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.
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.
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.
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
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.