Numbers
Approximately 20,000 species worldwide; 4,000 in the US
Identification
Pronotum short, collarlike. Body usually very hairy. A distinctive feature of bees is that their hairs (at least some of them, particularly on the thorax) are branched or plumose; while those of wasps are simple. The hairs of bees collect pollen that they periodically brush and store on pollen transporting apparatus, brushes of hairs on the abdomen of Megachilidae or on basket like structures on the hind tibia, as in the honey bee.
The bees that lay their eggs in other bees' nests, “cuckoo bees", look wasplike; they have less hair and lack pollen transporting apparatus.
OVERVIEW OF FAMILIES
Family Andrenidae - Mining Bees
Family Apidae - Cuckoo, Carpenter, Digger, Bumble, and Honey Bees
Family Colletidae - Plasterer Bees, Masked or Yellow-faced Bees
Family Halictidae - Sweat Bees
Family Megachilidae - Leaf-cutter bees, Mason Bees, and allies
Family Melittidae - Melittid Bees
Range
Worldwide, except polar regions.
Food
Primarily nectar and pollen from flowers.
Remarks
Pollen collecting bees are extremely important for the pollination of plants, including many crops such as most fruits and vegetables. Their pollinating services in the U. S. Have been estimated in the millions of dollars. Not only honey bees but many other species of bees play this role.
Honey bees and bumble bees are highly social; their colonies consist of a queen, workers and drones. Some halictid bees are primitively social.
