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Friday, January 28, 2011

Wasp predators found in Escape/Emergence boxes

Note escape hole of box in foreground and the escape hole in the adjacent box.  Mason bee cocoons cover the base of the box waiting for warm spring temperatures. As the temperature increases, bees chew their way out of their cocoon and then travel towards the light of  the exit hole.  Note empty cocoons.  Dave uses a hinged lid for closing the box.

Female wasps overwintering in an escape box (emergence box).  If left inside box, wasps would eat bees as bees emerge from their cocoons.

Hi Margriet: Look what I had waiting for me when I went to clean out the escape boxes from last year.
Dave M.Port Alberni, BC Canada

Mason bees use an umbrella as a nest site!

Hi Margriet: Here's a couple of pics I took today. The umbrella had been hanging on the back porch since spring. Nothing is safe around here. I got 6 cocoons and all are good. (4 females, 2 males).  Dave M.  Port Alberni, BC Canada

Thursday, January 27, 2011

Mason bees use a two foot long nesting tunnel.

Two feet long tunnel filled up to the 19 inch mark!
A long nesting tunnel  for a mason bee

 Hi Margriet, Well they have gone and done it again. You know that 8ft long escape box (emergence box or shelter), well I was cleaning it up for this season and noticed one of the escape runners looked plugged so I decided to take it apart to clean it. This is what I found. What do you think?  Dave  M. from Port Alberni, Vancouver Island, British Columbia.
I have not seen this before, but I am not surprised.  As in your photos (see recent blogs), mason bees will nest in any type of 'cavity' (umbrella for example)!  Thank you for sending the photos.  Margriet

Mason bees in Turkey?

Peter B. from Ankara, Turkey emailed me the following question:

"Your fascinating website was sent to me by Chris K. I have looked at it plus several others.  I am a beginner, but would like to try raising some mason bees as a hobby.
I am from Vancouver, but living most of the last 10 years in Ankara, Turkey.  I would like to try manufacturing a house for mason bees here in Ankara.  A few quick questions for you:
1. Ankara is a big city (5,000,000) and at almost 1000 m elevation.  We are some distance away from the downtown, there are some large city parks near us, but we are still in the city.  Do you think there are any mason bees that we could attract here in Ankara?
2. I understand that the species is different for the mason bees here.  For the house, is 8 mm diameter OK, or do they require a larger or small diameter hole?  Is there anything else that would be much different from the North American mason bees in terms of housing or rearing requirements?
Thanks in advance,   Regards,  Peter B."

Yes, the species found in Turkey are different to the ones found on the North American continent, although their lifecycles would be similar to the ones found in NA.  If the early spring mason bee exist in Turkey, it would be Osmia cornuta.  The 7.5 mm or 8mm would be a good hole diameter to use for your nests.

If you are interested in seeing what solitary bee species exist in the area, make 2 or 3 different nest diameters.  Local gardens with flowering plants would provide bees with pollen and nectar for themselves and their offspring.  The nesting hole diameter I would recommend are: 3mm 5mm and 7.5mm.  This gives you a good range of nesting tunnel sizes.   Make nests by routering flat pieces of wood.  These pieces are stacked and allow nests to be opened up in the fall.  This makes it all the more interesting than just seeing the plug at the end of the nesting tunnel.  Good luck, and let us know what you find.

Friday, January 21, 2011

Yurt 2010 -Cherry and Apple Blossoms

A beautiful cherry tree in full bloom.  Something to look forward to!

 I have one of the yurts on this property.  The neighbours came over and asked the owner of the property what that funny blue structure was in his yard.  Not even the bees on the wall gave them a clue that this was our newest yurt!  The bees love it.  I love it.  No worries about wind or rain.  Lots of warmth inside the yurt to keep the larva warm during the day.
The Yurt was placed in a sunny spot away from trees or buildings that might throw a shadow on it.

Apple trees in full bloom with yurt in the centre of the picture, behind the trees.

Thursday, January 20, 2011

Eco-Corn Quicklock trays houses summer solitary bees as well!

The Eco-CORN Quicklock nesting trays produced by Beediverse Products provides housing not only for spring mason bees, but other insects as well.

We are not sure what the bee species is in this photograph, but  it shows the yellow pollen carried on the base of the bees' abdomen.  This makes it a solitary bee in the Megachilidae family - the same family as the mason bee Osmia lignaria and the alfalfa leaf cutter bee, Megachilidae rotundata.  Gary G. from Sechelt, British Columbia, sent these photos to me for publishing on this blog.  They were taken on 15th July 2010.

The rough mud plugs are typical of the early spring mason bee.

A summer solitary bee species using a nesting tunnel of a LODGE with Corn Quicklock nesting trays
 The big advantage in using Quicklock trays (as in this photo) is that they can be pulled apart and cleaned.  Cleaning nesting trays removes mites and other debris so that cleaned nests can be used each year. In these photos you can see that two pieces of nesting trays make up 6 nesting cavities/tunnels.  Each nesting tray neatly fits together to make 30 nesting holes.  The name of this house is the LODGE and is available from your garden store or on line at

Note that no paper liners are necessary with this system.  The internal walls of the tunnels have a mat finish to counter the usual slippery finish of plastic material and these nesting trays are made from 80% CORN material making them more attractive to bees than straight plastic.

Especially in the wet west coast climate, avoid mold on the surface of cocoons (although this can be washed off with bleach water) by opening up nest early in the fall.  Late September is a good time to harvest cocoons and clean out your mason bee nests.

Tuesday, January 18, 2011

Yurt made from re-bar

Tim and a re-bar yurt

You may wonder about my fascination with yurts.  This fascination with yurts has been with me since I saw the yurts in Saskatchewan and at the same time the realization that yurts of this type would be a good structure for mason bee housing.  A yurt might just be the answer for creating a warm environment at a time of year when temperatures are often cool.  I think cool spring weather is our biggest problem in being able to produce lots of mason bees.  Even under cloudy and windy conditions temperatures are quite a bit warmer inside the yurt then outside.

The re-bar yurt was constructed by J.Gaskin.  Re-bar makes it as strong as the yurts of Saskatchewan (these were  made from iron pipe) and because of this strength, nests could be hung from the yurt itself.  Also, it could hold a significant number of nests, like in the alfalfa fields for alfalfa leaf cutter bee pollination.  The re-bar at the base of the yurt could be pushed into the dirt for added stability.
Hole in roof. Re-bar is welded to metal
ring.  Note white tarp was used for the roof.
Skirt buried under soil to prevent air
 movement  into yurt from base of the
This yurt consisted of 3 rings of re-bar and 8 verticals.  When I draped the material around the framework, I found that another ring of re-bar would have been useful at the height where the re-bar was bent to form the roof. Also, when hanging up the Highrises inside the yurt, I found that the Highrises were not easy to attach to the re-bar.  A special hook of some sort would make it easier to hang Highrises on the wall and would make it easy for removing Highrises for harvesting and cleaning.

Cocoon Release houses.
Each holding about 200 cocoons.
Highrises filled with a variety of interlocking Quicklock
 nesting  trays.  Note painted letters on front of nests to
help bees orient to their nesting tunnel.


This yurt worked well for the bees. The size definitely makes it more suitable for commercial use rather than for use in the home garden. It was too big for a 4x4 and had to be hauled to the site by a farm vehicle.

Now all we have to do is design one that is suitable for the home gardens, one that can be used for small orchards and work for the larger commercial acreages. 

Sunday, January 16, 2011

Washing nests and houses, few versus many

Lots of nesting trays for cleaning!
For  gardeners, setting out nests, harvesting cocoons and cleaning cocoons and cleaning nests is manageable.  I always say- do it early in the fall and then it is DONE!   However, when Christmas comes around there are always nesting trays that have escaped the early fall cleaning session!

It is more difficult if the nest cleaning is done in the middle of winter because the drying process has to be done inside.  This is no problem with cocoons since these usually air dry in about an hour or so (dry cocoons is a cool room, otherwise bees will emerge).  But the housing or shelters plus the nesting trays need to dry too and you need space for that.  When you have as many nests as the upper picture, winter cleanup is near to impossible unless you have a barn or large space to do it in.
Using  water, under high pressure
for washing trays.

 When you have one or a dozen nests, cleaning them with a scrubbing brush is no problem.  But for larger quantities,  cleaning them becomes a big job.

One year we had an opportunity to wash nesting trays with a high pressure hose.  Even though it was labour intensive because each trays had to be handled, the cleaning job was superb.  The water removed all signs of mud mites and other debris.

Both trays and Highrise shelters were dried in the sun and readied for re-assembly.  This is easy because both the wooden nesting trays and the newer Quicklock Corn trays can be inserted into the Highrise shelter and hung up into our yurts or like in earlier years, can be set up in other types of structures.

The Highrise- is a boon to managing mason bees in large quantities.

Both Highrise and Quicklock nesting trays can be obtained from

Cleaned wooden nesting trays.
Cleaned Highrise shelters drying
in the sun.  (black containers in background
are pots for blueberry plants- nothing
to do with the washing process
or mason bees)                  

Friday, January 14, 2011

Searching on this blog and Seminars.

I have added a Search window on this blog.

 This will be handy if you are interested in any particular topic. For example, I searched for the word 'mite' and the search engine found 4 POSTS that used the word 'mites'.  You then click on any of the posts you   choose to read.

Similarly, you could search for the word 'seminar' to see if there are any events near your location.

Thursday, January 13, 2011

Introduction to mason bees- How to do a seminar

When I started my company, Beediverse Products, my evenings and weekends were quickly taken up with running fall workshops, spring seminars and going to quite a few conventions.   During a very busy time, I decided to 'clone' myself by producing a DVD "All about mason bees" !

Of course, my reason for producing the DVD was to make it easier for anyone to run an Introductory seminar on Mason Bees.   The DVD is a core piece of information for any seminar on mason bees.

This DVD is an integral part of learning and teaching about mason bees.  This DVD has sectors on the bees flying around and superb photography inside the nesting tunnel.  It also explains pollination and how to manage mason bees.  

Another great tool to have when you do seminar is the Lifecycle poster.  Wen Lin and I created the lifecycle/ management poster in color using Andi Lonon's beautiful sketches.  This poster is a powerful tool in helping people understand the idea of solitary bees and their lifecycle.

Here are three ideas I would present at a seminar on the "Introduction to Mason Bees"

1.  Show them a nest or two and tell them where to hang the nest.  The best location for any nest is on a East facing wall of a shed or house, under an overhang and in the sun.  Also show them where to place the cocoons- preferably under cover of the nest and close to the nesting tunnels.

2.  Go over the lifecycle using the lifecycle poster.

3.  Show them the sections on the DVD of mason bees flying in and out of the nest, mason bees inside the nesting tunnel and the section on pollination.

Both the DVD and the poster can be obtained on-line via the website

Bumble bee in flight-summer

With all this cold  snowy and icy weather around I thought a picture of a bumble bee flitting around should be the order for today.

Wednesday, January 12, 2011

2011 Northwest Flower and Garden Show in Seattle- Feb 23-27th

Dr. Margriet Dogterom
in the foreground

  Every year Beediverse Products are available at the Seattle Flower and Garden Show.  Jim Tunnel owner of Beez Neez (Snohomish)  has the booth at the show. 

Date: Feb 23-27th, 2011.  Come and meet us at the booth.

Beediverse Products at the Beez Neez booth.

Jim with a customer
These photos were taken in 2008.  We were kept  very busy with all the questions that gardeners have about mason bees.  It is a lot of fun. 

This year, I will be doing  a 10-15 min  mini seminar three times each day:  10am, Noon and 4pm. 

See you there!

Mason bee trial in a blueberry field

These photos are bringing back some great memories of my time on the 'farm' with mason bees. 

We tested various types of nests, and to duplicate these, I bought 50 small office garbage cans. 

A set up used in a mason bee trial
in blueberry field.

I set each one on  top of a fence posts. 

Unfortunately, bears could not resist going after the small amount of  pollen inside the nesting tunnels.  Several of the containers were smashed to pieces. 

Mason bee trial in a blueberry field.  Bears smashed quite a few of the containers with mason bee nests.  In the distance two other containers are visible sitting on top of a post.
  After this, I realized that bears were one of the challenges for keeping mason bees in these fields.  I knew that bears go after honey bee hives, and yes, beekeepers kept their hives surrounded by electric fences.  But I did not think that bears would go after mason bee nests.  I guess early spring bears are hungry and anything goes. 

In photos of previous posts, you can see the electric fence surrounding the nests.  It is easier to have many nests surrounded by one electric fence,  than having numerous locations each with an electric fence.   

Large mason bee nesting area surrounded by
an electric fence.

But concentrating mason bees in one area begs the question about the distance that mason bees fly.  This of course will determine the distance between mason bee houses/set-ups.  Another factor for consideration is flower density.  Distances flown will depend on flower density.  The question I find most intriguing is whether the female to male ratio changes depending on the number of cocoons set out at any one location.  If you set out say 1000 cocoons will these produce more females then when you set up 20,000 cocoons?  A good PhD project for someone.

Steve E and his mini-yurt for almond pollination

Steve E from California, contacted me about setting out mason bees in an almond orchard.  He asked me for feedback on his idea of constructing a housing unit for mason bees out of a plastic barrel.

" I brought the two plastic tubs into my garage and took this photo of the 2 containers side by side.  You can see that the all-blue barrel is uncut, while the white one has a cut-out door of about 12" x 16" bordered by black tape.  Within the barrel are stacked cinder blocks.  You can make out a roll of cardboard tubes within one cinder block.  On top of the cinder blocks is a wood bee block.

So, if these barrels are only 33 inches tall (a bit less than one meter), are they too short to be effective ?  The diameters are 23".  I could put a stack of cinder blocks out with a wood pallet on top, and elevate the barrel on the pallet to gain some height.  But that would make it more vulnerable to the wind, as well as more work and materials for multiple sites.
I can obtain these barrels quite easily, and they are simple to cut out.  The temperature within vs. without is at least 5 degrees warmer on a sunny day.  On an overcast day, at least the blocks are protected from the wind.
I can put vent holes in the top or upper edges.  But these are targeting February and March activity in an almond orchard and plum orchard, and it is generally lower to mid 50's F in those months.
Please comment on the potential efficacy of this simple housing unit."
COMMENTS:  The bees may behave/forage/fly differently in the blue and white unit.  Setting them side by side would make for an interesting test.  Cut a hole in the center of the top (4-6" diam) so excessive heat can escape.  Also disoriented bees can fly out through the top and re-orient to their nesting tunnel after flying through the door.  Set cinder block against the sides, so to avoid any rain coming through the skylight hole and falling onto the nesting tubes.  Secure  from wind.  Set out in an open and sunny location.   Set up 3 thermometers: 2 inside at different heights and one on the outside north wall for comparison.  I look forward to hearing more about this housing unit.

Tuesday, January 11, 2011

No buildings for setting out nests in blueberry fields

When I started  producing mason bees, I set the mason bee houses onto a barn and shed of a blueberry farm.  This was easy.  But the farmer also wanted mason bees in his blueberry field to make sure the mason bees were pollinating his blueberry flowers far from his home and barn.  But there are usually no buildings out in these commercial fields for setting out mason bee houses.

Mason bee cocoons and their nests require a few basic essentials.  They need to stay dry and during the day need to be warm- in other words, a dry spot, in the sun and preferably out of cooling winds.

I came up with using Garbage pails, set up on its side.  Theywere secured to a post and with a few other pieces of  lath, secured to the post because some of these places can be quite windy.  It worked rather well.  The set up time though was long because no field had the same type of post. 

Tim setting up a "Mason Bee house".

Cardboard tubes were used at the time and bundles of these were set in the back of the container.  To help the bees orient to their nesting tunnel, cotton batten and "1" foam was interspersed amongst the layers of nesting tubes.

The middle of the container was used the most by the bees.  On some days, under sunny conditions, it became very hot in the upper section of the container.  It looked like bees were avoiding the excessively hot area of tubes.  To "cool it down a little, I cut a small hole in the upper part of the "roof" of the container.

There usually is a lip to a garbage container so that the lid can be fastened to the garbage pail.  Unfortunately, when the container was on its side, rain pooled in the rim drowning many bees.  I cut a drainage hole so that water would not pool in the rim.

The container was set up about 4 feet above the ground to avoid the splash zone and also to avoid the cooler ground temperatures.

When we started using routered nesting trays, these stacks did not fit very easily into the round container.

We learned a lot from this trial. 

The yurt was still a few years away!

Sunday, January 9, 2011

Candling mason bee cocoons

I have had some questions about candling mason bee cocoons.  Joe Sadowski from Burnaby, BC thought of this idea- and it works.  Candling is just like candling eggs.  In a dark room you shine a bright light under the cocoon.  With some experience, you can see the adult mason bee in a fetal position inside the cocoon.  You can also see empty cocoons or non- viable cocoons, where the larva has died and not developed into a adult bee. 

Here is a batch of mason bee cocoons.  Mud has been washed off, and mites have been removed.  After washing them, cocoons take about an hour or so to dry and then candling can be done.

Place dry cocoons on a petri dish or similar container,over a 6 Volt flashlight.  It is easiest to do the candling in a room without windows.

Turn the lights off in the room and look at the cocoons.  You will be able to see right through empty cocoons.  In normal light, these cocoons look like normal viable cocoons.

You can also see the viable cocoons with the bee inside the cocoon.

Rock, move and rotate petri dish over the light.  The light scatters and allows you to see the non- viable cocoons.

All cocoons sold at Beediverse are candled and non-viable cocoons removed.

Saturday, January 8, 2011

Frank M. from Victoria, BC sends photos and writes about his mason bee "harvesting group"

I'm writing to tell you briefly about our 2010 harvest, and also am sending some images of weird and wonderful things that we encountered in the process.
As for the harvest itself, I'm not going to send you all the data but will simply summarize.
I had 13 people in the group this year.  Altogether we set out 3110 cocoons, and  we harvested 3124.  Not a banner year by any means, but at least sustainable.  
Here are some photos.  I'd be pleased to receive any comments or suggestions about these, Margriet.  It seems that every year we find something more weird and more wonderful than ever.  
I should also mention that I'm using the stainless-steel-screen technique to remove additional mites after washing.  I did it the first time an hour or so after washing and drying, with very good results, I'll do it again this month while they're in storage, and a final time when I take them out of storage to distribute to the members of our group..
This photo (below) is of a group of 15 strange rusty coloured cocoons that we found in just one tray from a nesting box on Galiano Island. They seem to be covered with sticky pollen or something that stains the fingers.  Image 009 shows how the cocoon material itself is sort of layered.  When I tried to open some of them I found that there was an outer layer that peeled away, with some sort of cocoon-like structure underneath.  Inside that I found only a thick creamy coloured fluid that oozed out.  Any ideas? 
COMMENTS:  This is a species of summer mason bees, that uses masticated leaf materials for its chamber construction.  I have never opened one, so it is interesting to note that the content is still in the pupal stage of development.  The final stage of development would occur when warmer weather begins in spring.
This photo (below) shows a gallery with eight compartments constructed from pine resin, for goodness sakes!!.  Four of them have tiny caterpillars in them.  They look superficially like the ones in Image 002 but they are much smaller.  There is no doubt about the pine resin (or some conifer), because it was sticky to remove and as I worked it I could smell the familiar fragrance.  Again, any ideas?
COMMENTS:  This looks likes some resin bees in the pupal stages of development.  They would develop into an adult resin bees and emerge in the summer when the resin is soft.
This photo (below) shows wiry brown frass completely filling a compartment.  There were two or three of these compartments. The entomologists at the Museum thought it might be fly frass.  Never seen it before.
COMMENTS:  Does anyone have any ideas on this one?
The photo below shows how easily the mites can travel from one gallery to another.  
COMMENTS: The brown-reddish granules are the pollen feeding mites.  One or two or more land in the chamber in spring and mites consume the pollen.  What you get is a million mites and no bee.
This photo (below) shows another type of caterpillar.
COMMENT:  It could be a beneficial wasp pupae. 
This shows (below) a cocoon completely covered with dark brown rods of frass.  The question is .. whose frass is it and how could it have been placed while the cocoon was completely enclosed by mud and the overlying tray??  I've cropped the image so you can see it better.
COMMENTS:  When a mason bee spins its cocoon, it leaves its frass on the outside of the cocoon.  The different colours of pollen indicates that multiple species of plants were visited when collecting the pollen.
This photo (below) shows large creamy coloured 'caterpillars'. 
COMMENTS:  This compartment contains no bee, although it is the compartment made by a mason bee.  These grubs were laid in the compartment while the female mason bee was completing the construction of the compartment.  The brown stringy frass may belong to this insect.

 NOTE:  Usually I would not disturb the cocoons and the pupae like the resin bees, but close up the nest and set the nest outside.  The reddish frass and the multiple pupae in one cell, looks like it came from a predator of some kind and I would remove it from the nesting tunnels.

Friday, January 7, 2011

? Fruit fly larvae in mason bee nesting tunnel

Photo #1.  Joe S. from Burnaby, BC showed me this interesting occupant of his Beediverse Quicklock nesting trays. The photo above shows 2 nesting tunnels.  The upper tunnel shows a common sight.  It looks like sawdust, but actually is a collection of pollen feeding mites amongst pollen. The lower tunnel contains a mason bee cocoon on the left hand side and a group of pupae on the right hand side.  The whole cell with the pupae was very sticky.  It looks like these insects have consumed a lot of the pollen/ nectar mixture that the female mason bee had collected for her offspring.
We have never seen this inside a mason bee nesting tunnel, and we are wondering what it is. 


Photo #2 is a collection of fruit flies.  Joe has never seen such persistant fruit fly activity as last year (2010).  The question is whether these fruit flies are the same as the pupae in photo number one.  If anyone knows if this is the new Cherry fruit fly, please let us know.

Thursday, January 6, 2011

Beneficial wasp pupae inside a mason bee nesting tunnel

Hartley R. from Vancouver BC, forwarded me a photo taken by Daryl A. from Vancouver, BC and asked for some feedback. 
This blue nesting tray (an Eco-Quicklock corn tray from Beediverse) contains a beneficial wasp pupae.  The adult collects either spiders, aphids or larvae as food for its offspring.  The adult beneficial wasp paralyses the food and then lays an egg on top.  By the end of the summer, the beneficial wasp larvae or grub has eaten its food supply and develops into a pupae.  The pupae overwinters and emerges during the late spring or summer months when temperatures are right.  A great beneficial insect!

It has a very fragile paper like covering so I usually leave it inside the nesting tunnel, reassemble the nesting tray and set it outside again  - ready for next season. 

Wednesday, January 5, 2011

Mason Bees,Resin bees and leafcutter bees

This is how some insects overwinter, protected from the winter elements and predators, until the following spring.  When you open  routered nesting tunnels or Beediverse Corn nesting trays, you may find all kinds of insects using the nesting tunnels.  

The top row consists of leaf cutter bee cocoons.  It is difficult to see the individual compartments each containing a cocoon.  Leaf pieces tend to overlap from one cell to another.  Different shades of green probably means that pieces were chewed off from different species of plants.  
The mid row contains  pupae of the resin bee.  Resin bees use tree resin as cell liners and dividers.  The bee larvae feeds during the summer months, until it grows into a pupae.  This little yellow 'grub' overwinters in this life stage form  until warm temperatures allow it to develop into an adult bees.

The 3rd and lowest nesting tunnel contains the mason bee or the spring mason bees Osmia lignaria.  It uses mud to make its compartments- save from predators and the weather.

All three insects are pollinators.  Leaf cutter bees and Resin bees generally pollinate during the summer months, whereas Mason bees pollinate in the early spring.

When opening nesting tunnels, I return the nesting trays to their housing with the resin bee pupae and leaf cutter bee cocoons intact.  I remove the mason bee cocoons, and process them.  Processing these cocoons means removing the mud and any mites that may be attached to them.
Photo by Mike N., North Vancouver, BC

Tuesday, January 4, 2011

Summer Solitary bees including Resin Bees

A great photo by Mike N. of Vancouver, BC.  It shows 3 out of 4 occupied nesting tunnels. The three occupied nesting tunnels are full of overwintering solitary summer bees. The upper nesting tunnel was not used by any insect.  The middle two nesting tunnels are filled with cocoons of a bee species that uses masticated leaf material for the chamber walls and partitions.  You can see the greenish material on the sides of the cells.  The pale yellow and orange pellets over the surface of the cocoons are fecal pellets produced by the developing and feeding larval stage.  The different colours show you that this bee foraged for pollen from two different plant species.

In the 3rd row from the top look at the contents.   The 5th and 7th compartment (counting from the left) do not contain a cocoon.  What it does contain is a load of pollen that the female bee has deposited in the cell.  The pollen is still present because the new bee in its larval or grub stage has died, leaving the pollen.  This can happen under cold weather conditions.  Bee larvae basically starve since it is too cold to eat.

The 4th and lowest nesting tunnel contains resin bees.  These are solitary bees that use resin or tree sap to make their nest partitions and nest walls.  The resin is rock hard and is great protection against any predators who might want to feed on them.  The life stage is actually the pupal stage.  This is the way it overwinters.  In the summer months each pupa grows into an adult bee, and when the resin softens, adults emerge and begin the cycle over again.

When you find these occupants in your nests, leave them the way they are in the nesting tunnel.  These occupants are beneficial to your garden.  They will pollinate your plants during the summer months. Close the nest and set it out where offspring will emerge when the temperature is right.

Monday, January 3, 2011

Summer mason bees that use masticated leaves for nest partitions

Happy new Year!

A great way of learning about bees and insects is to have a close look at what other critters are using the nesting tunnels besides solitary bees.

This is a photo of routered tray that has been used by insects.  You can see the green lining and the green cell divisions, made from chewed leaf materials.  Inside each compartment is a cocoon containing a hibernating bee.  The bee may be fully or partially developed.  Some species overwinter as a pupa and develop into the adult bee  the following spring/summer.  The yellow/orange pellets are fecal droppings, and the yellow wash is pollen not eaten by the developing bee larva.

These "summer mason bees" come out and pollinate any time between May and September.  Each species is around for about a month.  They usually use a smaller diameter nesting tunnel than the spring mason bee Osmia lignaria.  The nesting tunnel diameter used is anywhere between 3/16" to 1/4"or 4-7.5mm, depending on the size of the species.

The insect inside the lower tunnel, is a fly!  A bee has two antennae.  A fly does not.  Flies do have a hair like structure, but is not visible in this photo.
Photo by Mike N.Vancouver BC