Base tray holds about 2000 cocoons



Two trays are held in place with duct tape.

Two trays offset to create a 1/4″ gap.



Mass release of alfalfa leaf cutter bee cocoons.

I started this article some time ago, before I had all the pictures in place.  Even though most mason bees have been set out, I think it is good to compare mason bee release systems to the commercial Alfalfa Leaf cutter bee industry mas  release system.  I think we can learn a lot from the 50 year old alfalfa leaf cutter bee industry.

How to set out bees, still in their cocoons, depends on quantity of cocoons, type of nests and whether predators exist in the area.

Leaf cutter bee nests

Alfalfa leaf cutter bee producers in the Canadian Prairies, usually mass release leaf cutter bee cocoons on trays.  Thousands of cocoons are placed on trays.  Trays are set up inside yurts or similar structures that house leafcutter bee nests. Three weeks prior to setting cocoons out, leafcutter bees are put through a warming period so that bee emergence is relatively fast.  Trays are out for less than a week.  A mere 7 days or so is little time for winds and predators to upset the trays full of cocoons.

Prairie yurt with a tray of cocoons set on top of nests.

It is a different story with mason bees.  Emergence is often longer than a week, especially under cool spring temperatures.  The number of cocoons set out are often  less than a hundred or several hundred and less often in the thousands.

Setting out a few cocoons (less than 100) small vials with a bee size hole in the lid works well.  Plastic vials are usually rodent proof.  The space underneath the roof of the Beediverse Highrise  is a great place to place the vial full of cocoons.  This space is protected from the sun, but receives the heat through the roof.

the Highrise roof protects vials of cocoons from predation and sun.

Beediverse Emergence box protects cocoons from predation and the elements.

When setting out 100 or more cocoons, small vials are too cumbersome and too time consuming.  It would be very easy to set out cocoons in open trays.  I have tried setting cocoons out in trays, even in covered trays, but it has been less successful.  Their extended emergence becomes problematic.  Winds sometimes tip trays onto the ground  Trays also make cocoons more vulnerable to predation from animals such as spiders, squirrels, mice, and wasps.  To decrease the chance of predation a wooden box with an exit hole such as the Beediverse Emergence Shelters gives the best result.  Two are sold for $19.95.

Small and large release boxes. Dave M.  Port Alberni BC

I find these extremely handy.  I fit about 200 cocoons into each one.  I make notes on the outside to tell me where cocoons were produced.  This is handy because after spring emergence, I can check what the emergence was the previous spring.  Emergence should be 95% or more.

David M. from Port Alberni uses a square box with a hinged lid.  Each box, with two layers of cocoons, holds about 2000 cocoons.

If you have a system you would like to share with our readers, email me a description and pictures.

Starter Cottages, available from my on-line Beediverse.com web site, are by far the best little box for use as a release box/emergence box.  I have tried all kinds of boxes, made from cardboard, plastic and wood.  Cardboard is too fragile and predators can get at the cocoons too easily.  Plastic sometimes overheats and is slippery for the bees to walk on while exiting.  Starter cottages are bee proof, can be washed for next year, and are relatively predator proof.  I usually place 100-200 cocoons per cottage.  One day before setting the cottage out into the field and adjacent to nests, I set the cottage out in the kitchen table. It gives the bees a head start on emergence.  I don’t want bees to fly around my kitchen, so I need a bee proof container= Starter Cottage.

I used this plastic container to carry 5 Starter cottages to the field site.   Each has about 100 cocoons.  The door to the cottage is secured with a pin, sometimes two.  The entrance hole is temporarily plugged with a cardboard straw until the starter cottages are set up in the yurt or other structure.  These Cottages have been out of the fridge and into a kitchen environment for 24 hours.  This means that some of the males will have emerged.

The D27 Yurt is set up with 9 Highrises in the upper part of the yurt.  Each Highrise has Eco-Corn Quicklock nesting trays with 72 nesting holes.  Note these Highrises do not have a cedar roof.

Starter cottages are set on top of each Highrise.
This is a Charly- Yurt containing many different
nesting trays, wood, plastic and eco-corn.

Once Starter cottages have been set in place,
the cardboard tube is removed.
Three males have emerged and are examining their new abode.   Note their long antennae- nearly as
long as their wings.
They now have to wait for the girls to appear.

The reason for setting out cocoons within the protection of a house that shelters nesting tunnels, is to provide the cocoons, and the mason bees inside, a place that is protected from predators like mice, protected from the sun and protected from rain and snow.

Royal house with predator guard

Temporarily remove predator guard from the front of the Royal house, and set vial on its side, with tab removed,  underneath peaked roof.  Replace predator guard.

Lodge without predator guard.

Chalet with predator guard.

Unwrap bundle of nesting trays by removing electricians tape.  Remove one set of trays, and re-tape remaining nesting trays. The vial can now be inserted under the roof and adjacent to the nesting tunnels.

Replace the predator guard of the Chalet after vial has been set inside the house.  When all bees have emerged- about 2 weeks after first bees emerge, remove vial, tape up the individual tray  and set above other trays.