Identify Types of Bees: The Osmia Mason Bee

Bees of the Osmia genus are frequently called “Mason Bees,” and they’re most common in the western United States. They differ from other types of bees because of their unusual nesting habits.

  • Osmia females carry dry pollen in a patch of hairs (scopa) on the underside of the abdomen, a feature they share in common with other females in the family Megachilidae.
    Photo By Rollin Coville
  • Bees, wasps, butterflies, moths, flies and some beetles pollinate more than 70 percent of flowering plants, but North America's native pollinators face multiple threats to their health and habitat. In "Attracting Native Pollinators," the Xerces Society offers a complete action plan for protecting these industrious animals by providing flowering habitat and nesting sites while also providing specifics for identifying types of bees and other pollinating insects.
    Cover Courtesy Storey Publishing

The Xerces Society, a nonprofit conservation organization, is a leader in the effort to conserve North America's native pollinators. Founded in 1971, the society protects insects and other invertebrates through advocacy, education, policy development and applied research projects aimed at protecting and managing critical habitat. Attracting Native Pollinators (Storey Publishing 2011), by The Xerces Society, is a complete action plan and information guide for protecting bees, wasps, butterflies, moths, flies and some beetles by providing flowering habitat and nesting sites.The following excerpt comes from Part 3: Bees of North America.

You can purchase this book from the MOTHER EARTH NEWS store: Attracting Native Pollinators

Osmia: Mason Bees


FAMILY: Megachilidae

SUBFAMILY: Megachilinae

Osmia are usually called Mason Bees because many of these types of bees construct walls of mud to divide the nest cavity into brood cells. The genus is large, with approximately 150 species in North America. Many species are widespread and abundant, but Osmia are rare in deserts. They are most common in the western United States; east of the Mississippi, there are only 27 species.

4/26/2018 1:46:35 PM

It is worth mentioning that there are two introduced species of Osmia. The Japanese one, O. cornifrons, and the Asian, O. taurus. They are becoming increasingly widespread and abundant. For instance, these two species combined account for 18% of all the Osmia sightings reported in Bugguide ( Granted that this is not a scientific statistics but it is a gross indication of how common these introduced species are, specially when you consider that there are about 150 native species in the genus.

Subscribe Today - Pay Now & Save 64% Off the Cover Price

50 Years of Money-Saving Tips!

Mother Earth NewsAt MOTHER EARTH NEWS for 50 years and counting, we are dedicated to conserving our planet's natural resources while helping you conserve your financial resources. You'll find tips for slashing heating bills, growing fresh, natural produce at home, and more. That's why we want you to save money and trees by subscribing through our earth-friendly automatic renewal savings plan. By paying with a credit card, you save an additional $5 and get 6 issues of MOTHER EARTH NEWS for only $12.95 (USA only).

You may also use the Bill Me option and pay $17.95 for 6 issues.

Canadian Subscribers - Click Here
International Subscribers - Click Here
Canadian subscriptions: 1 year (includes postage & GST).

Facebook Pinterest Instagram YouTube Twitter flipboard

Free Product Information Classifieds Newsletters