Just Another Nature Enthusiast

JANE’s Images & Thoughts 🌲 Inspired by the Pacific Northwest & places I wander

Mason Bee 101

Mason Bee 101

Are these questions you would ask?

Imagine walking along a nature trail. The shelter where you plan to eat lunch is easily recognized.

But you wonder…”What are those three boxes mounted on the poles?”


Hike around the bend in the path, a new perspective of the structures comes into view.

But, still, the question comes to mind-

“What are those three boxes mounted on the poles?”

Most of the time, boxes on poles are constructed to be some type of bird house. Assuming that the structures are bird houses of some kind…

Wire netting on the fronts seems a bit curious.

“If those are bird houses, how do the birds get in and out?”


An important clue along the way may have been overlooked.

Notice where the boxes are located.

There… in the middle of a field full of wild flowers.


The purpose of the three boxes mounted on poles becomes clear.

They are nesting stations for native pollinators. Located along the nature trail at Jackson Bottom Wetland in Hillsboro, Oregon.

These don’t look like the beehives normally associated with bee colonies. A look inside the structures inspires another question.

“Why are there little boxes and trays?”

A nearby information box reveals that the nesting stations are made specifically for Mason Bees.

“What are Mason Bees?”

Asking questions about bees is a good thing to do anytime, but especially during National Pollinator Week.

Finding answers is a fascinating learning experience. As my husband and I discovered by attending a class presented by the expert who built the pollination stations and monitors them-  Master Gardener, Ron Spendal.

His presentation, “Mason Bees: 101,” helped us to understand the life cycle, nesting habits, and management of mason bees.

Unlike the eusocial organization of honeybees, where life in a hive involves many individuals, each, with specific roles and tasks to perform, Mason Bees are solitary bees. The lone female pretty much does it all. Males perform mating duties early in the spring and then die.


That is the reason why the boxes do not look like the bee hives normally associated with honeybees.


Ron explained that  the little trays in the stations provide nesting sites for female bees. Because Mason Bees are gregarious, they don’t mind living near each other. Each female maintains her own “hole” or channel in the tray. When one is completed, she will begin another.


A female Mason Bee works fervently during her 6-8 week lifespan.  She will make close to 2,000 flower contacts to produce one pea-sized pollen pile to support an egg. The process will occur for each of the 30 or so eggs a single Mason Bee female will lay during her lifetime. That’s A LOT of pollination… it takes 30,000 Honey Bees to do what 250 Mason Bees can do when it comes to pollinating a single acre of flowers.

She will gather pollen and nectar for a pollen pile, lay an egg, and then seal that chamber with a bit of gathered mud she also collects. As she lays her eggs, the female predetermines the sex of each, and lays the females towards the back of the chamber with males at the front. In the spring, males emerge first, ready to perform their sole purpose in life- to mate with the females when they emerge a short time later.

Because Ron builds his trays with plexiglass covers, he is able to observe the life-cycle processes and record important data about Mason Bees. The slides in his presentation allowed him to share the marvel of metamorphosis from egg stage to emerging bees.

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We learned about some of the challenges Mason Bees face… including Chaetodactylus, commonly known as the pollen mite; Monodontemerous or  Parasite wasps;  and birds, squirrels, rodents.

Ron described steps to combat each- including how to clean chambers, and scour cocoons to eradicate little pests; and put up hardware cloth in front of the boxes to keep out big pests.

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Ron Spendal’s knowledge is as vast as the numbers of flower visits each female must make to support the eggs see lays each season. If every community had a bee expert like him, people would better understand and appreciate the roles these insects play in food production and life-support on Earth. For humans alone, every one in three mouthfuls we consume comes from a pollen-dependent crop. Ron interweaves his thoughts about bee ethics in our industrialized agricultural world, and the need for awareness/problem-solving bee colony collapse with facts about lifecycle and bee raising.

If you live in the Portland, Oregon metro area  and would like to attend one of his classes, Ron will present another Mason Bee 101 class on Saturday, August 8, 2015 at 10:00 am. In the Garden Series, Learning Garden at Jenkins Estate, 8005 SW Grabhorn, Beaverton, OR. He will also teach a Native Pollinators Class on Saturday, August 15, 2015 –
10:00am to 11:30am. Jackson Bottom Wetlands Education Center, Hillsboro, OR.

First in a series of posts for Pollinator Week


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