ID GUIDE TO WILD BEES - NEW YORK

ANDRENA MINING BEES

ANDRENA MINING BEES 
(Genus Andrena)

Andrena mining bees belong to Andrenidae, one of the six principal families of bees found in the United States.  The genus Andrena is one of the largest bee genera in the world and the most diverse in North America, comprising 400 species on this continent and nearly 1500 worldwide. 

In the western hemisphere, Andrena bees appear only in North America.  They flourish in temperate areas, but also seem immune to cold:  they are found even in northern Canada, and they emerge in New York when spring temperatures are still chilly and the last snows linger on the ground.  Andrenas may surface many days before the plants on which they forage blossom.

 

In early spring, Andrena bees can be seen sunning themselves in the park, basking on rocks or sunlit leaf-littered banks.  According to Wilson & Carril's The Bees in Your Backyard, Andrenas engage in this behavior in order to raise their body temperatures -- which must reach at least 50 degrees before the bees can fly.   

 

Andrenas are commonly referred to as "mining bees," because they construct underground nests. In mid-March, if you scour the ground along park trails, you may spy the holes of Andrena nests, usually no more than half an inch wide, partially buried among leaf litter.  (A nest is shown in the photo strip at right.)  Andrenas are solitary nesters -- they do not form colonies like honey bees and do not swarm in attack.  Nevertheless, Andrena mining bees nest close by one another, sometimes forming collective populations numbering in the tens of thousands.  In such “bee cities,” each female usually builds her own nest and individually supplies it with food. 

 

Throughout North America, Andrena bees are essential pollinators of a vast range of native wildflowers and garden plants. In spring, Andrena bees can be found pollinating the park's woodland bulbs, wild berries and flowering trees and shrubs; gathering nectar from tree peonies in the park's Visitors Office garden; and visiting blossoming fruit trees, blueberries, roses and herbs in the orchards and gardens of Stone Barns Center for Food & Agriculture.  Spring-emerging Andrenas tend to disappear from the park and Stone Barns by early summer.  Thereafter, other Andrena species appear that specialize in summer and fall wildflowers.

 

These bees are non-aggressive and their stingers too fragile to sting humans; if approached, they zoom quickly away.

 

Identification Information:  Most Andrena bees are small to medium-sized (honey-bee-sized or smaller).  Andrenas often look "furry," with notably hairy thoraxes, faces and legs.  The hairs covering the bees may be black, grayish, pale, brown or rust-colored.   The bees' abdomens appear dark and are sometimes striped with pale bands.  

All Andrena species share a distinctive facial characteristic:  Andrenas have two "sutures" (dark lines) under each antenna; facial depressions called foveae rest alongside the sutures.  As shown at right, on female  bees, the foveae are covered with hairs that are sometimes described as looking  like "sideways eyebrows".  Male bees may have shaggy patches of hair covering their faces.

 

A second distinguishing Andrena trait is that the female bees look as if they carry pollen under their "armpits".  This is because they tuck pollen onto collecting hairs called scopae located on their upper hind legs.  Because Andrenas tend to be hairy, pollen often clings to their thoraxes inadvertently as well. This occurs as the bee buries itself in a blossom: electrostatically charged pollen clings to the oppositely charged hairs of the bee.

​This page shows a sampling of varieties of Andrena bees: 
20 species representing 14 Andrena subgenera (subgenuses) have been documented at Rockefeller State Park Preserve and Stone Barns Center for Food and Agriculture.  According to entomologist John S. Ascher, more than 50 Andrena species occupy the New York area in which Rockefeller Park Preserve is located.

 

Taxonomy of Andrena Mining Bees:
 

Order:   Hymenoptera

Superfamily:   Apoidea (Wasps and Bees)
Family:    Andrenidae (Mining Bees)

Subfamily:  Andreninae
Genus:   Andrena


Subgenera (subgenuses) shown on this page:
Andrena,
Callandrena sensu lato, Cnemidandrena,
Conandrena, Holandrena, Larandrena, Leucandrena, Melandrena, Plastandrena, Ptilandrena, Scrapteropsis, Simandrena, Taeniandrena, Trachandrena

​Andrena species shown on this page:
 

Alleghany Mining Bee (A. alleghaniensis)
Bradley's Mining Bee (A. bradleyi)

Carlin's Mining Bee (A. carlini)
Cloudy-winged Mining Bee (A. nubecula)
Cresson's Mining Bee (A. cressonii)
Confederate Mining Bee (A. confederata)

Dunning's Mining Bee (A. dunningi)
Forbes' Mining Bee 
(A. forbesii)

Hairy-banded Mining Bee (A. hirticincta)
Hawthorn Mining Bee (A. crataegi)
Long-lipped Mining Bee (A. barbilabris)
Milwaukee Mining Bee (A. milwaukeensis)

Miserable Mining Bee (A. miserabilis)
Nason's Mining Bee (A. nasonii)

Neighborly Mining Bee (A. vicina)
Placid Andrena /Simple Andrena (A. placata/simplex)
Plum Andrena (A. pruni)
Rugose Andrena
 (A. rugosa)
Spring Beauty Mining Bee (A. erigeniae)
Wilkes Mining Bee 
(A. wilkella)

A male Andrena bee gathering pollen in mid-March, when snow still lies on the ground.

Some male Andrena bees have distinctive shaggy patches of white hair on their faces.

Andrena bees have facial structures called foveae.  On female Andrenas, pale hairs grow from the foveae,  along the inside margins of the eyes, forming patches that  are sometimes described as looking like  "sideways eyebrows".

All photos (c) 2014 - 2016 Sharp-Eatman Nature Photography

Andrenas of Early Spring

Milwaukee Mining Bee

Andrena milwaukeensis
(Andrena Subgenus Andrena)
1/3" (males)  to 2/5"  (females)  (medium-sized)

The genus Andrena is divided into thirty or more North American subgenera (subgenuses), a sampling of which is provided on this guide page.  One of these is the repetitively named subgenus Andrena.  Bees of this subgenus are found throughout the northern hemisphere, in places as far flung as Saskatechewan, Alaska, Japan and Mexico.

 

In flight, the brightly-colored Milwaukee mining bee looks like a fox-colored blur zipping through the air.   This enchanting  Andrena was discovered in 1903 by the Milwaukee entomologist S. Graenicher, who named it after his home town.  In recent years, Milwaukee mining bees have been documented through bugguide.net in others area with harsh winters  -- Minnesota, North Dakota, Saskatchewan, Alberta and Labrador, for example.  The bees, however, are also found in warmer states in both the western and eastern U.S.  As noted below,  Andrena milwaukeensis varies in appearance according to location. 

 

Milwaukee mining bees are woodland bees.  Like other Andrenas shown on this page, Milwaukee mining bees nest in the ground.  Milwaukee mining bees appear in the park in late April, sunning themselves on rocks amid leaf-litter on the forest floor.  Males emerge before females. These bees seem particularly shy, scuttling quickly away to hide under debris or in their holes when approached.

 

The Discover Life Database describes Milwaukee mining bees as pollinators of blueberries, cranberries, apricots, pears and apples -- and also of a range of native trees and shrubs including dogwood, viburnum, chokecherry and wild cherry, among others.  S. Graenicher noted the bees feeding in 1903-1904 in Wisconsin on claytonia, snowberry, bush honeysuckle, native bittersweet, spirea and currants.  Canadian contributors to bugguide.net have photographed this species feeding on squill, buffalo berries and violets.


Identification information:  Andrena milwaukeensis is a striking bee, intensely brightly colored, with rust-orange hairs that cover its thorax and part of its abdomen.  These hairs are aptly described as looking like a “fox-fur coat”.   In New York, the female bee’s rust-colored hairs extend to the second segment of the abdomen; the remainder is deep black. In middle and western Canada and the United States, the orange hairs may extend as far as the sixth abdominal segment.  Female bees in both locations have shaggy jet-black hair on  their legs.  The black scopal (pollen-gathering) hairs on the bottom segments of the bees' hind legs are a distinguishing trait of this species.

According to Charles D. Michener’s The Bees of The World, mining bees of the subgenus Andrena have a clypeus that is flattened and broad, a characteristic of the female Milwaukee mining bee shown  here. (A bee's clypeus is located at the bottom of its face, above its jaws.)   The hair on the female bee’s face is completely  black, obscuring the facial fovaea or "sideways eyebrows" typical of all other female Andrenas shown on this guide page.  As a result, these bees may not appear Andrena-like on first glance.  Females also have black eyes and antennae, with just a few rust-colored tufts of hair above the antennae. As shown in the photographs at right, female Milwaukee mining bees have sizable mandibles and distinctive wing veins. 

The mandibles of male Milwaukee mining bees are even longer, and sickle-shaped. Males are generally somewhat smaller than females.  They too have bright fox-colored hair on their thoraxes, but have less reddish hair on their abdomens than do females.  Males also have pale hairs on the inner sides of their bottom leg segments. 

 

Milwaukee mining bees are a more intensely bright orange than any of the other Andrena bees shown on this page.  The closest in color, A. barbilabris and A. dunningi, shown below, can be distinguished because the bees' rust-red hair does not extend past the thorax.  A. barbilabris also has pale interrupted banding on its abdomen.  Andrena milwaukeensis is very similar in appearance to the European species shown as A. fulva.

Female Andrena milwaukeensis bees have bright fox-colored hair on their thoraxes and
on some abdominal segments.

All photos (c) 2014 - 2016 Sharp-Eatman Nature Photography

Miserable Mining Bee

Andrena miserabilis
(Andrena Subgenus Larandrena)

1/4" - 1/3"  (small)

Andrena miserabilis is known as the "miserable mining bee" for no readily explained reason – the mystery of this bee’s name remains deeply buried in the catacombs of bee-naming history. The bee seems no more miserable than other members of its genus – except perhaps for the fact that it emerges very early in the spring, when the weather is still chilly -- as early as mid-March in our area.  Miserable mining bees can be found throughout wooded areas of Rockefeller State Park Preserve, feeding on the blossoms of the first trees and shrubs to bloom in spring -- willows, red maples, spicebush and dogwood.  In April, these bees appear in the Rockwood Hall section of Rockefeller State Park Preserve, foraging on dandelions and March-blooming tulip magnolia trees. 

 

Miserable mining bees are relatively small for Andrenas:  males are between 1/5" and 1/4", and females slightly larger, up to 1/3”.  The bees’ small size makes them especially vulnerable to predators such as the jumping spider (shown at right), which hides in large flowers such as magnolias and snatches miserable mining bees as they alight on the blossoms to gather nectar and pollen. Like Andrena miserabilis, jumping spiders emerge in the park in mid-March and, in our experience, seem to materialize wherever the small bees are feeding.  


Miserable mining bees inhabit woodland habitats.  They are pollinators of a wide range of native spring-flowering trees and shrubs.  In addition to those plants noted above, Andrena miserabilis bees pollinate sumac, American holly, hawthorn, common lilac, chokecherry and wild cherry.  These bees also visit ornamental plants such as boxwood and forsythia. Miserable mining bees are significant pollinators of a variety of fruit crops, including peaches, apples, strawberries, blackberries, raspberries  and gooseberries. 

 

True to their genus Andrena, miserable mining bees are solitary and nest in the ground.  They are non-aggressive and do no measurable harm to areas inhabited by people.  The bees' nests sometimes appear in small groups of a dozen or fewer and are limited to around eleven inches in depth.  In addition to being targets of  jumping spiders, these tiny bees are preyed on by Sphecodes cuckoo bees and ants, which infiltrate Andrena miserabilis nests.

Identification Information:   Miserable mining bees are slender, graceful bees with dark, wide heads and long dark bodies. Their abdomens are blackish brown and smooth and encircled with bands of pale hairs.  Male bees have pale yellow masks on the lower part of the face (known as the clypeus), dotted with two black markings that look like false nostrils.  Some males also sport long, curved jaws that meet in the middle, like scissors made of scimitars.  Males use these jaws to fight one another.

Female miserable mining bees lack the yellow face mask characteristic of males.  Females bees can be recognized by the traits highlighted in the photo strip at right:  (1) They have broad facial foveae that extend fairly high up on their faces; (2) the bees' clypeuses are shiny and black; and (3) the back of the female bee's thorax is rimmed with a tuft of reddish hairs. 

 

The miserable mining bee is the sole North American member of its subgenus, Larandrena.  According to Charles D. Michener, Andrena miserabilis can be distinguished from very similar mining bees of the subgenus Parandrena by a subtle difference in wing venation:  miserable mining bees have three submarginal cells in their wings (shown in the photo strip at right), while Parandrena have only two.

 

These bees are identifiable in part by when they appear.  They are active in the park only in early spring.  The bees shown here appeared in the park in March, 2016; in 2015 and 2017, these bees visited the park in April.

A miserable mining bee being carted away by a Jumping Spider

A female Andrena miserabilis:  note the wide facial foveae or "sideways eyebrows".

All photos (c) 2014 - 2017 Sharp-Eatman Nature Photography

Spring Beauty Mining Bee
Andrena erigeniae
(Andrena Subgenus Ptilandrena)

medium-small - 3/10”

Andrena erigeniae is an important specialist pollinator that visits the flowers of the native spring bulb Claytonia virginica, known locally as spring beauty.  A member of the purslane family, spring beauty is an exquisite woodland flower, less than an inch wide, with five petals shaded a subtle pink and streaked with veins of magenta.  Its petals are set in a delicately-colored yellow-green cup from which five pink stamens, dusted with pink pollen, protrude.  The plant is low-growing, ranging from 4 to 12 inches high, and tends to cluster in groups, carpeting the forest floor in pale pink before spring trees have fully leafed out. We owe the proliferation of this beautiful native wildflower to the Andrena erigeniae bee.

 

Spring beauty flowers emerge in our area between mid-April and early May, during the same period in which cherry and dogwood trees begin to bloom.  Each spring beauty plant bears multiple flowers; each flower blooms for three days, but its stamens are active only for a single day. This means that  Andrena erigeniae bees, dependant on these spring bulbs for both pollen and nectar, must time their pollinating activity carefully. Prominent entomolgist Wallace E. Laberge wrote that he had observed pollinating Andrena erigeniae bees flying even during spring rain showers, in order to avail themselves of the bloom season for their principal food source.  

 

The flight period for spring beauty mining bees is 50 days, beginning 10 days after spring beauty starts blooming and ending 10 days before its bloom period ends. In our area, the bees tend to emerge fairly late in the afternoon, and despite Laberge's claim, you are most likely to spot these Andrena pollinating flowers on sunny days.  This may in part be because claytonia flowers close on rainy and cloudy days; they also open fairly late in the morning, and close again around early evening.

 

According to Laberge, spring beauty mining bees frequent woodland habitats, nesting along well-drained marginal areas situated where spring beauty grows. The bees hide their nests under light leaf litter, to protect themselves from moisture and predators. Andrena erigeniae build solitary nests, but are considered “gregarious,” because they tend to group their nests nearby one another. The bees mate near their nests, and soon afterward the females disappear into the ground to lay eggs and begin provisioning for their young. Spring Beauty Andrenas are somewhat unusual because their larvae pupate during late summer and become adults by fall. They then overwinter as adults.

 

The Latin name of spring beauty mining bees is a misnomer – erigeniae refers to the plant Erigenia bulbosa, an early-emerging bulb known as Harbinger of Spring or more commonly, Salt and Pepper, which was originally misidentified as the bees' principal host plant. Wallace E. Laberge later noted that female spring beauty mining bees were restricted to Claytonia virginica alone as a pollen source. The Discover Life database now records apples and blueberries as occasional alternate host plants for this Andrena species.

 

Identification information:  Andrena erigeniae bees belong to the Andrena subgenus Ptilandrena. They are fairly /small bees with black bodies and long pale hairs on their heads, thoraxes and legs. Some Andrena erigeniae have a reddish cast --  their wings are glassy with reddish-brown or dark brown veins. The bees’ legs are dark, sometimes with brick-red spurs, and their abdominal segments are reddish along the base.

 

Female Andrena erigeniae have distinctive narrow facial foveae (hair-covered grooves that rim the inner edges of the bee's compound eyes, which look a little like sideways eyebrows).  On females, the foveae can have a pale gold or brownish tinge.

 

A telling characteristic of female spring beauty Andrenas is the distinctly pink color of the pollen balls the bees carry – as noted, the pollen of spring beauty is pink. If you see an Andrena alighting on spring beauty but carrying bright yellow pollen balls, this may be a sign that it is a different generalist species – not Andrena erigeniae -- that is just visiting the spring bulb after gathering pollen from a different flower. (Nevertheless, Laberge notes that sometimes the spring beauty’s pink pollen balls fade to pale yellow if exposed for long periods.)  A number of other varieties of bees also nectar on claytonia -- among them, nomad bees, mason bees and other species of Andrena.  Very small Empis dance flies and fire-colored beetles also sip nectar from spring beauty.

 

 Male  spring beauty  mining bees are smaller than females.  To the naked eye, male bees appear black and slender, with disproprtionately large heads.  One other minute identifying trait, barely visible to a photographer's macro lens, is noted by bugguide.net:  on males, the hindmost tip of the  underside of bee's abdomen is split in two.

Spring Beauty in bloom

All photos (c) 2014 - 2017 Sharp-Eatman Nature Photography

A female spring beauty mining bee

A male spring beauty mining bee

Face of a male spring beauty mining bee

Nason's Mining Bee

Andrena nasonii
(Andrena Subgenus Simandrena)

1/5” -1/3” (small)

The spring beauty mining bees shown in the guide entry above are not the only Andrena that feed on claytonia. Nason’s mining bee, an all-purpose generalist pollinator, also visits this woodland bulb.  Andrena nasonii is a versatile bee that surfaces in  the park in April and May, foraging on a breathtakingly diverse spectrum of spring-blooming plants.

 

The Discover Life database has documented Nason’s mining bees feeding on a list of plants that is comicaly long.  It includes:  alfalfa, American holly, apples, beach plum, birdsfoot trefoil, blackberry, blueberry, boxwood, buttercups, carnations, chickweed, chrysanthemums, cinquefoil, claytonia, coltsfoot, common starwort, cranesbill, crinkleroot, cutleaf toothwort, dandelion, dewberry, dogwood, flatweed, fleabane, forget-me-nots, hawkweed, honeysuckle, leatherleaf, lilac, melons, mountain laurel, peppergrass, pepperweed, pyracantha, red maple, roses, serviceberry, sour cherry, speedwell, thistle, spiraea, trout lily, viburnum, wild geranium, wild strawberry, willow, winter rocket, yarrow, yellow sweet clover, and zizia.

 

Andrena nasonii’s singular flexibility in foraging for food highlights the importance of generalist pollinators within our ecosystem. These bees’ survival helps guarantee the continued existence of an enormous range of flora even when pollinators that specialize in particular plants enter periods of scarcity.

 

Identification Information:  Andrena nasonii are fairly small bees.  Males are around one fourth inch long and females barely top one third inch. Nason’s mining bees are eye-catching, however, because they have three bold, well-defined white bands on their dark abdomens.  

 

Viewed minutely, these bees have three other distinctive traits as well, as shown in the photo strip at right.  (1)  An Andrena nasonii's abdominal segments fit into one other like sculpted plates. (A small percentage of Nason's  mining bees lack this trait.)  (2)  the top segment of the bee's abdomen has no stripe, and on the second segment, the stripe is broken at the top.  (3)  On the bee's hind leg, the tibia (the second leg segment down)  is twice as wide as the basitarsus (the segment below this).  

 

Generally, viewed with the naked eye, Nason's mining bees have dark heads and bodies covered with fine pale hairs. Female bees have especially wide patches of hair (fovaea) on their faces, and males have especially long antennae.

A female Nason's mining bee on a spring beauty blossom.

All photos (c) 2014 - 2016 Sharp-Eatman Nature Photography

Cresson's Mining Bee

Andrena cressoni cressoni
(Andrena Subgenus Holandrena)
1/3"  to 2/5"  (medium-sized)

Andrena cressonii belongs to the mining bee subgenus Holandrena.  Bees of this subgenus tend to have broad faces and bands of pale hair on their abdomens; male Holandrena often have yellow masks.  Holandrena are holartic – that is, they occur in habitats throughout continents of the northern hemisphere, as far-flung as Canada and Japan.  In North America, Holandrena live as far north as Nova Scotia and as far south as Zacatecas, Mexico, and  are found in both the western and eastern United States.  There are eighteen species of Holandrena worldwide; four live in North America. 

Only one Holandrena species is found in the northeastern United States --  Cresson’s Andrena. This mining bee is an important broad generalist pollinator of an astonishing variety of our native woodland trees and shrubs, among them dogwood, oak, wild cherry, magnolia, willow, American holly, New Jersey tea, deerberry, chokecherry, serviceberry, hawthorn and ninebark.  Cresson’s Andrena also pollinates meadow flowers such as buttercups, anemone and wild roses.  This mining bee is, in addition, a useful pollinator of a spectrum of commercial crops, including apples, pears, gooseberries, blueberries, strawberries and caneberries.  Cresson’s  Andrenas also can be spotted foraging on common weeds such as dandelions and garlic mustard.

Cresson’s mining bees appear in early May in the park.  Males remain visible through the last week of May; they have a lifespan of about four weeks.  According to entomologist Eugene R. Miliczky, females live nearly twice as long, around eight weeks, and may continue pollinating into early summer. In early May, males can be seen patrolling vegetation in search of females.  The bees thereafter mate out in the open on their host plants.  Females are industrious pollen-gatherers.  Miliczsky recorded them making repeated trips from their nests, resting for barely half a minute between trips.

Cressons’ mining bee nests tend to be well-concealed under leaf-liter and their eggs fairly deeply buried.  One nest observed by Miliczky proceeded horizontally for a few centimeters, and then plunged downward vertically to a depth of 20 cm (about 7 inches), before levelling off again to a chamber where the eggs were stored; these chambers were also plugged with soil.  Cressons’ mining bee larvae hatch from their eggs in September and then overwinter.

ID information:  The male Cresson’s Andrena shown here is slightly longer than 1/3 inch.  The bee has a black head, body and legs, and an abdomen banded by weakly-defined white hairs on its second through fourth segments T-1, T-2 and T-3). The male Cresson’s Andrena is easy to identify, because of the striking yellow mask on its face.  The mask is distinctive, because its yellow does not simply cover the bee’s clypeus (the part right above the jaws); it extends outward, rimming the bottom portions of the bee's compound eyes.  The male Cresson’s Andrena also has an additional distinguishing trait, somewhat difficult to perceive with the naked eye – the end of the bee’s abdomen has a long, thin, tip.

Male Cresson’s Andrenas can be confused with male miserable mining bees (shown higher up on those page), because both have yellow masks, but note the following differences:  (1) on male miserable mining bees, the yellow mask tends to be confined to the clypeus only; (2) the face of the male Cresson’s Andrena is much wider;  and (3) male miserable mining bees usually have long, scimitar-like jaws, while the jaws of male Cresson's mining bees are fairly short.  These traits are shown  in the photo strip at right.   

Female Cresson’s mining bees are less distinctive and more difficult to identify with the naked eye.  They are medium-sized bees, around 1/3 to 2/5 inches long, with dark bodies and abdomens.  Their legs are black to dark reddish-brown, and the second, third and fourth segments of their abdomens (T-2, T-3 and T-4)  are banded on top by well-defined stripes of pale hair.  (T-5 and T-6 may have brown hairs.)  On the subspecies found in our area,  Andrena cressoni cressoni, the pale abdominal bands may be interrupted on top on the second and third segments. The female is also distinguished by a short labral process (the face part just above the bee’s jaws).  Because male Cresson’s Andrenas are fairly easy to recognize, females are most easily identified if you simply catch them mating with their male counterparts. 

Subspecies of Andrena cressoni:  Entomologist LaBerge identified three subspecies of Cresson’s Andrenas in America.  The subspecies shown here, Andrena cressonii cressonii, is found over an extensive range in North America – from Canada south to the Gulf Coast, and from the Altantic coast westward into Texas, Kansas, Nebraska, Wyoming and Montana.  A second overlapping subspecies, Andrena cressonii kansensis, is found farther west in the prairie states, and has bright orange-red coloration on its legs (on the femurs and on the middle and hind tarsi, in both males and females).  The band of white hairs on the the third abdominal segment (T-3) of Andrena cressonii kansensis is also complete, not interrupted, as on Andrena cressonii cressonii.  A third subspecies, Andrena cressonii infasciata, is found on the west coast:  it is slightly larger than our eastern variety and its abdominal bands tend to be less well-defined and broadly interrupted. Occasionally, this third subsepecies has bright orange-red leg segments like A. cressonii kansensis.

A male Cresson's mining bee

A male Cresson's Mining Bee

All photos (c) 2014 - 2017 Sharp-Eatman Nature Photography

Spring Andrenas (Melandrena)

Neighborly Mining Bee

Andrena vicina
(Andrena Subgenus Melndrena)
2/5" to 1/2"  (medium-sized)

Another example of  the Andrena subgenus Melandrena, neighborly mining bees are broad generalist pollinators. They are perhaps best known in our area for being ardent pollinators of blueberries. These bees also visit a prodigious array of fruits and garden plants, including boxwood, rhododendron, apples, melons and cranberries.  Their common name is said to allude to the  bees' predilection for nesting in gardens and orchards close to human habitations.  An alternate theory is that they were christened "neighborly" because they like to build their nests  close by one another, often in large groups.

Andrena vicina are spring bees.  They emerge in the park in mid-April and disappear by May. Like other Andrenas, they are solitary and nest in the ground. Their nests are easiest to find in leaf-littered areas where pastureland borders woodlands in the Rockwood Hall section of the park.

Neighborly mining bees visit a remarkably diverse array of native woodland trees, shrubs and meadow plants.  They pollinate, among others, redbud, dogwood, hawthorn, American holly, chokecherry, ninebark, deerberry, serviceberry, white colicroot, and swamp milkweed.  When native plants are not available, these hardy bees forage among common weeds such as thistles, dandelions, field mustard, red and white clover, winter cress -- and even the toxic invasive leafy spurge.

Andrena vicina are sometimes preyed on by stylops, a twisted-wing insect that lodges in the abdomens of neighborly mining bees.  (One is shown in the photostrip at right.)  Female stylops are wingless and enter their hosts as larvae, feeding on the bees.  They emerge part-way from the bees' abdomens and emit a pheramone that attracts winged male stylops.  The offspring produced fall from the host to flowers or the ground.   Neighborly mining bees are also preyed on by the red-horned nomad bee Nomada imbricata.

Identification Information:  Female neighborly Andrenas are typical of their subgenus Melandrena.  They are relatively large (typically slightly bigger than honey bees), and have black heads and abdomens and light-brown thorax hairs.  They also have black scopal hairs on their back legs.  These traits all make female Andrena vicina easily confusable with female Andrena carlini bees, shown directly above on this guide page.  These can be distinguished from one another by the fact that female neighborly mining bees have pale hairs on the undersides of their thoraxes while A. carlini females have dark hairs.  Neighborly mining bees also have white hairs on the top segments of their front middle legs (femurs),  as shown in the photograph above right.

Male neighborly Andrenas have dark abdomens and pale hair on their faces and thoraxes.  They are difficult to distinguish with the naked eye from other males of the subgenus Andrena melandrena.  The simplest way to identify males is to note mating behavior and observe which female bees males pair up with.  Female Andrena melandrena are more distinctive and easier to tell from one another.

A female neighborly mining bee

A male neighborly mining bee

Plum Andrena

Andrena pruni
(Andrena Subgenus Melandrena)
1/3" to 2/5"  (medium-sized)

This bee is described by the Discover Life Database as “relatively scarce”. The bee shown at right was found in Rockefeller State Park Preserve in April, exploring crevices in the earth in the particularly beautiful glade at the foot of Eagle Hill Trail. 

 

The name pruni means "plum" in Latin and refers to the plant genus Prunus, which contains plums and cherries.  Plum Andrenas are documented polllinators of these stone fruits, and of apples, pears and berries as well. Plum Andrenas are also pollinators of the spring-flowering woodland plants known as spring beauty, bloodroot, Jacob’s ladder and bellwort.  The bees additionally pollinate native trees and shrubs such as wild plum, wild cherry, buffalo berry, ninebark, hawthorn, viburnum and willow.

Plum Andrenas are woodland bees. Like the other Andrena (Melandrena) bees shown on this page, plum Andrenas construct solitary underground nests.  The nests are usually carefully hidden under leaf-litter. 

 

Identification Information:  Plum Andrenas share many similarities with the other mining bees of the subgenus Melandrena shown on this guide page. Like them,  the plum Andrena is relatively large and has a black head and abdomen and a furry thorax.  Nevertheless, the plum Andrena can be differentiated easily from Carlin’s mining bee and the neighborly mining bee shown above, because the plum Andrena has ostentatious blond hairs on all of its legs – the other two mining bees have black or mostly black hair on their hind legs. The plum Andrena most closely resembles Dunning’s mining bee, shown below, but the examples we’ve seen of Andrena pruni have yellowish-brown or blond hairs rather than the rust-red hairs characteristic of Dunning’s mining bee.

 

In addition, according to the Discover Life Database, the plum Andrena has the distinctive trait of very narrow facial foveae (the “sideways eyebrows" characteristic of female Andrenas). Male plum Andrenas also have a trait that aids greatly in their identification - a large tuft of very long, feathery hairs hanging from the sixth segment of their abdomens.

A fourth example of an Andrena  within the subgenus Melandrena is Dunning's Mining Bee.  Like Carlin's mining bees, neighborly mining bees and the Plum Andrenas shown above, Dunning's mining bees are important generalist pollinators of spring plants.

 

Dunning's mining bees appear in the park in late April.  As noted in the introduction to this guide page,  the common name "mining bee'" derives from Andrena bees' practice of constructing nests underground.  Dunning's mining bees in particular seem most visible in the park not when pollinating flowers, but instead when scurrying along the forest floor.  The female bee shown here was exploring a crevice full of leaf-litter on a sunny April day.

 

Dunning’s mining bees are significant pollinators of April bulbs such as claytonia, bloodroot, scilla and daffodils; of native spring ephemeral woodland flowers such as Virginia waterleaf and cutleaf toothwort; and of spring-flowering native trees and shrubs, including  honey locust, redbud, willow, ninebark, viburnum and azaleas. These Andrenas are documented pollinators of blueberries, blackberries, raspberries, currants,  plums and apples. 

 

Identification Information:  Dunning's mining bees have dark rust-red thoraxes that make them easily distinguishable from the three Andrena (Melandrena) species shown above.  Like those bees, Andrena dunningi are fairly large -- about honey bee size -- with black heads and dark abdomens. The abdomens of Dunning's mining bees are smooth and without stripes. Females have robust builds and males are more slender and somewhat smaller.  Females have reddish brown foveea or "sideways eyebrows" on their faces.  Their legs are covered with pale brownish-red hairs. The male Dunning's mining bee also has a distinctive furry-looking protuberance at the end of its abdomen. 

 

Similar species:   Andrena milwaukeensis, shown farther up on this guide page,  also has orange-red thorax hairs, but on  A. milwaukeensis this hair is a much more intense orange-red and extends over part of the abdomen as well as the thorax.  Female Andrena barbilabris shown below also somewhat resemble female Dunning's mining bees:  both have a rust-red thorax hairs and a black body. The two species can be distinguished by the fact that A. barbilabris has pale bands on its abdomen while A. dunningi does not.

This is a relatively uncommon bee. The confederate mining bee emerges in our area during the first weeks of June.  It can be found occasionally feeding on hawthorn and spirea blossoms in the woodland area dividing Stone Barns from the park.  The bee shown here was found foraging in the bee garden of Stone Barns during the first week of June, 2016.

Confederate mining bees are pollinators of wild hawthorn, service berries and chestnut trees.  They are also documented pollinators of caneberries, strawberries and cherries. 

 

Identification Information:   These are striking bees, visibly different from other Andrena (Melandrena) shown above.   Confederate mining bees appear matte-black and hairless to the naked eye, and are large for Andrena - -the female bee here was nearly 3/5 inches long.  The bees have a slender, graceful build and less bulky appearance than any of the Andrena (Melandrena) shown above.  Their wings are distinctively dark, and females have pale facial foveae.  Females' legs are dark; their back legs are covered with short pale-yellow scopal hairs.  The tarsi (bottom segments) of their legs are reddish.

On closer inspection:   A distinctive trait of this species is that the vertex of the bee's head is unusually short (as shown in the photostrip at right).  The male confederate mining bee has a distinctive brush of hairs projecting from the underside of its eighth abdominal segment. The female confederate mining bee has a fringe of rust-brown hair on the outer edge of its fifth abdominal segment. 

Confederate Mining Bee

Andrena confederata
(Andrena Subgenus Melandrena)

2/5" to 3/5"  (medium-sized)

A female confederate mining bee

All photos (c) 2014 - 2016 Sharp-Eatman Nature Photography

All photos (c) 2014 - 2016 Sharp-Eatman Nature Photography

Dunning's Mining Bee

Andrena dunningi
(Andrena Subgenus Melandrena)
1/3" to 2/5"  (medium-sized)

A female Dunning's mining Bee

All photos (c) 2014 - 2016 Sharp-Eatman Nature Photography

Andrena (Melandrena) Mining Bee

Andrena Subgenus Melandrena spp.
1/3" - 1/2"  (medium-sized)

In spring, furry-looking black Andrena bees, like those shown at right, appear in significant numbers gathering pollen from tree peonies in the park's Peony Monument garden. These mining bees belong to the Andrena subgenus Melandrena.

 

Andrena (Melandrena) in our area are generalist pollinators that tend to emerge between mid-March and May and to vanish by mid-June.  They pollinate a variety of native wildflowers, among them wild roses; woodland shrubs such as viburnum, mountain laurel, ninebark and sumac; and  a range of early-blooming woodland bulbs including bloodroot, trillium, spring beauty and dogtooth violets.  In spring, Andrena (Melandrena) can be spotted along woodland paths in the park and visiting fruit trees and blueberries in Stone Barns orchards and

gardens.

The nests of Andrena (Melandrena) are often targeted by nomad bees, which are shown on the cuckoo bee page of this guide.  Yellow nomad bees (Nomada luteoloides) and spotted nomad bees (Nomada maculata) are particularly common sights during the spring in areas of the preserve and Stone Barns inhabited by Andrena (Melandrena).

 

Identification Information:  Andrena (Melandrena) mining bees are fairly large, around the size of honey bees, or slightly smaller or bigger.  Female Andrena (Melandrena) tend to have shiny black abdomens without prominent banding; black legs; and black thoraxes covered with brown, light-brown or reddish-brown hairs.  The bees' thorax hair attracts large quantities of pollen -- during tree-peony blooming season at the park, the female Andrena (Melandrena) mining bees visiting the Peony Monument often appear as if they had been rolled in yellow flour.  These bees are gathering pollen to take back to their nests.

 

Within a given species, male and female Andrena (Melandrena) may differ substantially from one another.  Males lack the facial foveae or "sideways eyebrows" typical of Andrena  females.  Instead, as shown in the photostrip a right, males may have shaggy faces rimmed on the bottom with pale mustaches.  Pale or grayish hair often covers their thoraxes and abdomens.

 

There are at least 8 species of Andrena (Melandrena) in New York and 24 within the United States. Species identification is tricky, as it may hinge on nuanced differences not easily visible to the naked eye, particularly in the case of male bees.  Five examples of Andrena Melandrena follow below -- Carlin's mining bee, the neighborly mining bee, the plum Andrena, Dunning's mining bee and the confederate mining bee.

All photos (c) 2014 - 2016 Sharp-Eatman Nature Photography

Carlin's Mining Bee

Andrena carlini
(Andrena Subgenus Melandrena)
2/5" (males)  to .55"  (females)  (medium-sized)

A notable species within the Melandrena subgenus described above is Carlin’s Mining Bee (Andrena carlini), a strong flyer with a distinctive appearance.  Carlin’s mining bees usually emerge in the park in late March and early April; in 2017, male Carlin's mining bees appeared as early as the end of February, feeding on snow drops in woods bordering Stone Barns. 

 

These bees are commonly found in the park foraging on woodland bulbs such as dogtooth violets, lily-of-the-valley, bloodroot and claytonia.  Andrena carlini bees are significant pollinators of early-blooming native spring trees and shrubs, among them dogwood, beech, red maple, willow, pussy willows, ninebark and serviceberry. 

Entomologists Martha Northam Schrader and Wallace E. LaBerge  noted in a groundbreaking article on Andrena carlini that early spring bees tend to be polylectic (plant generalists) as a survival strategy – spring plants are often felled by the vagaries of last-minute frosts and snowstorms.  Andrena carlini fits this mold.  In addition to pollinating many native bulbs, trees and shrubs, Carlin's mining bees are documented pollinators of various garden plants and crops.

Carlin’s mining bees are considered important pollinators of blueberries.  They tend to commingle in Northeastern blueberry plantings with the very similar blueberry-pollinatiing species Andrena regularis. Carlin’s mining bees also pollinate strawberries, blackberries, apples, plums and  shrubs such as boxwood, andromeda and azaleas.

These bees can be challenging to find. According to Schrader and LaBerge, female bees do not surface on spring days when the temperature drops below 55 degrees. In addition, the bees do not behave like many of the Andrenas shown on this page, which emerge suddenly in the park in fairly large groups; you’ll often find a number of Andrenas of a particular species feeding on a particular plant.  In our experience, however, Carlin's mining bees tend to appear by themselves, feeding alone on a blossoming claytonia or trout lily, amid crowds of Andrenas of other species.  

Carlin's mining bees' nests are also challenging to locate, often materializing as single holes hidden under leaf-litter or grass. Andrena carlini nests consist of sloping tunnels that lead to small cells with highly-polished walls.  To construct new cells, Andrena carlini burrow downward instead of laterally, and their cumulative nest structures thus can extend fairly deeply into the soil (to at least 10 inches). Because the bees are such determined and dynamic flyers, however, it is difficult to follow them to their nests and discover where they lie buried.

Identification Information:  Female Carlin's mining bees are robust and hefty, with black bodies, pale brown thoraxes (with black hair underneath) and legs trimmed with furry-looking black hair. They are easily mistaken for small bumble bees.  If you are able to inspect female Carlin’s mining bees closely, however, you’ll see they have typical Andrena characteristics:  heart-shaped faces and facial foveae that look like sideways eyebrows. 

Male Carlin's mining bees are much smaller and less robust than females.  Males have narrow dark abdomens covered with sparse pale hairs. Their thoraxes sport long pale hairs, as shown in the photo gallery at right.  Males' faces are covered with thick tufts of pale-intermingled-with-dark hairs.  A tell-tale trait of Andrena carlini males (viewable only with a macro lens or other magnifier) is that they have dark hairs lining the inside edges of the orbits of their compound eyes.

Carlin's mining bees are easily mistaken for bumble bees.

A male Carlin's mining bee:  Males are smaller and have narrower builds than females
This male bee has a black face and body covered with pale and black hairs.  The yellow powder on the bee's thorax , head and legs is  pollen  from the snow drop flower at left.

All photos (c) 2014 - 2017 Sharp-Eatman Nature Photography

The hawthorn mining bee is a striking Andrena with a dark, slender body and  brown wings. This bee appears in the park and Stone Barns in early and mid-June, feeding in large numbers on the white-flowered shrub known as ninebark and on spirea that has naturalized in wooded areas. 

True to its name, the hawthorn mining bee's preferred food is the flowers of hawthorn.  Nevertheless, it is an instrumental generalist pollinator of a variety of native shrubs and trees – including, for example, buckthorn, chestnut trees, chokecherry, dogwood, hawthorn, hop tree, mop orange, ninebark, red chokeberry, pin cherry, rum cherry, serviceberry, sumac, viburnum and willow.  This bee also pollinates an array of wildflowers, garden flowers and vegetables.  The hawthorn mining bee is, in addition, a key pollinator of apples, pears, cherries, blackberries, blueberries, raspberries, and strawberries.

Unlike most Andrenas, hawthorn mining bees engage in communal nesting behavior.  Many female hawthorne Andrenas may share a single nest consisting of interconnected tunnels with multiple entrances.  Females line their nests with a shiny, waterproofing material. 

Andrena crataegi are targeted by Nomada cressoni, a parasitic cuckoo bee that enters the mining bees' nests and deposits its eggs inside them.  When the cuckoo bee's larvae hatch, they kill off the Andrena young and eat the provisions left for them by their mining bee parents.

The hawthorn mining bee belongs to the subgenus Plastandrena.   Andrena crataegi does not, however, closely resemble other bees of its subgenus.  According to entomologist W. E. LaBerge, the female hawthorn mining bee differs notably from other Plastandrena  in two aspects:  (1) the bee’s head and body (underneath the hairs) are entirely black; and (2) each of the bee’s hind legs has a keel-like ridge on the lower-back edge of the femur (the long segment of the bee’s leg closest to its body).

Identification Information:  Hawthorn mining bees are medium-sized as Andrenas go, usually just under half an inch; females are slightly larger than males.  With the naked eye, females look black with yellow legs and dark wings. (In fact, their legs are black, but have pale-yellow hairs on them.)  Female bees have a large brush of yellow scopal hair on each  back leg and broad pale facial foveae (“sideways eyebrows”) visible even to the casual observer.  Males are dark and slender with long antennae and have pale hairs on their faces; short yellowish hairs on their legs; and white  hairs on their thoraxes.

On closer inspection:  The female hawthorn mining bee's abdomen has poorly-defined bands of pale hair on segments 2-4 and a fringe of hair on the outer edge of segment five.  The bee’s tegulae (where the wings attach) are reddish, and its wings are brown with reddish veins. The female hawthorn mining bee has a curved spur on the tibia (the second long segment) of each hind leg; this distinctive feature helps differentiate this bee from similar black Andrenas.  The male mining bee has a relatively small head and narrow gena (cheek), and a "recurved" sixth abdominal segment. These features are shown in the photostrip at right.

Some minute distinctions, viewable only with a macro lens or microcscope, help differentiate this bee from the mostly black confederate mining bee higher up on this page. The confederate mining bee tends to be larger; it has a median line on its clypeus, while the hawthorn mining bee often does not; and the confederate mining bee has a narrow vertex (as shown in the photostrip to the right of that bee), while the hawthorn mining bee has a fairly broad vertex.  The thorax of the hawthorn mining bee is pitted, while that of the confederate mining bee looks matte and unpitted except on microscopic inspection. The propodeal triangle of the hawthorn bee's thorax is finely wrinkled.

Hawthorn Mining Bee

Andrena crataegi
(Andrena Subgenus Plastandrena)
2/5"  (medium-small)

A male hawthorn mining bee

A female hawthorn mining bee

All photos (c) 2014 - 2016 Sharp-Eatman Nature Photography

A female Wilkes mining bee on cow vetch

A male Wilkes mining bee on thyme

All photos (c) 2014 - 2016 Sharp-Eatman Nature Photography

Wilkes Andrena

Andrena Wilkella
(Andrena Subgenus Taeniandrena)
1/3" - 2/5"  (small to medium-small)

Wilkes Andrenas belong to the subgenus Taeniandrena.  These are graceful, elegant bees with long abdomens, narrow waists, delicate wide heads (shaped a little like ET's head), long antennae and seed-shaped eyes.  Their abdomens are  black and circled by faint bands of white hair. From a distance, female bees appear brown with  yellow hind legs.  Males look furry:  pale white hairs protrude from their legs, heads and thoraxes.

 

Native to Europe, Wilkes Andrena bees (also known as Wilke's Meadow mining bees) are thought to have been transported inadvertently to America long ago by ships that carried nesting bees commingled with ship ballast.  According to the Bees, Wasps and Ants Recording Society of Great Britain, Wilkes Andrenas frequent flower-rich grasslands, woodlands and flower gardens.

 

Wilkes Andrenas are often categorized as specialist bees that focus principally on clover and vetch. These bees appear in pasture areas of the rockford Hall section of Rockefeller State Park Preserve, in areas where cow vetch (Vicia villosa) self-seeds.  At Stone Barns, the bees are easiest to find feeding on white clover and cow vetch, planted as cover crops in the vegetable fields.  Nevertheless, Wilkes Andrenas are also common visitors to Stone Barns' herb gardens, where they favor flowering thyme.  The males bees shown here are feeding on thyme blossoms.

 

Female Wilkes Andrenas build solitary nests but are sometimes found in enormous aggregations. The females lay their eggs in the fall, and the larvae overwinter and emerge as adults in spring. Male Andrenas often appear in large numbers foraging for nectar amid flowering thyme in late spring and early summer. These bees disappear from sight in the park and Stone Barns by the end of July.

Long-lipped Mining Bee

Andrena barbilabris
(Andrena Subgenus Leucandrena)
.4" (males)  to .55"  (females)"  (medium-sized)

The Andrena subgenus Leucandrena is represented by only two species in our area – the trout-lily mining bee (A. erythronii) and the long-lipped mining bee (A. barbilabris), shown here.  According to entomologist Charles D. Michener, bees of this subgenus have pale bands of hair circling the second through fourth segments of their abdomens; the bands are interrupted in the middle.  They also have  narrow and elongated lower faces.

 

The long-lipped mining bee is found throughout the Northern Hemisphere, in areas as far-flung as Alaska, Japan and Great Britain. In New York, Andrena barbilabris bees emerge in early spring. The bee shown here was found foraging in mid-April in a field in the Rockwood Park section of Rockefeller State Park Preserve. 

 

Andrena barbilabris bees are solitary. They prefer nesting in bare ground, particularly in sandy soils -- although in the park, these bees seem content with loamy soils on the edges of woodlands. Female bees vibrate their wings and buzz as they dig through the sand and dirt to find their burrows, looking as if they are “swimming” in the ground. Once settled, individual bees rarely travel more than than 650 yards from their nests.

 

Long-lipped Andrenas are documented pollinators of spring-blooming native plants such as  willow, serviceberry, chokecherry, American plum and wild berries.  Andrena barbilabris is also known to pollinate apples; garden trees and shrubs such as cornelian cherry and rhododendron; and common plants like dandelion, winter cress, mustard, phacelia and potentilla.

 

In Europe, these Andrenas are preyed on by the cleptoparasitic bee, Sphecodes pellucidus.  This bee enters the Andrenas’ nests and deposits its eggs there.  When the Sphecode young hatch, they kill the Andrena larvae in the nest and devour provisions left for them by the parent Andrena.

 

Identification Information:   Male and female long-lipped mining bees differ substantially in appearance. Female Andrena barbilabris are medium-small bees with striking rust-orange thoraxes.  They have black heads; black abdomens banded by interrupted rings of pale hairs on the second, third and fourth abdominal segments; and legs covered with long pale hairs.  Viewed minutely, the bees have large mandibles and narrow, elongated faces that are said to give them a hunchbacked appearance.  The foveae or “sideways eyebrows” on the faces of the female bees are pale brown. Females also have sizeable jaws and barbs on their lower faces (labrums).

 

Male Andrena barbilabris bees are smaller than females, and their thoraxes are covered with gray rather than rust-orange hairs.  Like the females, males have black heads and black abdomens ringed with interrupted white bands on the second, third and fourth segments.  Males' faces sport shaggy hairs that look like white moustaches.  From afar, male Andrena barbilabris bees appear gray and hairy.

 

Similar species:  Female Andrena barbilabris bees somewhat resemble females of the mining bee species Andrena dunningi (shown above), which also have rust-red thorax hairs and black bodies.  The two species can be distinguished by the fact that A. barbilabris has pale bands on its abdomen while A. dunningi does not. 

 

Female long-lipped mining bees bear a striking resemblance to male Colletes thoracicus cellophane bees (shown on this guide's cellophane bee page).  Male thoracic cellophane bees also have golden-reddish thorax hairs and black abdomens banded by pale hairs.  (Female cellophane bees of this species lack the pale abdominal bands and thus can be more easily told apart from Andrena barbilabris females.The easiest way to distinguish  male Colletes thoracicus bees from long-lipped mining bee females is to determine the bees' gender:  all male bees have 7 abdominal segments and 13 segments on each antenna; females have 6 abdominal segments and 12 segments on each antenna. 

Female Long-lipped mining bees have rust-orange hair on their thoraxes and
black abdomens encircled by broken pale bands.

All photos (c) 2014 - 2016 Sharp-Eatman Nature Photography

Blueberries are native to the American Northeast, and they are a food source for a broad spectrum of wild bees.  Blueberries are cultivated at Stone Barns Center for Food and Agriculture in a long swatch bordering the center’s vegetable gardens.  Rockefeller State Park Preserve has well-established blueberry bushes growing amid other native plants in its Visitor’s Center garden. Blueberries also can be found on the edge of the park's Swan Lake.

 

In all three locations, the bushes blossom in the last week of April and early May.  The blueberries' flowers attract honey bees, common eastern bumble bees, carpenter bees, mason bees, and several species of mining bees – among them, Carlin’s mining bee, neighborly mining bees and, most notably, Bradley’s Mining Bee.

 

Bradley’s mining bees are found only in North America.  They are pollinator specialists that focus on Vaccinium, the plant genus that includes native blueberries and cranberries -- as well as wild huckleberries, deerberries and bilberries.

 

Despite their confirmed status as pollinator specialists, Bradley's mining bees occasionally can be found visiting a select array of other plants. The flowers of blueberries have an unusual shape – they look a little like miniature hurricane lamps. Bradley’s Mining bees have been documented visiting one exotic plant whose flowers have a similar shape – Pieris japonica, the popular garden shrub known commonly as Andromeda.  Bradley’s mining bees also visit willow and mountain laurel, two native plants that appear in the bog environments where blueberries and Andrena bradleyi evolved.

 

Bradley’s mining bees are mainstays of commercial blueberry farms in the Northeast.  The bees often nest in the sandy soil in which blueberries tend to be planted.  Andrena bradleyi bees cover their nests completely with sand and are said to appear as if they were “swimming” through sand when leaving and entering their nest tunnels.  At the park and Stone Barns, the bees seem content to build nests in humus-rich soil, or in the cherry-tree-sawdust used by Stone Barns to mulch blueberry plants.

 

Identification Information:  Bradley’s mining bees belong to the very small Andrena subgenus Conandrena.  According to entomologist Charles D. Michener, members of this subgenus are distinguished by their pale thorax hair and long faces. 

 

One aid in identifying Bradley mining bees is their proximity to blueberry bushes.  Within that element, female Bradley’s mining bees stand out from other blueberry-attracted Andrena because Andrena bradleyi bees appear distinctly pale and furry with abdominal bands.   In our area, the most common and visible Andrena visitors to blueberries are A. carlini and A. vicina (shown above), both of which have dark abdomens that flash like black patent leather when they curl head-down in blueberry flowers.  Bradley’s mining bees are also smaller than many females of those species – both male and female Bradley’s mining bees are about one third inch or smaller.

 

Both male and female Bradley’s Mining bees have dark heads, thoraxes covered with pale hairs and abdomens banded with faint pale stripes.  Blueberry pollen is white, and in April, female Bradley's mining bees caught in the activity of gathering blueberry pollen often appear smeared from head to tail with white dust – as shown in the photo strip at right, the bees carry large amounts of pollen on their hind legs, and the pollen tends to stick to their thorax hairs and even their undersides.   

 

Viewed minutely, both male and female Bradley’s mining bees have distinctive facial characteristics. Females have protuberant faces with long heads and convex “roman noses”—as shown in the photo strip at right.  On male bees, the bottom portion of the clypeus (located on the lower face) sports a triangular yellow mask. 

Bradley's Mining Bee

Andrena bradleyi
(Andrena Subgenus Conandrena)
3/10" - 1/3"  (small-to-medium-sized)

Female Andrena bradleyi bees have unusally long faces and roman noses.

Female Andrena bradleyi also have large jaws.

All photos (c) 2014 - 2016 Sharp-Eatman Nature Photography

A  female Alleghany Mining Bee (Andrena alleghaniensis) on a Dogwood Blossom

In the first two weeks of May, wild dogwood trees bloom throughout Rockefeller State Park Preserve.  Various Andrena species pollinate dogwood, among them the beautiful Alleghany mining bee, a small Andrena that looks as if it is wearing orange epaulets on its shoulders.  This bee appears in the park in mid-May and disappears by the end of June.

 

This is the sole bee in this guide that represents the Andrena subgenus Scrapteropsis.  Entomologist Charles D. Michener recorded two species in this subgenus, noting that Scapteropsis mining bees live throughout North America, from Alberta, Canada to Baja California, Mexico. The Discover Life database has recorded eight species of Scrapteropsis in the Northeastern United States.

 

Identification Information:  The Alleghany mining bee has a dark head; dark thorax; and dark abdomen encircled by pale hairs. The hair on the top of the bee's thorax is unusually sparse; where present, it is rust-orange to pale yellowish. 

 

The Alleghany Mining Bee's most dramatic trait visible to the naked eye is the presence of two brightly-colored rust-orange tufts of hair on either side of the front end of the thorax.  This Andrena has two other distinctive characteristics, as shown in the photostrip at right.  The bee's thorax is deeply pitted.  The propodeum (back end) of the bee's thorax also looks as if it is wrinkled.   (These last two traits are shared by members of the Andrena subgenus Trachandrena; the rugose Andrena, for example, generally resembles the Alleghany mining bee, but lacks its orange epaulets.)

 

Female Alleghany mining bees have pale-orange foveae (sometimes called "sideways eyebrows") and fairly long blonde hairs on their back legs.  Although impossible to see without the aid of strong magnification, the female Alleghany mining bee also has what the Discover Life Database describes as "two curious, irregular ridges" on the underside of the second segment of its back leg. 

 

Alleghany mining bees are generalist pollinators that visit woodland trees and shrubs including willow, New Jersey tea, holly and viburnum.  These bees also feed on wildflowers such as buttercups, golden ragwort, melilot and ox-eye daisies.  Andrena alleghaniensis bees are documented pollinators of caneberries, blueberries and melons  -- they are common visitors to Stone Barns' cultivated raspberries during the second and third week of May.  The Alleghany mining bee shown above right was found collecting pollen from a dogwood blossom in the park during May, 2016.

Alleghany Mining Bee

Andrena alleghaniensis
(Andrena Subgenus Scrapteropsis)
3/10" - 2/5"   (small)

All photos (c) 2014 - 2017 Sharp-Eatman Nature Photography

Forbes' Mining Bee

Andrena forbesii
(Andrena Subgenus Trachandrena)
2/5" (males)  to .55"  (females)  (medium-sized)

Like the Rugose Andrena shown above, Forbes' Andrena belongs to the subgenus Trachandrena.  True to this subgenus, Forbes Andrena is a relatively small mining bee with a heavily pitted thorax and a wrinkled propedeum (the top part of the thorax, closest to the abdomen).

Forbes Andrenas are most visible in the park in mid-May, at the time when chokecherry trees begin to bloom in large numbers throughout the woods in our area.  Male bees often appear in groups of several or more, buzzing around black cherry blossoms, landing on them only briefly. 

 

Forbes Andrenas are generalist pollinators of many woodland trees and shrubs – among them dogwood, willow, maple, magnolia, black cherry, viburnum,  serviceberry, hawthorne, chokecherry, chokeberry and ninebark.  They also pollinate an array of commercial fruit crops, including cherries, apples, pears, blueberries and blackberries.


Identification Information.  Forbes' Andrenas are around 1/3” long, with sparse, pale-rust-colored hair covering their visibly pitted thoraxes.  Like other Trachandrena, female Forbes mining bees have narrow facial foveae (the "sideways eyebrows" on the fronts of their faces).

​​As noted in the entry above on Rugose Andrenas, male Trachandrena  can be difficult to distinguish from one another.  Male Forbes' Andrenas are somewhat easier to identify than other male Trachandrena, because of a singular trait, albeit one detectable only under a macro lens or microscope -- the male bee's antennae have a shiny, patent-leather look.  This trait is shown in the photo strip at right.

The entomologist LaBerge called Forbes' Andrena a "nondescript bee".  He noted that females can be distinguished from similar Trachandrena females by two minute traits(1) dense puncture marks on the top of the second segment of their abdomens; and (2) the relatively straight spurs on their hind legs.

A female Wilkes mining bee on cow vetch 

Other Andrenas of Spring and Summer

A male mining bee  of the Subgenus Trachandrena 

Rugose Mining Bee

Andrena rugosa
(Andrena Subgenus Trachandrena)
2/5" (males)  to .55"  (females)  (medium-sized)

The subgenus Trachandrena embraces at least ten species of mining bees found in New York State.  Trachandrena are notably cold-hardy. According to entomologist Charles D. Michener, author of The Bees of the World, members of this subgenus live as far north as Alaska. 

Andrena (Trachandrena)  are small bees -- they tend to be less than ten millimeters (2/5")  in length. They are closely related to bees of the subgenus Scarrapteropsis -- the subgenus to which the Alleghany mining bee shown directly above belongs -- and resemble them.  Like Andrena (Scrapteropsis), Andrena (Trachandrena) tend to have pitted thoraxes, and their propodeums (the back ends of their thoraxes) look wrinkled.  Female Andrena (Trachandrena) have narrow facial fovea in the lower halves of their faces.
 

​​​Rugose Andrenas appear in the park in mid- April, as the first dogwoods begin to bloom.  They are generalist pollinators that visit a broad range of woodland trees and shrubs such as beech, willow, red maple, ninebark, service berry, pin cherry,  hawthorn, mountain laurel and viburnum.  Rugose Andrenas also visit early spring wildflowers such as claytonia, hepatica and wild geranium. They are well-documented pollinators of  blueberries.

Identification Information.  Rugose Andrenas are small Trachandrena,  about 1/3” long, with faint pale bands on their abdomens and sparse hair covering their visibly pitted thoraxes.  The hair on the bees' thoraxes is rust-orange to pale yellowish.  Females have pale-orange foveae and fairly thick blonde hairs on their back legs.

 

 “Rugosa” means “wrinkled” in Latin.  This name derives from the fact that the Andrena rugosa, true to its subgenus,  has wrinkle-like marks on its propodeum (the hindmost part of its thorax).  This trait is shown in the photo strip at right.

Distinguishing among male species of Trachandrena can be tricky and require a microscope.  The small male bee shown above right, which measured one-third inch, was tentatively identified as Andrena rugosa.  Nevertheless, the bee's identity remains uncertain, because it closely resembles several other New York Trachandrena species, among them, Andrena hippotes and Andrena sigmundi.  All three of these are small bees with pale brownish hairs on their faces, thoraxes and legs; pitted thoraxes; and wrinkled propedeums.

A female rugose mining bee 

All photos (c) 2014 - 2017 Sharp-Eatman Nature Photography

A male Forbes' mining bee

All photos (c) 2014 - 2017 Sharp-Eatman Nature Photography

Like the cloudy-winged mining bee directly above, hairy-banded mining bees occupy the Andrena subgenus Cnemidandrena and appear in the park at the end of summer. 

 

The hairy-banded mining bee is a specialist pollinator that feeds principally on goldenrod.  The bees shown here were found foraging on goldenrod on the sunny edge of a park trail at the end of August and beginning of September.  Hairy- banded mining bees also feed on a handful of other late-blooming wildflowers, among them, wild asters, groundsel, daisies and common melilot.

Hairy-banded Andrenas are preyed on by the autumn cuckoo bee species Nomada vicina, also known as the neighborly nomad bee.  This cuckoo bee enters hairy-banded Andrena nests and lays its eggs in them.  When the cuckoo bee larvae hatch, they kill off any Andrena hatchlings and eat the provisions stored in the nest by the mother Andrena for her offspring.

 

Identifying Traits:   These Andrenas are striking bees because of their furry apearance:  their thoraxes are covered with long yellow hairs with a greenish tinge, and their abdomens are banded by long yellowish hairs as well.

 

These are medium-sized Andrena.s.  Females are more robust than males and around 2/5" in length.  Males tend to be slightly smaller, around 1/3",  as shown in the photo strip at right.  Males have tear-shaped abdomens and faces covered with thick yellowish hair. Females have dark faces and jaws and pale facial foveae ("sideways eyebrows") on the inner edges of their compound eyes.

Hairy-banded Mining Bee
Andrena hirticincta
(Subgenus Cnemidandrena)

1/3" - 2/5"  (medium-sized)

A female hairy-banded mining bee

Simple Mining Bee / Placid Mining Bee

Andrena simplex / Andrena placata
(Andrena Subgenus Callandrena sensu lato)
3/10 - 7/16"  (medium-small)

According to the entomologist W. E. LaBerge, Andrena placata and Andrena simplex are two species that are so similar that they occasionally mate and hybridize.  Like mules bred from donkeys and horses, the Andrenas'  offspring are infertile. They also possess characteristics exactly intermediate between the two species.

Andrena placata and simplex are late-summer bees that emerge in August in our area in tandem with the bloom period of end-of-summer flowers. Both Andrena placata and Andrena simplex are oligolectic (visiting a limited variety of plant species, often within a single genus).  They specialize in pollinating and foraging on goldenrod and wild asters, both members of the plant family Asteraceae. They linger in the park though the fall.  The bee shown here was found feeding on goldenrod in late August.

Like most Andrenas, these bees are ground nesters. Andrena placata have been shown to be adaptive to city environments as well as the woodland environment of the park:  a 2009 study of bees in East Harlem and the Bronx documented Andrena placata living in urban gardens.

Identification Information:  Andrena placata and A. simplex males and females are predominantly black bees with dark thoraxes that are bald on top and fringed with pale hairs on the sides; and dark abdomens encircled by weakly-defined pale bands of hair. The jaws of both males and females have reddish tips.  On males, the clypeus (the face part above the jaws) is yellow with a stripe of brown on the bottom edge, and two black dots that resemble  false nostrils. Males and females have relatively short antennae.

Male Andrena placata can be distinguished from male Andrena simplex in part by the fact that the former’s abdominal segments are shinier and more distinctly pitted than the latter’s. In addition, on Andrena placata, the third flagellar segment of each antenna is longer than the second. 

Female Andrena placata can be distinguished from female Andrena simplex by equally minute traits:  on the female Andrena placata, the third flagellar segment of each antenna is slightly longer than the second; the bee’s facial foveae extend father down the bee’s face, and the bee’s abdomen is shinier and more visibly pitted.

A male hairy-banded mining bee

The Andrena bees shown above come out in spring and  forage on a range of flowers.  Cloudy-winged mining bees, however, are specialist pollinators that emerge at the end of summer to feed on late-blooming goldenrod and wild asters.  If you closely examine any goldenrod plant in the park after mid-August, you are likely to find one of these minute Andrena bees busily gathering pollen from the flowers. Stone Barns has made a singular effort to plant several goldenrod species in and around garden areas, and thus these bees are particularly plentiful there.  Andrena nubecula bees remain visible through mid-fall, as long as goldenrod and asters are still in bloom.

 

You might notice that after milkweed is done flowering in July, there are relatively few plants in bloom in the wild areas of Rockefeller State Park Preserve.  Generalist bees such as the common eastern bumble bee are condemned to forage along trail edges through slim pickings, usually low-lying toadflax and other tough weeds, a sharp contrast to the wealth of blooms on which pollinators feed during mid-July in the park.  Healthy populations of specialist pollinators such as the cloudy-winged mining bee serve the key function of augmenting the propagation of late bloomers like goldenrod and asters, insuring that not only Andrena bees, but other generalist pollinators, have a sufficient food supply.  

 

Identifying Traits:   Cloudy-winged mining bees (Andrena nubecula) occupy a different subgenus (Cnemidandrena) than any of the Andrena mining bees shown above. Andrena nubecula bees are blackish-brown with slender, black abdomens ringed by well-defined white stripes.  The cloudy-winged mining bee is best recognized by two traits:  (1) it has dark wing tips; and (2) the first segment of the bee's abdomen lacks a white band.  Female cloudy-winged mining bees have narrow facial foveae.  They are larger than the males:  females run as large as one third inch; males can be as small as 1/5".

 

Cloudy-winged mining bees are somewhat similar in appearance to the ligated sweat bee shown in the Sweat Bee section of this guide. One way to distinguish these two species from one another is to observe how the bees carry pollen.  Andrena females, as noted in the introductory section of this guide page, carry pollen under the upper part of their hind legs – under their “armpits”.  (Sweat bees, by contrast, carry pollen on brushes located lower down on their hind legs.)  To the naked eye, the white stripes on the abdomens of cloudy-winged mining bees also appear more crisply defined than those of ligated sweat bees.  In addition, as noted, cloudy-winged mining bees tend to carry their wings in a distinctive way, angled in a V-shape above their bodies, displaying their dark wing tips.

Cloudy-winged Mining Bee

Andrena nubecula
(Andrena Subgenus Cnemidandrena)
1/5" - 1/3"  (small)

A male Cloudy-winged Mining Bee

A female Cloudy-winged Mining Bee

A male Andrena placata (or Andrena simplex) 

A female Andrena placata (or Andrena simplex) 

All photos (c) 2014 - 2016 Sharp-Eatman Nature Photography

All photos (c) 2014 - 2016 Sharp-Eatman Nature Photography

All photos (c) 2014 - 2016 Sharp-Eatman Nature Photography

COPYRIGHT:  This website's photos and text are protected by registered copyright. All photos are © 2014-2017 Paula Sharp & Ross Eatman, all rights reserved.  To inquire about possible use of photos, see Permissions. 

 

REFERENCES:  For a comprehensive list of references used in compiling this guide, click here:

Andrenas of Late Summer and Fall

 8-23-15