summer when dogwoods bloom, and seems to be associated with forested landscapes. On campus, it has been recorded on gray dogwood.
Status on campus: Very Uncommon
Cherry mining bees are uncommon spring generalists that visit a variety of trees, shrubs, and herbaceous flowers in forested landscapes. Central New York is near its northern range limit, so it is much less common here than further south. On campus, it has been found on crabapple and hawthorn.
Status on campus: Uncommon
The chestnut mining bee is a very rare specialist on chestnuts and chinquapins (Castanea). It has likely suffered severe loss of habitat due to the chestnut blight which left the American chestnut functionally extinct by the mid-1900s. Prior to 2023, this bee had not been seen in New York since 1904. There are only two known populations in the state, both of which were discovered by ESF’s Bee Lab. One of these populations occurs at the Lafayette Rd Experiment Station in Syracuse, where hundreds of chestnuts are grown for the American Chestnut Research & Restoration Project. Read more about this exciting discovery here.
Status on campus: This species does not occur on the main campus, but at another ESF property.
The simple mining bee is an uncommon specialist on goldenrods, and to a lesser extent asters. It is active in late summer. It closely resembles some other goldenrod bees, particularly the peaceful mining bee, from which it cannot be separated by eye. Males of both species have a yellow clypeus (lower central portion of face), which few other mining bees at this time have.
Status on campus: Very Uncommon
The neighborly mining bee is a common and often abundant spring generalist, visiting a wide variety of trees, shrubs, and herbaceous flowers. They resemble some other mining bees like the perplexing mining bee and snowy mining bee. This species is likely the most abundant mining bee on our campus, most frequently seen on crabapple, fragrant sumac, willow, and hawthorn.
Status on campus: Common
Wilkes’s mining bee is a common specialist on clovers (Trifolium). It was introduced to North America from Europe sometime in the late 1800s and can now be found anywhere with clover-filled lawns and meadows. It is the most abundant mining bee active in midsummer.
Status on campus: Fairly Common
Apidae
Anthophora – digger bees
Digger bees are medium to large-sized hefty bees that primarily nest in the ground, sometimes forming large aggregations on vertical riverbanks where the soil is moist. They are generalist long-tongued pollinators and have a distinctive quick, zipping flight around flowers, never staying still for long.
The orange-tipped wood-digger bee is the only common digger bee in upstate New York. Unlike other digger bees, it nests in rotting wood. It can best be found visiting tube-shaped flowers like great blue lobelia, jewelweed, and penstemon; the latter is where it is typically seen on campus.
Status on campus: Uncommon
Apis
Apis – honey bees
Honey bees are the most well-known bees in the world. For most, the honey bee is what comes to mind when bees are mentioned, though in reality they make up only 9 of the >20,000 known bee species. Only one is distributed worldwide, due to human intervention – the western honeybee, native to Europe and Asia. Honey bees are one of only two groups of bees (the other being stingless bees, the Meliponini) that produce honey in any appreciable amount; the vast majority of bee species make none at all.
Western honeybees are widespread from coast to coast. The vast majority come from human-managed hives, though feral colonies in tree hollows do occasionally occur. Honeybees have advanced eusocial behavior, living in large perennial colonies with distinct queen and worker castes. In some places they can be so abundant as to displace native bees from preferred floral resources, and can spread diseases to native bumblebees. They can be seen on almost any type of flower, any time of year except the depth of winter.
Status on campus: Common
Bombus
Bombus – bumblebees
Bumblebees are likely our most familiar native bees. Similar to honey bees, they live in colonies with workers and a queen, but their social structure is not as rigid and colonies last only a single year – thus they have what is known as primitive eusocial behavior. Some species nest below ground in old rodent burrows, while others nest in thatched grass at or above ground level. Many North American bumblebee species are in severe decline. Find bumblebee-friendly native flowers for your garden at this website.
The black-and-gold bumblebee is distinctive at first glance by its enormous size; queens are so large and bulky they often have trouble clinging onto flowers. Males have large eyes and patrol territories from high perches. New York represents the edge of their range, and they are extremely rare or absent in the New England states. They are ranked S2 (imperiled) in New York; Onondaga County is a stronghold for this species in the state. They are a long-tongued species, and on campus are typically seen on vetch, penstemon, wild basil, asters, willow, and wild bergamot. It is believed they nest in the adjacent Oakwood Cemetery.
Status on campus: Fairly Common
Two-spotted bumblebees are common medium-tongued bumblebees that visit a variety of deep flowers. They typically nest below ground, and their colony cycle is rather short, with males appearing earlier in the summer than those of other bumblebee species. On campus, they are usually seen visiting wild bergamot, penstemon, wild indigo, flowering raspberry, buttonbush, clover, and shrubby St. John’s wort.
Status on campus: Common
Lemon cuckoo bumblebees are New York’s most frequently seen parasitic bumblebee. They lack pollen baskets and do not forage for pollen; instead, a female invades the nest of its host species, usurps the host queen, and manipulates the host workers into raising its young. There are no workers or queens, just females and males. Lemon cuckoo bumblebees use two-spotted bumblebees, half-black bumblebees, and common eastern bumblebees as hosts, making them relatively stable.
Status on campus: Uncommon
Brown-belted bumblebees are common, short-tongued bumblebees that visit many flowers and are a frequent sight in backyard gardens. They are sometimes mistaken for the endangered rusty-patched bumblebee (extirpated from NY) because of the brown saddle-shaped band on their abdomen. Males have large eyes, one of only a few species in our area to have this. This bumblebee is often seen on common milkweed, purple coneflower, and Joe-Pye weed, and on campus frequents the anise hyssop, mountain mint, purple coneflower, sneezeweed, and buttonbush.
Status on campus: Common
This is the most frequently encountered bumblebee in the eastern United States. In most cases they represent the vast majority of bumblebees seen in the average garden. They have adapted well to human-modified landscapes, and their populations have been increasing over the last century, potentially replacing other bumblebee species in some places. They are also important agricultural pollinators, used to pollinate both outdoor and greenhouse-grown crops. On campus they are ubiquitous and are likely to be one of the earliest bees seen in the spring and last in the fall.
Status on campus: Common
Confusing bumblebees are a fairly common medium-tongued species that is generally associated with forested landscapes. Their flight season is shorter than some other bumblebees, not typically being seen past midsummer. Males, with their long shaggy golden-yellow hair, can often be seen nectaring on milkweed. This species has only been seen once on campus, on black cohosh.
Status on campus: Rare
Yellow-banded bumblebees are an uncommon short-tongued bumblebee species associated with forested landscapes. It was once broadly distributed across much of the northern and eastern US and Canada but has declined significantly. In much of the northeast and Appalachia it is now most often seen in high elevation areas, but it appears to be more widespread in New York and is ranked S3 (vulnerable) here. They resemble black-and-gold bumblebees but are smaller, with fluffier hair and a shorter face. This species has only been seen on campus once, on goldenrod.
Status on campus: Rare
Half-black bumblebees are a fairly common medium-tongued species that visit many flowers, particularly deep flowers. They may be in decline in some states, though are ranked S5 (stable) in New York. On campus, they are primarily seen on penstemon and wild indigo.
Status on campus: Fairly Common
Creatina
Small carpenter bees are small, usually metallic blue stem-nesting bees. They bore into the spongy pith of many senesced garden perennials and woody plants, and are a good reason to leave your garden a little messy – they need dead standing cut stems that persist at least a full year. There are four species of small carpenter bee in the northeast, all of which look very similar.
This is the most commonly encountered of the small carpenter bees, and in suburban areas can be quite abundant. In the wild they frequently nest in the broken canes of brambles like blackberries, and in sumac stems, though they use many garden plants too, like coneflowers and hydrangea. They exhibit a quasi-social behavior where a mother and her daughters share a nest and daughters sometimes act as workers, making them a model organism to study the evolution of social behavior in bees. This species is abundant on campus.
Status on campus: Common
Epeolus – cellophane-cuckoo bees
Cellophane-cuckoos are nest parasites of cellophane bees (Colletes). They infiltrate the host bee’s nest, puncture the plastic-like nest cell, and lay an egg inside. Their larva then kills the host larva and develops on the provisions the host bee collected. In New York, these bees are uncommon, and can sometimes be mistaken for the somewhat more common longhorn-cuckoos (Triepeolus).
This cuckoo bee is a parasite on eastern spine-shouldered cellophane bees (Colletes simulans armatus), which is a goldenrod & aster pollen specialist. Thus, its cuckoo is seen in late summer and early autumn. This is the most frequently encountered cellophane-cuckoo species in the northeast.
Status on campus: Very Uncommon
Melissodes – longhorned bees
Longhorned bees are solitary, ground-nesting bees that are typically active from mid-summer into autumn. In the northeast, males are distinctive for their extremely long antennae (though in other parts of the country there are several similar-looking groups). Most species are specialists, particularly of plants in the aster family.
Agile longhorned bees are uncommon specialists on sunflowers (Helianthus) and a few related plants. Along with the closely related, and difficult to separate visually, dark-veined longhorned bee (M. trinodis), they can be common in community gardens and backyards with lots of sunflowers. They are active in late summer. On campus, they have only been observed during the one year when annual sunflowers were planted.
Status on campus: Very Uncommon
Thistle longhorned bees are fairly common specialists on thistles (Cirsium). Unlike most other pollen specialists, they have adapted to use invasive thistle species as host plants alongside the less-common natives. Males can be found on a variety of flowers, and on campus have been recorded on purple coneflower and spotted knapweed.
Status on campus: Uncommon
Drury’s longhorned bees are fairly common goldenrod specialists that fly late in the season, typically late summer into mid-autumn. Their black and orangey-gold color pattern is reminiscent of the Halloween season – and they might still be active then! Despite having a lot of goldenrod, it has only been seen once on campus.
Status on campus: Very Uncommon
The valiant longhorned bee is an uncommon specialist on plants in the aster family, especially sunflowers and coneflowers. It is very similar to Melissodes subillatus, but that species flies primarily in midsummer, while the valiant longhorned bee typically is found in late July – still earlier than many other longhorned bees. On campus, it has been recorded on mountain mint and threadleaf coreopsis.
Status on campus: Very Uncommon
Nomada – nomad bees
Nomad bees are the most frequently encountered cuckoo bees in the northeast, and are distinctive in their brick-red coloration and hairless appearance. Most are nest parasites of mining bees (Andrena) and can often be seen hovering close to the ground in forested areas searching for nests. The majority are active in spring, like their hosts, but a handful fly in summer and fall.
This is a yet-unidentified species of nomad bee in the broad, difficult taxonomic group of species with two teeth on their mandible. Many nomad bees fall into this category and there do not yet exist confident ways to identify most of them. While nomad bees in general are common, only a few have been seen on campus, and only one of this group.
Status on campus: Rare
This is a yet-unidentified nomad bee that is likely the pygmy nomad bee or a similar species. The host bee for pygmy nomad bees is not known, but presumed to be a species of mining bee.
Status on campus: Rare
Xylocopa – carpenter bees
Carpenter bees are some of our largest native bees, reaching an inch long. Their name comes from their industrious ability to bore circular holes into wood or plant stems, forming galleries that can be used over multiple generations. They are generalist flower visitors, and often exhibit nectar-robbing behavior, cutting a hole in the base of a flower too deep for them to access so they can stick their tongue in to reach the nectar. In the northeast, only one species of carpenter bee occurs.
Eastern carpenter bees are common and recognizable, especially males with their white faces and large green eyes that frequently hover in front of humans while guarding territory. These wood-nesters have weakly social behavior, where offspring temporarily share a nest with their parents and help forage. Carpenter bees are most frequently seen in spring, after adults emerge from overwintering, and again in late summer and fall when the next generation matures.
Status on campus: Common
Colletidae
Colletes – cellophane bees
Cellophane bees get their name from the unique, plastic-like natural polymer they secrete and use to line their nest cells to waterproof them. They have a short, forked tongue that they use to apply this secretion to the inside of the nest. Instead of providing a solid ball of pollen for their larvae, the provisions are a liquid mix of pollen and nectar. In the northeast, cellophane bees are ground-nesting and usually fairly large in size, typically with bold stripes on the abdomen. Many are pollen specialists.
Unequal cellophane bees are one of the most frequently encountered springtime bees. They are known for their often large nesting aggregations on hillsides, in cemeteries, and along hiking trails. They are large, honeybee-sized brown bees with striped abdomens, and are generalists, visiting many different springtime flowers. On campus, large numbers are seen on fragrant sumac, willow, and redbud. There are several nesting aggregations of unequal cellophane bees in the cemetery adjacent to campus.
Status on campus: Common
Eastern spine-shouldered cellophane bees are relatively common pollen specialists on goldenrod and to a lesser extent, asters. They can be seen in late summer and early autumn. On campus, males have been recorded on boneset.
Status on campus: Very Uncommon
Hylaeus – masked bees
Masked bees are common and distinctive solitary bees that are often overlooked due to their very small size and hairless, wasp-like appearance. Females have two light-colored triangle-shaped marks on the face, while males have a full ‘mask’. Unlike other bees, they do not carry pollen on their bodies; rather, they eat the pollen and store it in their crop to regurgitate it in the nest later. Like cellophane bees, they line their nest with a natural plastic, however masked bees nest in pre-existing cavities like hollow stems or holes in wood.
H. affinis is a fairly common species of masked bee that can be found on a wide variety of flowers during the summertime. Females cannot be easily separated from some other masked bee species. On campus, males have been recorded on hemp dogbane, mountain mint, fleabane, and Queen Anne’s lace.
Status on campus: Uncommon
H. illinoisensis is a fairly common species of masked bee that can be found on a wide variety of flowers during the summertime. Females cannot be easily separated from some other masked bee species. On campus, males have primarily been recorded on flat-topped goldenrod and boneset.
Status on campus: Uncommon
The hairy masked bee is an introduced species from Europe that was first recorded in the United States in Ithaca, New York in the 1990s. It has since spread across the Great Lakes region. Unlike native masked bees, its facial markings are off-white, not yellow, though it is not the only species to have this. This species is relatively abundant on campus, which is rather unusual; they have been found on many plants, most often on mountain mint, goutweed, buttonbush, and boneset.
Status on campus: Fairly Common
The slender-faced masked bee is an introduced species from Europe that was first recorded in the United States in Fargo, North Dakota in 1912, and has since spread across the continent. Unlike native masked bees, its facial markings are bright white. These bees are patchily distributed and can be absent from many places, but it tends to be more common in urban areas. It is believed to be a pollen specialist on non-native sweet clover (Melilotus), although it has been recorded on campus on a wide variety of plants, particularly flat-topped goldenrod. It is likely the most abundant bee on the ESF campus.
Status on campus: Common
Cresson’s masked bees are exceptionally small bees, being just over 1/8 inch long – small even for a masked bee. Hovering around a flower they are easily mistaken for a small wasp or fly. They are common generalists, and on campus have been recorded on many flower species, particularly flat-topped goldenrod and goutweed.
Status on campus: Fairly Common
Modest masked bees are likely the most common masked bee in the northeast, although they are very similar in appearance to some other species and therefore cannot be easily identified. They can be found on many different flowers, and on campus males have been primarily recorded on flat-topped goldenrod and fleabane.
Status on campus: Uncommon
The little masked bee is a very recently introduced species from Europe, having first been seen in the United States in 2015. Females look similar to other masked bees, but males are distinctive in having white markings on the face contrasting with mostly yellow legs. They are well-established on campus, and the population at ESF was only the second record in New York for this bee. It will likely begin showing up in other parts of the state soon. On campus they have most often been recorded on flat-topped goldenrod, goutweed, and hoary alyssum.
Status on campus: Fairly Common
Halictidae
Augochlorini and Agapostemon – green sweat bees
There are several kinds of green sweat bees in the northeast, most of which look similar to the naked eye though they are not all related to each other. These insects look like glittering jewels on flowers, and are nearly unmistakable among our local bees. Some flies and wasps are also metallic green, but have a very different body shape, behavior, and lifestyle.
Silky striped sweat bees are fairly large, all-green bees that can be found in many habitats including yards and gardens. These bees are ground-nesters and generalist flower visitors. They could be mistaken for other species of striped sweat bee like the fine striped sweat bee (A. subtilior) and brown-winged striped sweat bee (A. splendens) but both of these are sand-associated and less likely to be in urban areas, especially if soils are not sandy. On campus, they have primarily been seen on fragrant sumac and goldenrod.
Status on campus: Uncommon
Bicolored striped sweat bees are one of our most recognizable native bees. They have a green head and thorax, with a black and white striped abdomen. They are common suburban bees that nest communally in the ground, often in lawns, and are active most of the season. On campus, they have been seen mainly on eastern prickly pear cactus, purple coneflower, oxeye daisy, and lance-leaved coreopsis.
Status on campus: Fairly Common
Pure green sweat bees are rather small, completely green solitary bees that nest in rotting logs. While they can be found in a variety of habitats foraging, and are often abundant, they are associated with forested landscapes and require forests nearby to nest. Adult females overwinter in or beneath logs. On campus, they have most often been found on bottlebrush buckeye, goldenrod, sumac, and sneezeweed.
Status on campus: Fairly Common
Golden-green sweat bees are small green bees that nest in the ground and have primitively eusocial behavior, forming small colonies. They can be abundant in many habitats, including suburban and urban areas, and visit a wide variety of flowers. They are the smallest of the green bees in the northeast. On campus, they are frequently seen on goldenrod, asters, mountain mint, great blue lobelia, and the herbs in the Quad patio planters.
Status on campus: Common
Epauletted sweat bees are medium-sized, shiny green bees that nest in the ground. They are slightly bulkier than the smaller green bees but not as large as the striped sweat bees. They visit a variety of flowers, but are never as abundant as other green bees – typically just one or two are ever seen at once. This species has only been seen once on campus, on goldenrod.
Status on campus: Rare
Halictus – furrow bees
Furrow bees are non-descript, usually black bees with white stripes on the abdomen. They nest in the ground and are generalist flower visitors. While not remarkable in appearance, they can be very abundant in some habitats, including urban areas, making them important pollinators of many plants. Furrow bees also exhibit socially plastic behavior; depending on climate and other factors, they may develop solitary nests or social nests with a queen and workers, within the same species. Unlike hive-dwelling honeybees and bumblebees, worker furrow bees can still reproduce and may either replace a lost queen, usurp her, or leave the nest to form their own if the queen cannot maintain control.
Confusing furrow bees are small, olive-colored metallic bees that are fairly common on a variety of flowers. They are often one of the earliest bees seen in spring, and are active all season. Their name refers to the ease of mistaking this bee to the similar metallic sweat bees (Lasioglossum subg. Dialictus) – though, confusing furrow bees have stripes of hair on the abdomen that they lack. On campus, they have most often been recorded on flat-topped goldenrod, sweet pepperbush, and swamp vervain.
Status on campus: Fairly Common
Ligated furrow bees are among the most abundant bees in summertime. They can be seen from spring through fall, but become some of the most common bees on flowers in midsummer due to the production of workers in their colonies. They are small, black bees with striped abdomens, and a noticeably large head. On campus, they have been recorded on many plants, but most frequently on blazingstar, sneezeweed, coreopsis, and boneset.
Status on campus: Common
Orange-legged furrow bees are somewhat larger and less abundant than ligated furrow bees, but no less common. Despite the name, their legs are not noticeably orange. They often nest in yards and manicured areas, sometimes even preferring landscaping stones as substrate. On campus, they have primarily been seen on fragrant sumac, willow, and chives.
Status on campus: Fairly Common
Lasioglossum – black sweat bees
Lasioglossum is the most diverse genus of bees worldwide, with over 1800 species. They have a wide range of lifestyles, from solitary to primitively eusocial to parasitic, and while most nest in the ground and are generalists, there are exceptions. Several subgenera (groups) of this genus are dark in color, while one (Dialictus, discussed below) contains metallic species. The black species range from small to fairly large in size, and many have white-banded abdomens similar to furrow bees. They get their name from their tendency to land on humans to drink their sweat.
Band-legged sweat bees are medium-sized dark bees with hair bands on the abdomen, though not as bold as in some other species. They are fairly common and can be found on a variety of flowers; on campus, they have been recorded on willow, sugar maple, crabapple, and colt’s foot.
Status on campus: Uncommon
Leathery sweat bees are similar in appearance to other large dark sweat bees with white bands on the abdomen. Males are fairly distinctive in having very long mandibles and yellow color on the lower face. While this species is generally common, it has only been found once on campus, on swamp vervain.
Status on campus: Very Uncommon
Fox’s sweat bee is a fairly common, small black bee without bold white abdominal bands. It is generally active from spring into midsummer. It has only been recorded once on campus, on fragrant sumac.
Status on campus: Rare
White-banded sweat bees are fairly large black sweat bees with bold white bands on the abdomen. While it was previously thought to be Holarctic (naturally occurring in northern latitudes across both North America and Eurasia), it is now believed to be introduced in North America. On campus, they have been recorded on lanceleaf coreopsis and sow thistle.
Status on campus: Very Uncommon
Bull-headed sweat bees are fairly large black sweat bees with bold white bands on the abdomen. They are an introduced species from Europe. Males have somewhat larger heads than other species. On campus, it has only been seen once, on boneset.
Status on campus: Very Uncommon
Lasioglossum subgenus Dialictus – metallic sweat bees
The metallic sweat bees are among the most abundant and diverse bees in the northeast.
They are small – sometimes very small – and can be metallic olive, blue, or gold in
color. Most are ground-nesting and primitively eusocial, with small colonies, while
some are parasitic on other Dialictus species. They are considered one of the most
difficult groups of bees to identify to species, as the features that separate them
are minute and take extensive experience to distinguish. Most of our campus specimens
were sent to regional experts for verification.
Information on Dialictus species compiled with assistance from David Mantack, Southern
Connecticut State University & Connecticut Agricultural Experiment Station.
The admirable sweat bee is an uncommon species of metallic sweat bee. On campus it has been recorded once, on fragrant sumac.
Status on campus: Very Uncommon
Deep blue sweat bees are distinctive in being entirely metallic blue, including the abdomen (which is typically dark in other metallic sweat bees). They form small colonies in rotting logs, making them associated with forested landscapes. This species has been seen once on campus, on bottlebrush buckeye.
Status on campus: Very Uncommon
Cresson’s sweat bee is a fairly common species of metallic sweat bee. It nests in rotting logs and is typically associated with forested landscapes. It is widely distributed from coast to coast. On campus, it has been recorded once, on flowering raspberry.
Status on campus: Very Uncommon
The nightmare sweat bee is a common species of metallic sweat bee. It can be exceptionally abundant in some areas. Its name comes from the frequent difficulty in identifying this common yet nondescript bee. On campus, it is the most abundant metallic sweat bee alongside the lineated sweat bee (L. lineatulum) and has been recorded on a variety of plants including fragrant sumac, chives, crabapple, scarlet pimpernel, asters, and bedstraw.
Status on campus: Common
The Gotham sweat bee is an uncommon species of metallic sweat bee. It has a shorter flight period than most other Dialictus, being active only from spring into early summer. On campus it has been recorded from bottlebrush buckeye, black chokeberry, and fragrant sumac.
Status on campus: Very Uncommon
The wide-mouthed sweat bee is a very uncommon species of metallic sweat bee. While the northeast likely comprises the core of its range, it is scarce and never abundant. It has an unusually wide head that only a few other Dialictus species share. On campus, it has been found on hydrangea, northern bush-honeysuckle, and fragrant sumac.
Status on campus: Very Uncommon
Hitchens’s sweat bee is a fairly common species of metallic sweat bee. On campus, it has been recorded on black medick, sumac, and goldenrod.
Status on campus: Uncommon
The bristle sweat bee is a fairly common species of metallic sweat bee. It is quite small in size, and has distinctive rows of tiny white hairs on the last few segments of the abdomen, sometimes visible to the naked eye. It often nests in disturbed soils in urban areas. On campus, it has been recorded on many plants, including mountain mint, fragrant sumac, hoary alyssum, and boneset.
Status on campus: Fairly Common
The very smooth sweat bee is a common species of metallic sweat bee. It has a wide range, from coast to coast. On campus, it has been found on a variety of plants including fragrant sumac, dandelion, buttonbush, sugar maple, and goldenrod.
Status on campus: Common
The lineated sweat bee is a common species of metallic sweat bee. It has two generations per year, with some nests in spring being established together by multiple females. They may have a preference for nesting in at least somewhat sandy soils. They are the most common Dialictus on campus alongside the nightmare sweat bee (L. ephialtum). They have been found most frequently on fragrant sumac, but have also been recorded on northern bush-honeysuckle, hawthorn, hydrangea, oxeye daisy, and many others.
Status on campus: Common
The black-and-green metallic sweat bee is an uncommon species, and is the largest metallic sweat bee in the eastern United States. Along with its size, it is also distinctive in having no patches or bands of hair on the abdomen like almost all other metallic sweat bees do. On campus, it has been recorded from fragrant sumac and flowering raspberry.
Status on campus: Very Uncommon
The oblong sweat bee is a fairly common species of metallic sweat bee. It is typically blue with a black abdomen, a combination only a few other metallic sweat bees in the northeast have. This bee can often be found in large numbers in wetland and coastal habitats, though they are present elsewhere as well. It nests in rotting logs. On campus it has been recorded on black medick and fragrant sumac.
Status on campus: Very Uncommon
The obscure sweat bee is a fairly common species of metallic sweat bee. It ranges across the eastern United States. On campus, it has been recorded on sugar maple.
Status on campus: Very Uncommon
The stunning sweat bee is an uncommon species of metallic sweat bee. It ranges across the eastern United States. On campus, it has been recorded on dandelion and crabapple.
Status on campus: Very Uncommon
The plated sweat bee is an uncommon species of metallic sweat bee. It is parasitic on other metallic sweat bees, though its exact host(s) are not yet known. It is the most frequently encountered parasitic Dialictus. On campus, it has been found on lanceleaf coreopsis and goldenrod.
Status on campus: Very Uncommon
The Saskatchewan metallic sweat bee is an uncommon species strongly associated with forest habitats. It nests in rotting logs. On campus, it has been recorded on fragrant sumac.
Status on campus: Very Uncommon
The epauletted metallic sweat bee is a fairly common species of metallic sweat bee. It is one of a few species that have enlarged, pitted tegulae (wing caps), which may be visible in close photographs. On campus, it has been recorded on fleabane, fragrant sumac, and devil’s walkingstick.
Status on campus: Very Uncommon
Megachilidae
Anthidium – wool-carder bees
Wool-carder bees are conspicuous, active, fast-flying bees with a compact, robust build and bright contrasting colors. Females collect the hairs from plant leaves to help construct their nests, while the much larger males patrol territories and attack any interlopers. Most are generalists, though there are some specialists. The greatest diversity is in the western United States, and there are no native wool-carder bees in the northeast – both species that occur here are introduced from Europe.
European wool-carder bees are a frequent and unmistakable sight in the garden. Males are large and boldly marked with black and yellow, flying circuits around patches of flowers – particularly those in the mint family, where females like to forage. The males have sharp spines on the tip of the abdomen which they use against perceived competitors. Females often collect plant hairs from garden ornamentals like lamb’s ear and dusty miller; these bees can be found in non-native garden settings. They have only been seen once on campus.
Status on campus: Very Uncommon
Oblong wool-carders are somewhat smaller than European wool-carders but are otherwise fairly similar in appearance. They are strongly associated with the non-native low-growing flower bird’s foot trefoil, which is common along sidewalks, in lawns, and waste areas. They are abundant on campus, though easy to miss as they forage at ground level.
Status on campus: Common
Chelostoma – scissor bees
Scissor bees are small, black, elongate bees that nest in pre-existing cavities. All are believed to be pollen specialists. They are easily overlooked or mistaken for wasps or ants given their slender profile and minute size. Scissor bees are fairly diverse in the western United States, but only three species occur in the northeast, two of which are non-native.
Mock-orange scissor bees are inconspicuous black bees that are pollen specialists on mock-orange trees (Philadelphus). They are the only native scissor bee in the state. There are no native mock-oranges in the northeast, thus these bees visit ornamental or escaped cultivated mock-orange. This species has only been seen once on campus, a male on buttercup. While the only planted mock-orange on campus is too small to flower, there is mock-orange elsewhere in the general area.
Status on campus: Rare
Coelioxys – cuckoo leafcutter bees
Cuckoo leafcutter bees are nest parasites, mainly of their cousins the leafcutter bees (Megachile). Females have sharply tapered abdomens, the tip of which is used to puncture the nest cells of their host to lay an egg inside. Males have several ‘teeth’ at the end of their abdomen. Cuckoo leafcutter bees are among the more frequently encountered cuckoo bees, though they are never abundant like nomad bees can be.
Modest cuckoo leafcutter bees are a rather small species of cuckoo leafcutter that are believed to parasitize patchwork leafcutter bees (Megachile centuncularis) and bellflower resin bees (Megachile campanulae). The former is known from campus, thus this is likely its host here. It has been seen once, on swamp vervain.
Status on campus: Rare
Eight-toothed cuckoo leafcutter bees are likely the most common cuckoo leafcutter in the northeast. They have been reported to parasitize several species of leafcutter bee, including species known from campus such as alfalfa leafcutters (Megachile rotundata), patchwork leafcutters (M. centuncularis), and Texas leafcutters (M. texana). They have been recorded on campus visiting hemp dogbane and swamp vervain.
Status on campus: Uncommon
The red-footed cuckoo leafcutter bee is a fairly common species that parasitizes the broad-handed leafcutter bee (Megachile latimanus) and black-and-gray leafcutter bee (M. melanophaea). The former is its likely host on campus. It has been recorded on campus visiting lance-leaved coreopsis.
Status on campus: Very Uncommon
Heriades – armored-resin bees
Armored-resin bees are small, black bees that are generalist flower visitors and nest in pre-existing cavities, typically in wood where they use plant resin to help construct their nest. They have an elongate body, with the abdomen often held somewhat curled. Viewed up close, they are coarsely sculptured – that is, they are covered in dense, deep sensory pits, much more so than similar-looking bees like small-mason bees. There are three species in the northeast.
Carinate armored-resin bees are the most frequently encountered armored-resin bee species in the northeast. They are very small and black with white bands on the abdomen, as with the other species. They often nest in manmade vertical wooden structures like garden fences, posts, and boardwalks. On campus, they are usually seen on boneset, wild bergamot, hemp dogbane, flat-topped goldenrod, and mountain mint.
Status on campus: Fairly Common
Leavitt’s armored-resin bee is a very uncommon species in the northeast. It is a generalist flower visitor and little is known about its habitat preferences. Females look identical to other armored-resin bee species to the naked eye, though males have a uniquely shaped plate on the underside of the abdomen. This bee has only been found once on campus, on boneset.
Status on campus: Rare
Hoplitis – small-mason bees
Small-mason bees are small, black bees with white bands on the abdomen and green eyes. They are solitary nesters but different species nest in the ground, in stems, or other cavities. The majority of eastern species are generalist flower visitors, with more specialists occurring in the west, however the generalists still tend to prefer deep flowers as is the case for most members of the leafcutter bee family.
The hairy-fronted small-mason bee is a fairly common species. It looks similar to other small-mason bees. On campus, it has been seen once, on foxglove beardtongue.
Status on campus: Very Uncommon
The produced small-mason bee is a fairly common species. Females look similar to other small-mason bees, though males are distinctive in having a large triangle-shaped protrusion on the underside of the abdomen. On campus, they have been seen on foxglove beardtongue, birds foot trefoil, wood mint, flowering raspberry, and swamp vervain among others.
Status on campus: Uncommon
Truncate small-mason bees are a somewhat uncommon species, slightly larger in size than other small-mason bees with long, curled hairs on the underside of the face to help gather pollen. On campus, they have been recorded on hairy beardtongue and low-growing weedy flowers.
Status on campus: Very Uncommon
Megachile – leafcutter bees
Leafcutter bees are common summer bees in the northeast, though are rarely abundant. They range from fairly small to very large in size, and have robust, blocky bodies. Like other members of this bee family, leafcutter bee females carry pollen on a dense brush of hairs on the underside of the abdomen, not on the legs. They get their name from their habit of using their large mandibles to cut semicircular pieces of leaves or flower petals from plants in order to help build their nest. Most leafcutters nest in pre-existing cavities, including many manmade structures, and all are solitary. The majority are generalist flower visitors, but some are specialists.
Patchwork leafcutter bees are a species of leafcutter bee that is widespread across North America and Europe; it is now believed that they may have been introduced into North America at some point in the past. They are similar in appearance to golden-tailed leafcutters. On campus, they have been recorded on black-eyed susan, lanceleaf coreopsis, and sweet william.
Status on campus: Uncommon
Frigid leafcutter bees are a fairly large species of leafcutter. They are known to nest in rotting logs. Males are one of a handful of species with ornamented front legs, being expanded, light in color, and with a dense brush of hair. Unlike others though, they have two bold dark stripes on the inside of the front femur. On campus, this species has been seen on birds foot trefoil and vetch.
Status on campus: Very Uncommon
Broad-handed leafcutter bees are a fairly large species of leafcutter. Unlike most other leafcutters, they nest in the soil. Males are distinctive in having ornamented front legs (expanded, light in color, with a brush of hair down the side) along with the body being covered in fuzzy yellow hair, giving them a ‘teddy bear’ look. On campus, they have been recorded on aster.
Status on campus: Very Uncommon
Pugnacious leafcutter bees are a distinctive species with massive mandibles and a large head. Males are one of a handful of species with ornamented front legs (expanded, light in color, with a brush of hair down the side). They are pollen specialists on plants in the aster family, especially coneflowers, coreopsis, and sunflowers. They nest in rotting logs and other types of cavities. On campus, they have been seen on black-eyed susan, lanceleaf coreopsis, and wild bergamot.
Status on campus: Fairly Common
Golden-tailed leafcutters are a common, widespread species of leafcutter that visits many different flowers. They nest in various types of cavities. On campus, they have been recorded on Canada goldenrod and goutweed.
Status on campus: Very Uncommon
Alfalfa leafcutter bees are a small-bodied, energetic leafcutter bee that are an economically important pollinator of alfalfa. They were accidentally introduced from Europe but have since become a heavily managed agricultural species, pollinating alfalfa several times better than honeybees. While they are widely distributed across North America they tend to occur near farmland and other disturbed areas. This bee is very abundant on campus, having been recorded on nearly 20 different flowers, particularly hemp dogbane, oxeye daisy, swamp vervain, mountain mint, and sneezeweed.
Status on campus: Common
Sculptured resin bees are very large, conspicuous leafcutters that are a fairly recent introduction from Asia. They are sometimes considered invasive due to their ability to compete with native carpenter bees for nest sites, as they nest in pre-existing wood cavities. Females can be an inch long and have brown hair on the thorax and a bare cylindrical abdomen, resembling carpenter bees but more elongate and with larger mandibles. They prefer to visit non-native plants. On campus, this bee has only been seen once but they are known from the general area.
Status on campus: Very Uncommon
Texas leafcutter bees are fairly common leafcutters with a grayish appearance (black body with gray and white hairs). They are soil-nesters and generalist flower visitors. On campus, they have been seen on swamp milkweed and buttonbush.
Status on campus: Uncommon
Osmia – mason bees
Mason bees are fairly small, chunky metallic blue bees active in spring and early summer. Like other members of the leafcutter bee family, they carry pollen on a dense brush of hair beneath the abdomen, instead of on the legs. Some species of mason bee are commercially managed for pollination of apple orchards and other spring fruit crops, as they are much more efficient than honeybees. Mason bees get their name from the tendency of many species to use mud to shape the interior of their nests. Different species will nest in a variety of cavities, with a few even using snail shells. Most are generalists but there are many pollen specialists.
Bufflehead mason bees are one of the most recognizable mason bees in the northeast. They resemble small bumblebees, but look closely for the metallic sheen beneath their fuzzy hair and a head much wider than a bumblebee. They also carry pollen underneath the abdomen instead of in a bumblebee’s pollen basket. They are generalist flower visitors, though they prefer deep flowers, and are pollinators of many spring woodland ephemerals. Later in the spring they frequent penstemons. On campus, they have been seen on foxglove beardtongue.
Status on campus: Uncommon
Horn-faced mason bees are common spring bees in disturbed landscapes. They were intentionally introduced from Asia to enhance crop pollination and have spread to inhabit much of the eastern United States. They frequently make use of man-made bee hotels. Unlike native mason bees, horn-faced mason bees are covered in fuzzy tan hair, and have two ‘horns’ on the face used to help them gather mud for nesting. They are very abundant on campus in spring, particularly on willows and crabapple.
Status on campus: Common
Georgia mason bees are an uncommon species of mason bee that is recognizable by the bright orange scopae (brush of hairs beneath the abdomen) and prominent protruding knobs on the front of the mandibles, used to help gather nesting material. They prefer to visit plants in the aster family. On campus, they have been seen on lanceleaf coreopsis and oxeye daisy.
Status on campus: Uncommon
Blue orchard bees are one of the few agriculturally managed native bees, being widely used for pollination of apple orchards and other spring fruit crops. They have a preference for flowers in the rose family, which includes crops like apples, raspberries, and cherries. They are also distinctive in appearance among mason bees, being fairly large in size and having patches of dark hair on their body. On campus, they have been recorded on hawthorn and crabapple.
Status on campus: Very Uncommon
Dwarf mason bees are a common spring mason bee that is quite small in size. They are very similar in appearance to several other mason bee species, being metallic blue with white scopae (brush of hair beneath abdomen for collecting pollen). They are typically associated with forest habitats, and nest in plant stems. On campus, they have been recorded on white clover.
Status on campus: Very Uncommon
Taurus mason bees are an introduced species from Asia, and are similar in appearance to horn-faced mason bees. They are covered in fuzzy hair that tends to be somewhat more rusty in color than the tan hair of horn-faced mason bees. While both species often occur together, taurus mason bees are rarely abundant. On campus, they have been seen on willow.
Status on campus: Very Uncommon
Pseudoanthidium – small-woolcarder bees
Small-woolcarders are robust, compact bees that are small in size and exhibit the behavior of collecting plant hairs for nest construction shared with wool-carder bees (Anthidium). They nest in pre-existing cavities and many are specialists on plants in the aster family. Only one species occurs in North America, the European small-woolcarder, which is introduced.
The European small-woolcarder is a small, boldly marked bee that was introduced from Europe very recently, first detected in 2008. It has quickly spread across much of the northeast, mid-Atlantic, and Midwest, and has been detected separately in the Pacific northwest. It nests in wood cavities and plant stems, and primarily visits plants in the aster family. It can be distinguished from other small-bodied wool-carder and resin bees by the very small size, pale oval spots on the abdomen (rather than yellow bars), and blue eyes. It is fairly abundant on campus, though easy to miss, and has primarily been seen on oxeye daisy and threadleaf coreopsis.
Status on campus: Fairly Common
Stelis – dark bees
Dark bees are nest parasites of other bees in the leafcutter bee family. Many parasitize leafcutters (Megachile), while others go after small-mason bees (Hoplitis), armored-resin bees (Heriades), or resin-leafcutters (Trachusa). In the northeast, dark bees are black with light-colored markings, though in the west some are metallic. They often closely resemble their hosts, if not for these small light markings. Dark bees are generally uncommon and not often encountered.
Compressed dark bees are a very uncommon species of dark bee that parasitizes the carinate armored-resin bee (Heriades carinata). They are smaller and more slender than other dark bees, giving them a very similar appearance to their host, though the small light-colored markings on their abdomen set them apart. On campus, they have been recorded on creeping thistle and low-growing weedy flowers.
Status on campus: Very Uncommon
Spot-sided dark bees are among the more frequently encountered dark bees. They are nest parasites of small-mason bees (Hoplitis). They are quite small but bulky in build, like a mason bee shrunken down in size. On campus, this species has been seen once, on hemp dogbane.
Status on campus: Rare
Louisiana painted-dark bees are likely the most commonly seen dark bee in garden settings, due in part to its bold patterning making them more conspicuous than other dark bees. They are small and elongate, with smoky wings and bright yellow markings resembling some other bees in the leafcutter bee family like northern rotund-resin bees (Anthidiellum notatum) or sunflower burrowing-resin bees (Paranthidium jugatorium). This species parasitizes bellflower resin bees (Megachile campanulae), which have not yet been found on campus. They have been observed on swamp vervain.
Status on campus: Very Uncommon