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.
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
Charley, an old friend of mine started with mason bees a few years back. He loves the challenge of wood and design. We often talked about the yurt. At one point he asked me “What do you need, how long and high must this be..?”. He said “Ï’ll have a go”. Some time later he came back with his yurt in the back of his red pickup truck. He said, “I do wood work, but I don’t know anything about sewing”.The structure was complete, but it needed a tarp. So, I bought some tarp material and set to work. Draping the tarp around the uprights was easy. A few staples held it in place. It took me a bit more work to do the roof.design. The tricky part with the roof is that you cannot have any folds, because the bees might get caught in amongst the material. I ended up stapling the material to the roof after sewing the pieces together.Charley’s yurt design. We painted a black bee design on it – just for the fun of it.Inside of Charley’s designed yurt. A piece of plywood over the uprights held the base of the roof pieces. The upper parts of the roof pieces were attached to the roof hexagon.
The corner uprights were made from 1.5 x 1.5 inches. Two pieces of thin lath was used to hold one Highrise with nesting trays. Each Highrise was hung onto the lath with two hooks.
Tim standing next to Charley’s finished yurt.
Three rows of Highrises fit into this size yurt. Each Highrise is filled with our Quicklock Eco-Corn trays
Soil is added to the extra length of tarp to prevent wind from going underneath the tarp.
This yurt worked great: Mason bees did not get caught in any part of the structure, during the day the temperature was always warmer inside ( but never over 30 Celsius). It is definitely sturdy. I did try it out in Cawston BC, and I was told that it may get very windy on some days. To make sure the yurt did not topple , I tied 3 guy ropes to eye hooks and to a fence. More recently I have simplified this by setting the yurt adjacent to a sturdy post and tying a rope around the yurt and fastening the rope to the post. This works well.However, this design is a little complex- we are mainly speaking about the complexity of the roof design. Also, not everyone has a welder so that pieces of re bar can be fastened to each of the six ‘feet’ of the yurt.We need a design that is simple to assemble and set out in a garden.Over the next week or I want to tell you about our other yurts, their advantages and disadvantages. I want to show you our yurts made of re-bar and made of irrigation pipe.I also have a collection of photos of what people have found in their mason bee nests. Fascinating!…More next time.
Every year more cocoons were produced and so we build more nests.In this particular year stacked boxes are sitting on top of large fruit totes. I did this so bees could freely fly in and out of their nest. The problem was that the wind also caught the nests. It was not surprising to see that the lower nests shielded from the wind by the blueberry bushes were filled first.
Here are another couple of stacked large box-like structures to protect mason bee houses during the pollination season,
Stacked box Sysem for pollinating field crops
The small boxes with holes at the front are ’emergence boxes” for releasing bees (contain 100-200 mason bee cocoons). In this setup, there are 8 on the left hand side of the upper shelf and 3 on the upper shelf on the right hand side. I ran out of emergence boxes, and had to use an old bird nest (upper LHS).
One problem with this structure is that it catches the wind and it makes it more difficult for bees to fly in and out of the nest. The wind also makes it colder around the nests.Note the electric fence used to prevent bear damage. For increased stability, 3 posts were hammered into the ground and nailed to the boxes.Looking back to these structures, the yurt is a dream to use. In the next few blogs, I will be writing about our yurt designed by Charley Ford. The uprights are no problem , but the roof design is a bit tricky.
Before we used corn nesting trays inside yurts, we used wooden nesting trays in wooden structures (picture below). Here, we are dealing with thousands of cocoons. How to release them is a good question.
With alfalfa leaf cutter bees, cocoons are set out in open trays (see previous blog), bees emerge and then fly to nearby nests. I have tried this method, but gusts of winds or something upsets the trays and all cocoons end up on the ground.
The system I normally use for setting out cocoons is to place them into small wooden shelters as seen in this photograph. On the upper shelf in this picture there are 3 shelters on the left hand side and 3 shelters on the right hand side. Each shelter contains between 100- 250 cocoons. The little door on the front of each shelter has a hole from which mason bees emerge. I find this shelter system the most secure way of releasing cocoons, no matter how many cocoons I have.
This old cedar shake cottage, which was probably a livable house at one time, is the perfect place to hang a few nests for mason bees. There are lots of reasons why this might be a great place to produce mason bees. The house itself, provides a place out of the rain with its overhanging roof, the cedar shakes on the sides of the building probably have mason bees amongst the shakes already, it is a warm location, protected from winds by some huge trees, and it is in the sun.
Cedar shake cottage – and ideal location for mason beesNot only is it a warm location in direct sunlight, but the warmth of the shed wall would stay warm long after the sun had gone down. This is important in keeping bee larvae active and feeding.In addition,the owner, has lots of fruit trees and blueberry bushes adjacent to the house providing abundant food sources for the bees. And, most importantly, no pesticides are used on the property.You can imagine my surprise when I produced fewer cocoons in the first season than the number of cocoons I set out. The 3rd and 4th years were no different. The fifth year the bee population exploded. A collection of mason bee nests on the east facing side of
a cedar shake cottage. Odd shapes, colours and layout of nests
helps the bee in finding its own nesting tunnel.
I initially thought some freaky weather pattern made the area cooler and not very attractive to bees. But the 5th year’s explosive growth countered that argument. If production continues to be good, than food and other weather related conditions must be ok for mason bees.
My theory now is that during the first few years, there were so many available nesting holes in amongst the cedar shakes and the density of bees so low, only a few nested in the mason bee houses that I had set out. As the years passed, the cedar shake nesting holes filled up and mason bees began to use the mason bee houses in earnest.
If this is true, then natural nesting holes will be used first since these are more attractive then most man-made nests. After a few years mason bees will start using mason bee houses.
Note: All man-made nests and cocoons were cleaned every fall. Wooden structures were cleaned and scrubbed. Cocoons were washed free of mites, and later candled to identify and destroy any parasitized cocoons.
After a dinner at a community hall one year, I wandered through the surrounding garden and I was delighted to see this crab apple tree with all its fruit. Since it was fall and all the leaves had fallen, these pink crab apples, small and large, made a showy and colourful picture. Because I studied pollination and pollen loading of blueberries, I was off course interested to having a second look at the pollination of this tree. I wanted to see if there were any patterns of where the large and small apples were located on the tree. One pattern was very clear and can be seen in this photo. The more accessible flowers on the outside of the canopy produced larger fruit. This means that flowers on the outer canopy received more bee visits because more pollen was deposited on these flowers. The lesser accessible flowers on the inside of the canopy are small and received fewer bee visits. Flowers close to the ground also produced small fruit.
This tree did not receive optimal pollination. If the plant is healthy, the two major reasons why poor pollination occurs is insufficient bees or poor weather or a combination of these two factors. If poor pollination occurs in good weather, then insufficient bees is the more likely reason for poor pollination.
People often ask me how many mason bees must a garden have for good pollination. Fruit production is a great way to tell if good pollination occurred during the previous spring. If pollination is good for a series of 3-4 years, which includes a poor weather year, then sufficient bees are in the orchard.
Lack of good pollination produced both large and small crab apples.
After our trip through Saskatchewan, the idea of a workable yurt for mason bees began. I was fascinated by the roof opening and how it apeared to work nicely with alfalfa leaf cutter bees. Since leafcutter bees and mason bees are in the same family a yurt like structure might just work for mason bees.
I had one experience with leafcutter bees that did not work very well at all. But I did learn from the experience.
I built a U-shaped structure using regular poly on the surrounds. The roof was made of solid wood. The open part of the ”Ú’ acted as an open door. Bees emerged and started nesting. After a couple of days, I was back and to my dismay, the leaf cutter bees were getting caught between two layers of plastic stapled to the wooden uprights. The stapling kept the plastic on the structure, but if a bee became disoriented, she would fly agains the poly and then over time end up between the overlaid plastic walls. Many were caught. I removed a lot of them by cutting the plastic, but this let the wind in and ….basically this structure did not work at all.
The yurt cover is made from one piece sewn together to form a snug fit. If a bee does get disoriented in a yurt, she ends up flying out through the roof, and back into the yurt via the door. A great solution for disoriented bees.