What you need to know about Bees

Hundreds of North American native bee species are sliding towards extinction

The widespread decline of European honey bees has been well documented in recent years. But until now much less has been revealed about the 4,337 native bee species in North America and Hawaii. These mostly solitary ground-nesting bees play a crucial ecological role by pollinating wild plants and provide more than $3 billion in fruit-pollination services each year in the United States.
— Center for Biological Diversity, March 2017
Pollinators in Peril: A systematic status review of North American and Hawaiian native bees

Of the native species studied by the Center for Biological Diversity (1,437), more than half (749) are declining.

According to the 2017 report, of the native species studied nearly 1 in 4 (347 native bee species) is imperiled and at risk of extinction.

Learn About Bees

Knowing about bees is important to helping them thrive.

Americans appear to be very aware of the decline of honey bees. One reported response has been an increase in urban and suburban beekeeping in the last decade.

Less known is that hundreds of North America’s 4,000+ native bee species, including many American bumble bees, are moving towards extinction. 

Bees that live communally, including honey bees and some bumble bees, represent only 10% of bee species. In communal species, the queen bee lays all the eggs.

Ninety percent of bee species are solitary. Of those, 70 percent live underground, 30 percent above ground. Each solitary female bee lays eggs. She builds her own nest, stocks it with food for her offspring, lays her egg, and seals it safely in with the provisions to emerge as a full-grown bee the next season.

Native bee species are central to their regional ecosystems and often particular species are tied to specific native plants that depend on the bees for their reproduction.  In addition, native bees provide more than $3 billion in fruit-pollination services each year in the United States.

[https://theconversation.com/beyond-honey-bees-wild-bees-are-also-key-pollinators-and-some-species-are-disappearing-89214]

Bees and Flowers

Bees and flowers evolved together.

Bees and flowers have evolved together for millions of years. In their mutual relationship, the bee receives food (nectar or pollen) and the stationary plant gets to disperse its pollen (sperm cells) to other plants of the same species. Because this is much more efficient than wind pollination, over millions of years plants developed flowers with increasingly specialized features to attract visiting bees who, in turn, distribute pollen, optimizing the plant’s reproductive potential. In chorus, bees underwent co-evolutionary adaptations to take advantage of the nutritional benefits offered by flowering plants.

Bees and Humans

Beekeeping developed independently everywhere there were honey-producing bees. Bee tending began in Africa about 10,000 years ago.

A Mesolithic rock painting shown to the right depicts a honey hunter harvesting honey and wax from a bee nest in a tree. Even 2,500 years ago, ancient Egyptians practiced beekeeping similar to modern methods.

The ancient Maya first domesticated a species of stingless bees. And they are kept in Central America today. Their culture is referred to as meliponiculture, named after Meliponini bees found in tropical and sub-tropical America.

In Australia also, stingless bees were kept traditionally, and still are, for production of their highly prized honey, which is markedly different and less abundant than honey of European honey bees apis millifera.

Bees Worldwide

There are over 20,000 named bee species, with an estimated 20,000 more yet to be identified and described.

North America has 4,000 species with an estimated additional 1,000 yet to be identified. Of these 1,600 species are native to California.

Bees and Our Food Supply

According to the USDA, bees pollinate about 80% of flowering plants and about 75% of the nuts, fruits, and vegetables Americans eat. At least one in three bites of food depends on bees and many common crops would not exist without bees: melons, almonds, zucchini and many others. In addition, many livestock feed plants (i.e. alfalfa) need bee pollination.

Honey bee pollination is worth $20 billion annually to U.S. crop production and worldwide $217 billion. 

What Bees Need

For bees to thrive it’s necessary for them to have access to the following 5 conditions.

A Gallery of Bees

To provide forage and nesting support for bees, learn the varieties of bees and their needs. This gallery provides a broad and incomplete overview of the varied species. (Scientific terms are defined the first time they are used.)

If you are interested in learning more about identifying bees, we recommend I Spy! Who's Using My Garden? by Katy Pye. This practical step-by-step workbook combines tools with a roadmap to help you identify and track which pollinators work in your garden now and after changes and which plants and other features are most important to them.

I Spy! Who's Using My Garden? is a great partner for your favorite pollinator identification guide. For California bees, we recommend Field Guide to the Common Bees of California by Gretchen LeBuhn and Noel B. Pugh.

Bee Families

Bees are classified as a monophyletic group (from one ancestor) within the superfamily Apoidea, which includes some wasps. Over 20,000 named species of bees are in seven biological families.

Andrenidae

Over 2,000 species, known as mining bees, found nearly worldwide particularly in temperate or arid areas; solitary, ground-nesters.

Apidae

Nearly 6,000 species, includes bumble bees, honey bees, stingless bees, carpenter bees, also parasitic cuckoo bees; some found worldwide, stingless bees in South America and Australia; honey bees spread worldwide by humans; many social, or eusocial (highest level of insect organization, with reproductive castes, specialized tasks and cooperative care of the young), most are cavity dwellers.

Colletidae

Over 2,000 species, known as plasterer bees for lining their nests with secretions that waterproof the walls; primarily found in South America and Australia, most are solitary ground nesters, some above ground nesters.

Halictidae

Over 2,000 species, called sweat bees as some are attracted to perspiration, many are metallic in appearance, some are green; found worldwide; most nest underground; most are solitary, some communal, semi-social or eusocial.

Megachilidae

Over 4,000 species, commonly named by materials they use in their nests: mason bees, leafcutter bees, carder bees, who use soil, leaves, and fibers, respectively, includes several species of parasitic cuckoo bees; found worldwide, mostly solitary, above ground nesters.

Melittidae

More than 200 species, with oligolectic foraging habits (specializing in a single genus of flowering plants, or more narrowly in a single species), found primarily in Africa; solitary, ground nesters.

Stenotritidae

Only 21 species restricted to Australia; ground nesting.

Above Ground Nesting Bees

About 30% of North American native bees nest Above Ground in wood tunnels or hollow stems.