Cocoons in the Fridge: The Mason Bee Diaries

Our second fridge in the basement is filled with extra beer, surplus groceries, and mason bee cocoons.  But if you’ve ever come over for dinner, don’t worry.  We didn’t sprinkle cocoons in your salad.

No, as soon as the warm spring weather arrives, we’ll put the cocoons back outside to hatch in their bee house, oblivious to the fact that they spent the winter in our fridge.

How It Began

A few years ago, while Chris and I were relaxing on our porch bench, we noticed that a mellow little flying insect was quietly investigating the bench. Eventually it lost interest and moved on.

We wondered if it was an insect we should be worried about. But with a little research we learned that it was an orchard mason bee.

We’d never noticed one in our garden before, but now that we knew they were there, we decided to help them.  We started with some light reading, and then we set up a bee house for nesting.  We bought a few mason bee cocoons to add to the existing population.

Who could resist this face?

An orchard mason bee

Understanding the Orchard Mason Bee

I used to think of bees and beekeeping in terms of hives, honey, queens, protective clothing, angry swarms, and running.  But these things are all associated with the honey bee.

Solitary Bees

Orchard mason bees are native to North America.  They are sometimes called spring bees or just mason bees.

They are considered solitary bees because they don’t have the social structure that honey bees have.  They don’t live in a hive and they don’t produce honey.

Mellow

Because they don’t have a queen to protect, mason bees are more easygoing than honey bees.  They have no interest in messing us up, and they rarely sting.

Spring Pollinators

Various species of orchard mason bees are found in most climates where fruit trees grow.

They go about the simple business of finding a safe place to deposit their eggs and ensure their eggs’ survival.  They work hard at this.  And, in the process, they are excellent spring pollinators.

They hatch right about the time the fruit trees blossom.  So when our bees have a good year, we have larger harvests of plums, apples, and pears.

Life Cycle

In spring, when temperatures have reached around 55ºF, mason bees begin to hatch from their cocoons.  They need sun to fly, and they usually warm up for a while before testing their wings for the first time.

orchard mason bee

I was disappointed that I was at work then our first-ever batch of bees began to hatch and emerge from the bee house.  Chris was home to see it and left me a voice mail saying “Our bees are hatching!”

I imagined him, phone in hand, standing amidst a lively swarm.  But it’s not like that.  They emerge gradually over several days, and if you’re not watching at the right moment, you won’t see anything.

A mason bee emerges from a bee house

An orchard mason bee emerging

They mate, and then the female does all the heavy lifting.  She seeks out a nesting spot for her eggs.  She does not drill holes, but rather she looks for preexisting holes of the right diameter and depth.

In our garden, she has a choice of using either a wooden nesting block

Orchard Mason Bee nesting block

or nesting tubes.

Nesting tubes for orchard mason bees

Once she finds a suitable location, the work begins.

Living up to her name, she builds a mud plug at the back end of the tube. Then she gathers pollen and nectar and deposits it inside the tube, at the back.  She lays an egg on top of the pollen and nectar mixture.  Then she builds a mud wall to seal in the egg, creating a protective chamber.

In front of that wall, she deposits more pollen and nectar and another egg and creates another wall, working her way up the length of the tube until she has filled the tube with these egg chambers.

Later the eggs hatch, become larvae, and slowly eat the pollen and nectar left by their mother.  Then the larvae spin protective cocoons where they mature into bees.

This photo, taken during our fall cocoon harvest, shows a couple of cocoons in their masonry chambers.

Orchard Mason Bee cocoons

What happened to their hardworking mom?  Adult bees usually expire by June.  There is no retirement plan for the orchard mason bee.

But the cycle continues because, providing they don’t fall prey to invasive insects, extreme weather, and other hazards, the cocoons will hatch the following spring, and the process will start again.

Helping the Orchard Mason Bee Succeed

We’ve seen firsthand how hard these bees work to ensure that their offspring survive.  But adverse conditions can spell disaster.

Staying Informed

There is only so much we have control over, but we do everything we can to help them succeed. We had been reading from various sources and trying different things.

Then, about a year ago, we found a very helpful resource:  Crown Bees’ “BeeMail” Newsletters. These email reminders tell us what to do for our bees and when to do it.  They also keep us current on any new bee-related innovations.

What a Mason Bee Wants

Caring for orchard mason bees is relatively easy and not very time-consuming. Months can go by where we take little or no action.

Before the new bee season starts, we replace used nesting tubes with new ones, and some years we purchase cocoons to add to the existing population.

Natural Nesting Reeds and Cocoons

Orchard Mason Bee Nesting Tubes

Orchard Mason Bee cocoons

Then, since mason bees don’t stray far from their nesting sites, we just try to make sure they have everything they need nearby: Bee houses in the right location, access to right kind of mud, fresh water, and of course flowering trees and shrubs nearby.

Even the smallest things help, like providing a shallow water bowl with pebbles so the bees can get water without drowning.

Orchard mason bee water bowl

And in fall, we (and by “we,” I mean Chris) harvest the cocoons, put them in a cocoon humidifier, and store them in the fridge until spring.

Harvested Mason Bee Cocoons

Orchard Mason Bee cocoons

Storing the cocoons in the fridge keeps them dormant while protecting them from harsh winter weather and extreme temperatures.

How Our Bees Did Last Year

Every year is different, but 2016 was a good year.  We placed the cocoons outside on April 1st – 68 that we’d overwintered in the fridge, and 30 that we’d newly purchased.

Over the course of several days, all but one hatched. And the cycle of mating and laying eggs began.

We tried something new in summer, once all the adult bees were gone:  We placed protective bags around the nesting sites to keep invasive insects away.

When we harvested the new cocoons in fall, we had approximately 150 cocoons – a 50% increase over what we started with in spring.

In this photo, you can see which nesting tubes were  filled with cocoons and sealed with a mud plug.

Orchard Mason bee nesting tubes

Our Plan for This Year

We are constantly improving our methods.  The bees seem to favor the natural reed nesting tubes, so this year we will be using more of them.  We are thinking of adding another bee house in a different location to see how it does.

But one thing never changes:  Mason bee season is always fun.

A warm thank you to Crown Bees for providing supplies for this post.  All opinions expressed are my own.


This post is for entertainment only and is not a tutorial. Mason bees are not suitable to all climates.


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10 thoughts on “Cocoons in the Fridge: The Mason Bee Diaries”

    1. Loralee, that’s a great idea. I think mason bees would be the perfect complement to rain gardens. It’s so gratifying to care for these bees. I hope your clients enjoy it as much as we do!

  1. Mason bees are just the thing to encourage now that the honey bees that lived in the outer corner of my house has died out. I may have even seen some around.
    Thanks for this informative blog.

    1. Glad you enjoyed the post, Peggy! Even if your honey bees make a comeback, I don’t think they will mind the orchard mason bees being there. The mason bees will be gone by June – right around the time the honeybees are in full swing.

  2. For years I’ve been saying I wanted to do this and even a few years ago I scored many bee tubes but have yet to put them out. Now is the time, thanks for the reminder and the motivation, and thanks for linking up with us at Waste Not Wednesday!

    1. Toni, thanks for hosting Waste Not Wednesday. Good luck with your beekeeping! We really enjoy it and even feel very protective of “our” bees.

  3. This is so interesting! I don’t think I realized the difference between a honey bee and a mason bee. I have lots of bees in my garden during spring and summer. I’m going to have to pay close attention. Thanks for sharing with SYC.
    hugs,
    Jann

  4. Heidi, you never cease to amaze me with the things you and your husband accomplish. I had never heard of mason bees. Your post is so informative and interesting. Best of luck with bees this year. Thank you for sharing your experience with mason bees at the Snickerdoodle Create~Bake~Make link party!

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