Bee Basics 

An Introduction to Our Native Bees 

By Beatriz Moisset, Ph.D. 

and 

Stephen Buchmann, Ph.D.

A USDA Forest Service 

and

 Pollinator Partnership Publication
Cover Art:

Upper panel: The southeastern blueberry bee (Habropoda laboriosa) 

visiting blossoms of Rabbiteye blueberry (Vaccinium virgatum).

Lower panel: Female andrenid bees (Andrena cornelli) foraging for 

nectar on Azalea (Rhododendron canescens). 
Bee Basics:

An Introduction to 

Our Native Bees

By Beatriz Moisset, Ph.D. 

and 

Stephen Buchmann, Ph.D.

Illustrations by Steve Buchanan

 A USDA Forest Service and Pollinator Partnership Publication
Acknowledgments

Edited by Larry Stritch, Ph.D.

Julie Nelson

Teresa Prendusi 

Laurie Davies Adams

 A USDA Forest Service and Pollinator Partnership Publication

United States Department of Agriculture
1

Introduction

Native bees are a hidden treasure. From alpine meadows in the national 

forests of the Rocky Mountains to the Sonoran Desert in the Coronado 

National Forest in Arizona and from the boreal forests of the Tongass National 

Forest in Alaska to the Ocala National Forest in Florida, bees can be found 

anywhere in North America, where flowers bloom. From forests to farms, from 

cities to wildlands, there are 4,000 native bee species in the United States, from 

the tiny Perdita minima to large carpenter bees. 

Most people do not realize that there were no honey bees in America before 

European settlers brought hives from Europe. These resourceful animals 

promptly managed to escape from domestication. As they had done for 

millennia in Europe and Asia, honey bees formed swarms and set up nests in 

hollow trees. Native pollinators, especially bees other than honey bees, have 

been pollinating the continent’s flowering plants since long before the arrival of 

honey bees. Even in today’s vastly altered landscapes, they continue to do the 

yeomen’s share of pollination, especially when it comes to native plants.

The honey bee, remarkable as it is, does not know how to pollinate tomato or 

eggplant flowers. It does very poorly compared to native bees when pollinating 

many native plants, such as pumpkins, cherries, blueberries, and cranberries. 

Let us take a closer look at this forgotten treasure of native bees.

Worker honey bees (Apis 

mellifera) visiting almond 

blossoms (Prunus dulcis).
2

Native Bees: Varied and Valuable

Native bees come in a wide array of sizes, shapes, and colors. They are also 

varied in their life styles, the places they frequent, the nests they build, the 

flowers they visit, and their season of activity. They remain ignored or unknown 

by most of us. Yet, they provide an invaluable ecosystem service, pollination, 

to 80 percent of flowering plants. What would our world be like without the 

beauty of flowering trees, shrubs, and wildflowers? How many of us know 

that bees pollinate approximately 75 percent of the fruits, nuts, and vegetables 

grown in this country?

Bees are efficient foragers. One example is the southeastern blueberry bee, 

Habropoda laboriosa, a hard working little creature capable of visiting as many 

as 50,000 blueberry flowers in her short life and pollinating enough of them to 

produce more than 6,000 ripe blueberries. At market those 6,000 blueberries 

are worth approximately $20 or more. Not every bee that you see flitting about 

may be worth $20, but all of them combined keep the world of flowering 

plants going. The world as we know it would not exist if there were no bees to 

pollinate the earth’s 250,000 flowering plants. 

U.S.’s smallest bee (Perdita 

minima) face to face with a 

female large carpenter bee 

(Xylocopa varipuncta).
3

From Whence They Came: Bees’ Heritage

Bees are descended from wasps. Most wasps are carnivores; they either prey 

upon or parasitize other insects or spiders, and use this rich protein source to 

feed their young. About 125 million years ago, when the first flowering plants 

evolved, some wasps made a switch from hunting prey to gathering pollen 

for their brood. Perhaps they were hunting for insects that visited flowers and 

ate some of the pollen or drank the nectar along with their prey. It didn’t take 

much to find the advantages of consuming pollen over hunting. Pollen is rich 

in proteins and doesn’t fight back, so it is easy to imagine why the bees became 

vegetarians. Gathering pollen and nectar requires certain adaptations different 

from those of hunters, so they started to change, to evolve to meet these 

requirements and consequently became bees.

Even today, there are bees that appear very similar to wasps. Like wasps, 

some bees are also nearly hairless; and like female wasps, only female bees have 

stingers. 

The similarities do not stop with physical appearance. Both bees and wasps 

have species that are solitary (living and raising their brood alone) or social 

(living together and sharing the rearing and provisioning). For example, 

bumble bees and yellow jacket wasps are social and have an annual colony. In 

both, an over-wintering queen emerges in the spring. The queen builds a nest, 

collects food, and lays eggs. The female workers hatch and work together to 

feed and care for the colony until fall when new queens emerge, mate, and 

hibernate until the following spring when the cycle begins anew. 

Bees or Wasps? 

Upper left: An eastern yellowjacket wasp (Vespula 

maculifrons)

Lower left: The familiar 

black and yellow mud 

dauber wasp (Sceliphron 

caementarium)

Upper right: A digger bee, 

in the genus Diadasia

Lower right: The nomad 

bee, within the genus 

Nomada
4

Bee Anatomy or 

Morphology

Like all insects, bee bodies are 

comprised of a head, thorax, and 

abdomen. They also have six legs and 

two pairs of wings.

The head features:

•	 two antennae that are used to 

touch and “smell”; 

•	 two compound eyes and three 

simple eyes;

•	 mandibles or jaws used for 

biting, working wax and pollen 

“loaves,” and digging.

The thorax features:

•	 two pairs of membranous wings, 

linked in flight by minute hooks;

•	 three pair of legs.

The abdomen features:

•	 six segments in females, seven 

segments in males;

•	 internal wax glands (only in 

honey bees and bumble bees);

•	 a stinger (modified ovipositor) 

at the tip (females only);

•	 branched hairs (plumose) 

SOMEWHERE on the body.

Some females have pollen transport 

structures, called scopae, made of stiff 

hairs located on the hind legs or under 

the abdomen. Bees frequently brush 

themselves, gathering pollen grains 

from their body’s feathery hairs and 

transferring the pollen grains to their 

transport structure.
5

A male digger bee (Anthophora 

centriformis) with major body 

parts labeled. Inset shows pollen 

grains caught in the branched hairs 

that distinguish bees from wasps.
6

Ecologically, bees can be separated into two groups based on the relative 

length of mouthpart segments within their tongues, called proboscides. The 

long and short tongues are used to gather 

nectar. 

Some long-tongued bees like 

Apidae and Megachilidae, 

favor deep flowers with a 

A long-tongued bee 

(Anthophora centriformis) 

drinking nectar from 

a beardstongue flower 

(Penstemon parryi).

 A short-tongued bee in the genus 

Colletes taking nectar from the 

shallow florets of a sunflower 

(Helianthus annuus) 

 
7

longer throat; they are not averse to collecting nectar from open flat flowers. 

The remaining families are made up of short-tongued bees and are more 

limited in their floral choices. They are only able to take advantage of shallow 

flowers, such as those of the daisy or aster family and those of the carrot family. 

Generally, females are larger than male bees, although there may be some 

overlap in size.

Nesting 

All bee families have species that take care of their young, by building nests 

and providing food for them. But several families, Apidae, Halictidae, and 

Megachilidae, have some species that take advantage of their relatives. They 

have become “cuckoos,” just like there are cuckoos among birds. As with 

cuckoo birds (like cowbirds), cuckoo bees lay their eggs in the nests of others. 

Most species of cuckoo bees only lay their eggs in the nests of a few bee species. 

There are cuckoo bee species that only parasitize the nests of a single species. 

In some species of cuckoo bees, the female kills the host’s larva before laying 

her egg. However, the majority of cuckoo bee larvae feed on the stored food 

and the larvae of the unfortunate hosts. Cuckoo bees do not gather pollen and 

have lost their pollen baskets and much of their hair. In fact, at first glance 

some cuckoo bees are often mistaken for wasps. Cuckoo bees do visit flowers 

to feed on the flower’s nectar.

Aside from cuckoo bees, all bees build nests, stocking them with a nutritious 

mixture of pollen, nectar, and saliva before laying their eggs, and sealing them 

so the larvae remain safe. They generally mix the dry pollen with some nectar, 

kneading it into a pollen loaf used to feed their young. They add their own 

saliva to this mixture. The saliva is thought to be an important ingredient that 

provides protection against bacterial and fungal infections.

Some native bees build their nests underground; others use hollow stems or 

holes in trees, usually left by beetles; and some use their powerful jaws to make 

holes in wood. Whatever their method, they start the job of nest building by 

carefully choosing the best real estate; if conditions are not right, they continue 

their search. It would not do to have their homes flooded or lacking enough 

sunshine, or being too large or too small for their needs. Except for honey 

bees and bumble bees, females of solitary bees provide in one cell all the food 

required by their larvae to become an adult. This is called mass provisioning.
8

Nesting Practices Differ

Miners 

Some members of the larger families, Apidae, Andrenidae, Halictidae, 

Megachilidae, and Colletidae, are ground nesters. They choose a bare, sunny 

spot with little likelihood of flooding and start the task of digging, which may 

take several days. They excavate a long tunnel slightly wider than their own 

bodies. Some don’t tolerate any neighbors around; others prefer the company 

of their own species (who may or may not be relatives). These groups may 

aggregate their nests, but they still remain solitary in the sense that each bee 

digs her own nest and provisions her own brood. Still other bees show different 

levels of cooperation, sharing the tasks of nest building and food provisioning. 

The underground burrow can be a foot long or even deeper. It may twist 

halfway or take a turn near the end. At the end of the tunnel, the female bee 

builds a chamber (called a brood cell) a little wider than the tunnel. A brood 

cell will be the nursery for just one baby, called a larva. The mother bee fills the 

brood cell with enough pollen and nectar for just one bee to grow from egg 

to adult. She then lays an egg and seals the chamber. She may add other 

branches to the tunnel; at the end of each, there will be another brood 

cell properly stocked with pollen and nectar and containing an egg. 

Underground features of the nest 

of a mining bee (e.g. Diadasia or 

Melissodes). Cells show larvae 

feeding upon bright orange pollen 

masses. Inset shows an early instar 

feeding on pollen and nectar provision masses. 
9

Imagine a bunch of grapes; that is what some of the underground solitary mining 

bee nests look like.

Hole-Nesters: Masons and Leafcutters

Members of several families take advantage of already existing holes. These 

bees use hollow stems or holes made by beetles or other insects in dead wood. 

Still other bees locate and use rock crevices or surfaces to form their nests. There, 

they construct brood cells, usually lined up end-to-end in a row, which they 

individually stock one by one to serve as nurseries and growth chambers for the 

larvae, pupae, and young adults.

Most members of the family Megachilidae, mason and leafcutter bees, are hole 

(rarely ground) nesters who use certain materials to modify their nest chambers. 

Some use mud to construct partition walls between adjacent cells and a thicker 

plug to seal the nest entrance from parasites. These bees are called mason bees. 

Others cut rounded leaf pieces for the same purpose, to line the inner walls of 

the nest burrow; they are called leafcutter bees. You may have seen those nearly 

perfect circles neatly clipped from the leaves of your prize rose bushes. Please, 

don’t begrudge this housing material to such hard working mothers. Bees 

require more than pollen and nectar; and like birds, they depend upon 

collecting nest-building materials and finding suitable habitats in which 

to forage and live.

A female leafcutter bee 

(Megachile sp.) transports a cut 

leaf she will use as liner for her 

brood cells. Characteristic cuts 

made by these bees in leaf margins 

are shown behind.
10

Carpenters

Some bees create burrows, or holes, of their own making. They have 

powerful jaws called mandibles with which they can excavate tunnels in 

wood. Fortunately they prefer soft wood and dislike paint or other finishing 

materials. It is possible to prevent them from doing serious damage to wood 

structures by taking simple precautions, such as painting or staining the 

wood. These gentle giants are called carpenter bees, and very likely you have 

seen some of them and their handiwork. There is usually a pile of sawdust 

below the opening of the hole during the early nesting and burrow excavation 

season. These bees create “particle board” spiral partitions between adjacent 

cells. Most bees construct spiral partition cell closures, a trademark of bees 

rather than wasps.

Foraging Needs and Floral Specialization

Some bees are generalists and will use pollen from a wide variety of 

flowering plants. Bumble bees are generalists as they depend upon a 

Excavated nest with 

branched tunnels made 

by the eastern carpenter 

bee (Xylocopa 

virginica) inside wood 

of a dead log.
11

succession of plants flowering from early spring when the queen emerges to 

late summer – early fall when the colony dies. Other bees have some degree 

of specialization in foraging; they resort to using pollen from only one or two 

families of flowering plants. Fortunately plant reproduction has redundancy in 

floral visitation already built in. Each flowering plant species usually has a small 

guild of bees and other pollinators which coevolved with them to ensure their 

pollination. Typically, bees collect nectar from a wider range of blossoms than 

they visit for pollen.

One example of floral specialization is squash bees which are efficient 

visitors and pollinators of cucurbit plants (squash, pumpkin, and zucchini). 

Blueberry bees, globe mallow bees, and cactus bees are also floral specialists. 

Some bee species are active only for a few weeks during the growing season 

and depend on just a few families of flowering plants for their 

foraging needs. Bees in the genus Macropis depend only 

on loosestrife flowers (Lysimachia) from which they 

collect oil and pollen for their larvae’s food. Loosestrife 

flowers however, have no nectar available so bees 

in the genus Macropis must visit other flowers for 

their nectar needs. One highly specialized bee is 

Anthemurgus passiflorae. This bee is only 

known to forage on yellow passionflower 

(Passiflora lutea). 

Female Macropis nuda bees collect 

floral oils from specialized glands of 

the spotted loosestrife (Lysimachia 

punctata).
12

Most flowering plants bloom during the day. It is during these hours that 

they produce the most nectar. It is therefore not surprising that most species 

of bees keep the same schedule. However, there are a few bee species in each 

of the main bee families that become active foragers only at dawn or dusk. 

Naturally they are pollinating plants that bloom at such times. They are called 

matinal or crepuscular bees. In the tropics there are even strictly nocturnal 

bees that navigate by moonlight!

Females and Males

In general, when not working, female bees rest inside their nests. The 

male bees, on the other hand, have nothing to do with nest building or 

provisioning, so they find other places to rest and sleep. Occasionally, it is 

possible to find a cluster of male bees, clinging by their mandibles to flowers, 

stems, or twigs. Male squash and gourd bees are frequently found sleeping 

inside squash blossoms. Look for them in your garden once the sun’s heat 

wilts the squash blossoms. 

Male vs. Female? 

Above: A female digger bee, Centris pallida, 

from the southwestern deserts.

Below: A male of the same species. Note the 

color differences and the slender hind legs of the 

male with no pollen transporting hairs (scopa).
13

Families of Bees

There are 4,000 species of native bees in the United States. The members of the 

five most common families, Apidae, Halictidae, Andrenidae, Megachilidae, and 

Colletidae, can be found throughout the North American continent from Canada 

and Alaska to warm and sunny Florida and Mexico; from forests to deserts; 

from remote wildernesses to gardens and backyards; even the 

National Mall in the heart of our Nation’s capital sports a 

native bee fauna. Perhaps the only places 

where bees are absent are the 

high mountains.

There is even a hardy little bee, the arctic bumble bee, which lives within the 

Arctic Circle. The young queen begins raising her first brood while there is still 

frost on the ground. Sometimes she spends hours vibrating her flight muscles 

while pressed against her brood cells, covering and providing heat for her young. 

She even has a brood patch, a bare spot on her abdomen, to transfer heat to her 

babies, just like many birds do. This physical activity and the heat it produces warm 

the waxen brood cells, speeding the development of the larvae.

Bumble bees and a few other insects are like warm-blooded animals. They can be 

powerhouses producing energy by rapidly flexing their flight muscles. This intense 

effort requires a lot of fuel so they depend upon the early-flowering willows and 

maples to provide plentiful amounts of nectar. Finally, after spending long hours 

taking care of her initial brood, the busy young queen has to leave the nest in 

search of supplies for the family. 

The colorful 

green-eyed male of 

a large carpenter 

bee (Xylocopa 

varipuncta).
14

Apidae (honey bees, bumble bees, carpenter bees, squash 

bees, southeastern blueberry bees, and cuckoo bees)

The family Apidae is the largest bee family and includes a wide variety of 

native bee species, and also the nonnative honey bee. In fact, the name of the 

family comes from the Latin name for the honey bee, Apis. It includes all the 

bumble bees, carpenter bees, and some species of cuckoo bees. Stingless bees 

and orchid bees that are found in the tropics also belong to this family.

Bumble bees

There are about 50 species of North American bumble bees. Many people 

are familiar with bumble bees. They are large, furry, and mostly black with 

stripes of yellow, white, or even bright orange. Bumble bees have some things in 

common with honey bees; they are more sociable than most other native bees, 

forming colonies with one queen and many workers. However, bumble bee 

colonies are never as big or as long lived as those of honey bees. 

Bumble bees are ground nesters with most making their nests in an 

underground cavity or in rare cases, above ground partly covered by thatch. 

The cavities they need for their nests are larger than those of solitary bees, so 

the first thing that a young queen does in the spring is to find an abandoned 

mouse nest or a similar burrow. Then she starts preparing it for her 

brood. She builds a few wax pots that she fills up with pollen and 

 honey, and a larger cell for her brood. Once 

 provisioned the queen lays her eggs, laying no

 more than half a dozen at first. These

 eldest offspring are all sterile female 

workers. Once this brood is 

fully grown, the queen rarely 

leaves the nest again and 

spends all her time laying 

more eggs while the 

workers take care of 

all the activities in 

and out of the nest. 

A female Morrison’s bumble bee (Bombus morrisoni) 

from the western States.
15

The colony grows rapidly, 

and it can reach a population 

of a few hundred workers. The 

workers are usually smaller than 

the queen. It is after her first brood 

emerges that you will seldom observe large 

bumble bees foraging. Near the end of 

the summer, the queen lays male eggs 

in addition to female ones. The females 

emerging at this time become queens, not 

sterile workers, and they soon mate with 

the males after emerging from the nest.

All workers, male bumble bees, and the 

old queen die at the end of summer. The only 

survivors are the new queens, which have already mated. They find a secluded 

hideaway to spend the winter and go to sleep. Then as winter gives way to 

spring and the willows begin to flower, the queens emerge and each will found 

a new colony. 

 Bumble bees and honey bees both have pollen baskets, called corbiculae, 

 on their hind legs. They are more specialized 

 than the pollen baskets of other bees, 

which are called scopae. In honey bees 

and bumble bees, the tibial 

segment of the hind leg is 

flattened, with rows of long, 

strong hairs along the edges. 

The shape of these baskets allows 

them to pack pollen, mixed with some 

nectar and saliva, into a tight mass called a 

corbicular pellet rather than the loose mass of 

pollen grains clinging to the hairs of the scopae 

of other bee species. A few species of bumble bee 

have become cuckoos, laying their eggs in the nests 

of other bumble bees. They have no need for workers 

 or for pollen baskets.

Above: The pale-colored “impatient” bumble bee (Bombus impatiens) from the eastern 

United States. This is the most common bumble used as a pollinator of greenhouse tomatoes.

Below: Female of the rusty-patched bumble bee (Bombus affinis). Populations of this species 

have steeply declined in its eastern and midwestern U.S. habitats.
16

Bumble bees are so 

effective at pollinating 

tomatoes that their buzz 

pollination services are put to 

good use in large greenhouses that 

grow tomatoes year round. All that 

is needed is a queen, a box for the 

nest, and a supply of sugar water because 

tomatoes produce abundant pollen but no 

nectar. The bumble bees are free to come 

and go but remain inside the greenhouse 

most of the time.

Bumble bees and their pollination 

services are a key component in agriculture. 

They are important pollinators of some 

clovers, a forage crop for cattle. 

Carpenter bees

Carpenter bees are typically large and black. You may have trouble telling 

them apart from bumble bees except for one very distinctive feature: 

bumble bees are fuzzy all over, while the upper abdomen of carpenter bees 

is almost hairless, appearing glossy. Early in the spring, males prospect for 

promising courtship and mating sites, not because they plan to set up 

housekeeping, but because they know that such places will 

 attract females. They patrol the 

territory zealously chasing away 

other males that venture 

too close. In fact, 

sometimes they chase 

away almost anything that 

moves, including surprised 

human gardeners. Fortunately, 

they cannot sting (only females have 

stingers), so there is nothing to fear and 

 you can let them be. Females 

have powerful mandibles and use them 

Above: Female of the Yellow-faced bumble 

bee (Bombus vosnesenskii) in flight.

Below: Female of the widespread bumble 

bee Bombus pensylvanicus.
17

to excavate wide tunnel systems in which they build their nests, hence their 

common name of carpenter bee.

Carpenter bees are not always well-behaved pollinators. Occasionally, when 

a flower has a long throat that places the nectar out of reach of its tongue, the 

carpenter bee uses her sharp mouth parts to cut a slit at the base of the flower 

where the nectar is stored. She then drinks the nectar without coming near the 

pollen dispensing anthers or stigma of the flower. Thus, carpenter bees can be 

nectar robbers that cheat the flower instead of doing it a service in return for 

its nectar. Bumble bees are also capable of floral larceny. Look at the trumpet 

honeysuckles, horse mints, or abelias in your garden. You may find the telltale 

signs of these attacks, flowers with their throats slit by thirsty carpenter bees.

Small carpenter bees in the genus Ceratina are related to the larger carpenter 

bees, although you would never mistake them because of the size difference. 

They nest in pithy stems, such as blackberry brambles or roses rather than 

digging their own..

A female large carpenter bee (Xylocopa 

virginica) slits the corolla base of a 

trumpet vine (Tecoma stans) gaining 

access to nectar otherwise unavailable 

with its relatively short mouthparts.
18

Squash bees

Squash bees (Peponapis and Xenoglossa) pollinate flowers of squash, 

pumpkins, melons, and other cucurbits. Peponapis squash bees are 

dependent only on the pollen cucurbits. Squash bees are about

 the same size and brownish coloration of honey bees. You 

can easily tell them apart by their behaviors when they 

are near flowers of these crops. Squash bees are finetuned to the daily rhythms of cucurbit flowers. 

They begin their work shift at or before 

dawn when the flowers of these 

valuable crop plants 

are opening. 
19

They show no hesitation when approaching a squash flower, plunging right 

in, gathering pollen and/or nectar and quickly leaving. Honey bees, on the 

other hand, arrive later in the day once the flowers are past their prime. They 

also take extra time hovering over flowers and visiting them with a slower 

foraging tempo. Even with honey bee hives nearby, it is estimated that squash 

bees do many times more pollination per flower per unit time than honey bees. 

Cucurbit crop growers are very aware of their value as pollinators. These bees 

often nest underground beneath the very plants they will pollinate. If you are 

one of those who pick up your own pumpkin to make a Jack-o-lantern, you will 

be walking over nests full of developing young squash bees.

Females of the common squash bee 

(Peponapis pruinosa) visiting a 

female pumpkin blossom (Cucurbita 

pepo or C. mixta).
20

Southeastern Blueberry Bees

The southeastern blueberry bee (Habropoda laboriosa) gets its common 

name from the fact that it forages primarily on blueberries (Vaccinium spp). Its 

native range is the southeastern United States. Southeastern blueberry bees are 

only active for a few weeks each year. It just so happens that their active season 

coincides with when blueberries are in flower. Compared to honey bees, 

blueberry bees are faster and more efficient pollinators of blueberry flowers. 

The reason for this is that the anthers of the blueberry flower are tubular with 

an opening pore only at one end. The southeastern blueberry bee attaches 

herself to the blueberry flower and vibrates her flight muscles very rapidly. 

Like shaking a salt shaker, pollen comes out of the opening of the anther and is 

collected by the southeastern blueberry bee. When she moves on to the next 

blueberry flower, her buzz pollination not only shakes out the pollen but causes 

pollen clinging to her body to attach to the stigma and pollinates the flower.

Females of the southeastern blueberry bee (Habropoda laboriosa) 

visiting and buzz pollinating the 

flowers of Rabbiteye blueberry 

(Vaccinium virgatum).
21

What is Buzz Pollination or as pollination 

ecologists call it, sonication?

Buzz pollination is the process where 

a bee attaches itself to a flower and 

rapidily vibrates its flight muscles. 

This rapid movement causes 

the entire flower to vibrate and 

loosens the pollen so as to flow out 

the openings in the anthers.

Bumble bees use buzz pollination 

when pollinating tomato flowers. 

Other flowering plants that require 

buzz pollination include cranberries and 

blueberries, eggplants, and other plant 

species in the family Solanaceae. Honey 

bees do not buzz pollinate flowers.

Cuckoo Bees

One large group within the Apidae family, the Nomadinae, is made up 

exclusively of parasitic bees, the cuckoo bees. Nomada bees are usually red or 

yellow, sometimes with whitish markings. They have lost all the adaptations 

that serve to carry pollen as they don’t need to 

provision their young. They are nearly hairless 

and are wasp-like in general appearance. Many 

cuckoo bees parasitize the nests of bees in the family 

Andrenidae. They are often seen in early spring flying 

low over bare ground, searching for the nests 

of potential hosts. Once a cuckoo bee 

locates a nest, she waits nearby ready 

to sneak in and lay an egg while the 

A female digger bee (Melissodes sp.) leaves 

her nest unguarded. A cuckoo bee (Triepeolus 

sp.) waits nearby for the chance to enter and 

lay her own eggs. 

Two female Morrison’s bumble bees (Bombus morrisoni) 

sonicate the pollen from pored-anthers of a garden tomato. 
22

busy female and rightful owner of the nest leaves in search of food. In some 

species of cuckoo bees, the female kills the larva as part of the process of 

parasitizing the nest. The egg of the cuckoo bee develops rapidly and grows 

into a larva that kills and eats the resident host larva in addition to the pollen 

and nectar food reserves inside the host cell.

Megachilidae

This family contains mason bees and leaf-cutter bees. The females use leaves 

and/or mud in their nest construction. Most of these bees nest in holes, either 

in wood or hollow twigs, but there are also a few that nest in the ground. There 

are a few species within this family that are not native to the United States, 

but that have been introduced either intentionally or unintentionally in this 

country. An interesting characteristic of the bees of this family is that they don’t 

carry the pollen on their back legs but on the underside of their abdomens. 

Females of the brightly-colored 

Blue Orchard Bee (Osmia 

lignaria) visit and pollinate 

the blossoms of sweet cherry 

(Prunus avium).
23

If you happen to see a bee, about the size of a honey 

bee, with a yellow belly dusted with pollen, you can be 

sure that it is a megachilid bee (although sometimes 

the color of the pollen it is carrying may be white). 

However, some megachilid bees carry such large 

yellow/orange loads of pollen that they look like 

flying “cheetos” snacks 

coming in for a landing at their nests.

The blue orchard bee, Osmia lignaria, of the 

western United States is being managed for the 

pollination of fruit trees (especially sweet cherries 

and almonds). Farmers are providing drilled boards 

as nesting sites. Already it is proving to be an excellent 

replacement for the beleaguered honey bee on a local, 

though not national, level. Much remains to be learned 

about convenient rearing and use of this beautiful blue bee. 
24

Halictidae (sweat bees)

Some of the most beautiful bees belong to this family. With their shiny 

metallic-colored bodies, these bees will capture your heart. Many are metallic 

green, but others have shades of color from blue to copper or gold, and 

sometimes even black. Most nest in the ground. Some are solitary while others 

share the entrance to their nests. In most cases, that is all they share and are 

not truly social. However, a few sweat bee species go a step further and show 

some division of labor in guarding the entrance to their homes and rearing 

their young. Usually they are sisters that originated from the same nest. Some 

species of sweat bees can be considered truly social; with a division of labor in 

which the mother and founder of the colony lays eggs while the daughters do 

all the other work.

Some unusually attractive halictids (green, yellow and black-striped 

Agapostemon species) are found throughout North America. One of the 

prettiest halictid bees is Augochlora pura (the name means the pure magnificent 

green bee) found in the eastern United States. It has the peculiar habit of 

building her nest under the bark of a rotted log. She takes advantage of the 

A colorful sweat bee, a male 

Augochlorella pomoniella from 

the western States.
25

loose, half-rotted material to make the housing, adding her own saliva and 

secretions to build an envelope for her eggs and accumulated pollen. She 

kneads the pollen into a number of little loaves shaped like tiles, which she then 

plasters on the inner wall of the brood chamber and then lays an egg before 

sealing the cell completely. This precaution is necessary due to foraging ants 

and other predators that abound under loose bark.

One interesting and commercially valuable halictid bee is the alkali bee, 

Nomia melanderi, of the western United States. As its name suggests, the alkali 

bee prefers to build its nest in alkaline soils. It often lives in dense aggregations 

(up to tens or hundreds of thousands of individuals). However, it is not social 

since each female constructs her own burrows and tends to her own brood, 

but lives compatibly with and in close proximity to other alkali bees. The alkali 

bee is a very good pollinator of alfalfa, and some growers take advantage of 

its nesting habits to manage this species to a limited extent. They supply the 

appropriate terrain for the alkali bee’s needs near alfalfa crops. The farmers 

even go so far as creating it artificially by using a tarp, covering it with clay, and 

watering it as needed to create nesting beds. Once established, these alkali bee 

beds can remain active for decades.

There are also some cuckoo bee species in this family, and just like the other 

cuckoo bees, they are almost hairless and somewhat wasp-like. Some have a 

bright red abdomen. 

Another gorgeous 

sweat bee, a male 

Agapostemon 

texanus.
26

Andrenidae (miner bees)

The andrenid bees are all ground nesters and thus the common name miner 

bees. They are mostly dark, black, or reddish, but they can be metallic blue, 

yellow, or red and yellow. They are often shy, medium- to large-sized bees. They 

can be distinguished from other bees by the velvety patches (foveae) on their 

faces, between the eyes and the base of the antennae, though these patches are 

often visible only under a microscope. Many are active only in the early spring. 

The next generation remains underground developing through the summer, 

fall, and winter only to emerge the next spring when their favorite flowers are in 

bloom.

What would eastern forests be without azaleas? Their flowers are one of 

our native flowering plants that honey bees cannot pollinate. They don’t release 

Female andrena (Andrena cornelli) visit an 

eastern Azalea (Rhododendron canescens).
27

their pollen like most flowers, but hold it inside the anthers waiting for a skillful 

bee that knows how to shake it, just like a saltshaker. Further the pollen clumps 

are tied together with sticky threads. Bumble bees and a number of solitary 

bees are good at pollinating azalea flowers. The Cornell azalea bee (Andrena 

cornelli) is one of them, a dark-colored, slender bee that is found in the eastern 

United States. It is never too far from azaleas because their pollen is its favorite 

food. Her pollen baskets have long, widely spaced hairs that are especially 

adapted to the texture and size of these flowers’ pollen clumps.

Andrenids are among the earliest bees to emerge in the spring. You will 

observe them visiting willows, maples, violets, and other early blooming spring 

wildflowers. Some andrenid bees are very good pollinators of apple blossoms. 
28

Colletidae

This is a small family of solitary bees which is considered more primitive 

than other families of bees. Some of them such as the yellow-masked bees, 

Hylaeus, do not have baskets in which to carry pollen. Instead, these bees 

carry pollen inside their crops. They are not as hairy as other bees and can 

easily be mistaken for wasps. They all nest in pithy 

stems. Sometimes they form large 

aggregations of closely spaced nests. They 

use a cellophane-like material exuded from 

glands to line the brood cells where they 

lay their eggs; so sometimes they are called 

cellophane bees.

Bee Mimics

Last but not least, there 

are superb impersonators 

of bees, the flower flies or 

syrphids. Don’t be fooled 

by them. Despite their 

appearance, they are not bees but flies. 

They are frequent flower visitors, and they don’t 

have a stinger like most bees. They masquerade 

as bees to fool hungry birds. 

A male 

yellow-faced 

bee (Hylaeus

sp.) in flight. 

A bee-mimicking 

fly (Eupeodes sp.). 
29

Often they succeed in 

fooling the inexperienced 

observer of bees, as well. 

Bee-flies, another family 

of bee mimics, are parasites of 

many bee species. All flies 

have only one pair of 

wings as compared to 

the two pair of wings 

possessed by bees This is a 

significant difference 

 

between flies and bees, but it is nearly 

impossible to notice when they are 

flying about. Part of the reason for this 

difficulty is that bees’ wings have 

tiny hooks that lock the front and 

hind wings together making them 

appear as just one on each side. 

There are 

several other 

differences 

that would be 

more helpful to the observer of these flower 

visitors. Bee-flies and syrphid flies have 

huge eyes, very short antennae, and 

skinny legs when compared to bees.

Another bee-mimicking 

(possibly bumble 

bee mimic) flower fly 

(Mallota posticata).

A very common garden visitor, the drone fly, Eristalis 

tenax, which looks like the 

European honey bee (Apis 

mellifera).

Another syrphid, or flower fly wasp 

mimic (Heliophilus pendulus).
30

Conservation

In recent years the 

general public has 

become aware that 

honey bees are in 

serious trouble. Honey 

bee colonies have been 

mysteriously dwindling 

in what has been called 

“Colony Collapse 

Disorder.” The cause is 

unknown, but may be due 

to a combination of factors 

including diseases, nutrition, 

stress, and pesticides. This is 

just the most recent of several honey 

bee die-offs over the past century. 

What most people don’t know 

is that it’s not just honey bees 

that are declining. Some native 

bees and other pollinators are 

experiencing population declines 

and range reductions. Many of 

the same factors affecting honey 

bee health are also affecting native bee 

species health as well.

Several bumble bee species on the east and west coasts of the United 

States have been declining precipitously. One hypothesis is that these bees 

may have become infected with a microsporidian fungal parasite from infected 

greenhouse bumble bees used to pollinate hothouse tomatoes that have 

escaped from their greenhouses. In the Pacific Northwest, Franklin’s bumble 

bee appears to be on the verge of extinction. Unfortunately, we know so little 

about most of these bees that it is difficult to fully assess the situation and 

determine the causes for their declines. Buchmann and Nabhan called attention 

to this problem as early as 1996 in their book, The Forgotten Pollinators. They 

emphasized the urgent need to learn more about our native pollinators and to 

take steps toward conserving and sustaining their populations.
31

It may seem strange, but honey bees may be 

contributing to the extinction of some native 

bees. Honey bees can out-compete many native 

bees and extract vast amounts of pollen and 

nectar from every habitat in which they live. 

We can only speculate what the impact of the 

arrival of honey bees has had on the populations 

of native bees in the 400 years since they were 

brought to North America by European 

colonists.

 Habitat loss and fragmentation are 

adversely affecting populations of native 

bees. Pesticides may also have an impact 

on many species including native bees. This 

became dramatically apparent in New Brunswick, 

Canada, years ago when the blueberry crop was 

nearly wiped out despite the fact that the plants appeared 

healthy. 

It was determined that the program to control the 

spruce worm in nearby forests had almost eliminated the 

native bees. Blueberry farmers started litigation that went 

all the way to the Supreme Court of Canada. Eventually, 

they succeeded in having the Government place restrictions 

on the use of pesticides. It took a number of years before the local 

populations of native bees were restored, and blueberry crops became 

plentiful once again.

The situation for all pollinators, but especially managed and native bees in 

the United States, caused sufficient concern that the National Research Council 

of the National Academy of Sciences issued a report titled “Status of Pollinators 

in North America” in October 2006. The document presents evidence of 

downward, long-term trends of the populations of many pollinators, including 

solitary bees and some bumble bee species. However, one of the report’s more 

important findings was that a great deal of additional information is still needed 

to begin to assess population trends and discover their causes.

The National Research Council recommendations include the creation 

of economic incentives for the study of bee populations through a system 

of long-term monitoring and for the development of practices promoting 

pollinator conservation and sustainability. Another recommendation is to 

encourage public land managers and private landowners, including farmers and 

homeowners, to adopt “pollinator-friendly” practices, many of which require 

only a small expenditure to implement.
32

Pollinator Awareness 

A number of government agencies, nongovernmental organizations, and 

private individuals are creating pollinator gardens throughout the country that 

will benefit native bees and other pollinators. The USDA Forest Service, the 

North American Pollinator Protection Campaign, the Pollinator Partnership, 

Urban Bee Gardens at U.C. Berkeley, and the Xerces Society each supply 

information to those who want to start gardening for pollinators or improving 

bee habitat in general.

In Canada, the citizens of Guelph, Ontario, have gone a step further, 

creating the world’s first Pollinator Park 

at the Eastview landfill site. In part, they 

were inspired by the experience with the 

blueberry pollination disaster. They are 

turning an ordinary landfill, about 100 acres, 

into an oasis for bees and other pollinators 

with the right plantings and proper habitat 

for nesting. 

What You Can Do

•	 Plant a pollinator garden. Some 

gardeners are fearful of being stung 

by bees and would rather they were 

not in their gardens. Most native 

bees are quite different from honey 

bees and yellow jackets (which are 

not pollinators) as they rarely sting 

gardeners and if they do, the sting 

tends to be mild. In fact, there are 

some bees, such as the Andrenid 

bees, that are incapable of stinging 

humans because their stingers are too 

small and weak to penetrate their skin.

•	 Avoid pesticides or choose non-chemical solutions to insect problems. 

If you must use a pesticide, read the label and apply and dispose of 

it according to label directions. Where appropriate, consider using 

organic pesticides. For example, aphids can be easily removed by 

spraying them with water from a garden hose. Pesticides can also be 

applied when pollinators are not active, before dawn and at sundown. 
33

As best as you can, try not to apply the pesticide to the flowers. Doing 

so will keep visiting pollinators from sipping contaminated nectar 

or carrying off contaminated pollen. Avoiding the use of pesticides 

may be a reasonable choice in some cases. Nature has its own checks 

and balances and manages to keep most pests under control without 

gardeners having to resort to pesticides. Remember, some damage to 

plants is part of the ecology of your garden. 

•	 Provide a source of pesticide-free water and mud. A dripping faucet, 

mud puddle, or birdbath attracts butterflies and beneficial insects. 

Mud is an important nesting material for some bee species. Providing 

a clean source of water for birds and other pollinators limits their 

exposure to possible toxins in the garden.

•	Plant native plants from your ecoregion. 

Using locally native flowering plants is the 

best gardening you can choose to benefit 

your local pollinators. Native pollinators and 

native plants have become mutually adapted 

through millions of years of partnership 

with one another. Plant-pollinator partners 

exist in your ecoregion. Finding and planting 

the right plants makes a huge difference for 

pollinators. 

•	Provide a variety of native flowering 

trees, shrubs, and wildflowers that bloom 

successively throughout the seasons. 

Fortunately this is exactly what most 

gardeners aspire to have in their gardens. 

Many highly selected cultivars don’t provide 

for the needs of pollinators. In most cases, 

they have lost the floral cues that attract 

pollinators to their flowers. In some cases, 

these improved cultivars no longer produce 

pollen or nectar and as such do not provide 

any food to bees. Using native plants also 

requires less care as they are adapted to local climates. Using native 

plants can be easy on the pocket book. Many modern cultivars and 

nonnative plants such as many of the roses require a great deal of time 

and money to care for them. Think of the flowers your grandmother 

used in her garden as a practical guide, especially when using 

nonnative plants. The pollinators will thank you.
34

•	 You can also plant the kind of lawn that provides habitat beneficial 

to bees. A perfectly manicured, pesticide-saturated lawn is a desert 

to wildlife, including pollinators. Reducing the size of the lawn by 

creating pollinator gardens will benefit native pollinators and other 

species of wildlife. It is possible to have a lawn that is good for native 

bees while being esthetically pleasing. As mentioned before, stay away 

from pesticides and herbicides as much as possible. Second, allow 

some small wildflowers to become part of your lawn. The look of your 

lawn may change as a result, but it will continue to serve its purpose. 

Clover is great food for native bees. It also fixes nitrogen, reducing 

the need for fertilizers. Other small plants that benefit native bees are 

plantago, and veronicas. Rather than calling them weeds, call them 

pollinator food.

•	 Provide nesting habitats for bees. A simple bare spot here and there 

(no mulch or grass, just bare soil) may be enough for an aggregation of 

hard working soil nesting native bees. A sand pile may be even better. 

Standing dead trees are important nesting habitats for 30 percent of 

our native bees. If you cannot tolerate a dead tree on your property, 

it may be possible to keep a stump or a standing log, and use it as 

an attractive planter. Perhaps it will, in turn, provide housing space 

for bees. Drilling holes on an old post or even a tree trunk would 

also make good nesting sites. The holes should be 3/32” to 3/8” in 

diameter (7-8mm) and 4 to 5 inches deep.
35

•	 Build or buy your own bee houses. There are many in the market, and 

it is relatively easy to build your own by following instructions posted 

on several websites. Watching the comings and goings of busy female 

bees can be as much fun as observing a bird house. They become 

watchable wildlife. Hollow paper tubes, just about the size of drinking 

straws, can also be used 

as bee nests. Some of 

the suppliers listed sell 

them. You can also tie 

up a bunch of hollow 

twigs, such as elderberry, 

or paper drinking straws 

together (plastic ones 

are not used by the bees) 

or pack them into a 

container such as a small 

milk carton and place 

them horizontally facing 

south or southeast. They 

should be closed at one 

end (see links at the end 

for instructions). Gluing 

the straws at their back 

ends into your container 

is helpful.
36

Conclusions

Helping native bees is essential to our continued survival, health, and 

well-being. These animals benefit us all because of the invaluable ecosystem 

services they provide to the environment and to our farms, forests, and 

gardens. Not only do they pollinate most of our flowering plants, their bodies 

feed other wildlife and their ground-nesting behaviors aerate and enrich 

soils. They enrich and sustain our lives. The observation of native bees can 

become a lifelong pastime and pleasure. Become involved. Observe bees with 

close focusing binoculars; plant a small pollinator garden; or help a neighbor, 

student, or family member drill small holes in scrap lumber to create a bee 
37

house. Join a pollinator and plant-friendly organization to learn more about 

pollinators and their flowers, like the Pollinator Partnership (www.pollinator.

org). Become a pollinator observer as a citizen scientist and report your 

observations. Some of our bees are declining, and your findings are invaluable 

to understanding the big picture. Most importantly, get outdoors with your 

children and experience the amazing natural and urban habitats that we share 

with pollinators and flowering plants. Do your share to make sure that this 

precious legacy continues. 
38

Resources

• http://www.pollinator.org – Bee articles, planting and gardening guides

• http://www.fs.fed.us/wildflowers/pollinators - one of the Web’s most 

informative sites concerning pollinators.

• http://www.nature.berkeley.edu/urbanbeegardens/ Urban Bee Gardens. 

Berkeley University.

• http://www.nwf.org/gardenforwildlife/beehouse.cfm Bee houses. 

National Wildlife Federation. (How to build a bee house)

• Attracting Native Pollinators. 2003. The Xerces Society and The Bee 

Works. Portland, Oregon. (Bee gardens, bee houses, etc.)

Sellers of bee houses

• http://www.knoxcellars.com/ Knox Cellars. 

• http://www.masonbeehomes.com/index.php Mason bee homes.

Additional readings

• Buchmann, Stephen L., Nabhan, Gary Paul. 1997. The Forgotten 

Pollinators. Island Press, Washington, DC, Covelo, CA, ISBN 1-55963-

353-0. 292 pp.

• Mader, Eric, Spivak, Marla and Evans, Elaine. 2010. Managing Alternative 

Pollinators: A Handbook for Beekeepers, Growers and Conservationists. 

SARE Handbook No. 11, NRAES-186. Natural Resource, Agriculture 

and Engineering Services (NRAES), Cooperative Extension, Cornell 

University, Ithaca, NY. 162 pp.

• Packer, Laurence. 2010. Keeping the Bees: Why All Bees Are At Risk 

and What We Can Do to Save Them. Harper Collins Publishers LTD., 

Toronto, Canada. 273 pp.

Bee families, description, classification
39

• O’Toole, Christopher, Raw, Anthony. 1999. Bees of the world. Cassell 

Illustrated. ISBN 0-8160-5712-5.

• http://www.umext.maine.edu/onlinepubs/htmpubs/7153.htm

Understanding Native Bees, the Great Pollinators. University of Maine 

Cooperative Extension. Bulletin #7153

• http://www.everythingabout.net/articles/biology/animals/arthropods/

insects/bees/ Everything About Bees. Everythingabout.net

• http://www.gnb.ca/0171/10/0171100025-e.asp Native Bees that 

Pollinate Wild Blueberries. (Families that pollinate blueberries; nests, etc.) 

Department of Agriculture and Aquaculture of Canada. New Brunswick

• http://www.greatsunflower.org/ The Great Sunflower Project. 

(Information on bee families).

Conservation

• http://dels.nas.edu/dels/rpt_briefs/pollinators_brief_final.pdf Status of 

Pollinators in North America. The National Academies.

• http://nappc.org/pollinatorEn.html North American Pollinator 

Protection Campaign

• http://www.pollinator.org – Useful resources page has 20 bee articles.

• http://www.xerces.org/wp-content/uploads/2009/01/how_to_protect_

native_bees.pdf Native Pollinators. How to Protect and Enhance Habitat 

for Native Bees.
40

Photo Credits

p. 30-31, carpenter bee (Xylocopa virginica) on rose (Rosa sp.) 

 by Teresa Prendusi

p. 32-33, women in native plant pollinator garden by Laura Christman

p. 34, megachilid bee (Megachile sp.) on blanket flower (Gaillardia sp.) 

 by Jim McCulloch

p. 35, bee house created by Beatriz Moisset 

p. 36, a bumble bee (Bombus sp.) on purple coneflower (Echinacea

 purpurea) by Teresa Prendusi


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FS-960 Reprinted March 2011
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