Making tunnels for mason bees

Whether you are on a budget, or wish to recycle paper to test for mason bees, here’s a how-to photo-montage:

Mason bee parcel-paper nesting straws

Mason bee nesting straws made from parcel paper.

It takes less than a couple of minutes to make one tube + then you block one end with moist mud from the garden.  It’s a great evening activity in winter months and an opportunity to educate young people about nature and the marvellous events that occur in spring.

…and here’s proof that it works:

Osmia rufa (mason bee) nesting in paper straws

A mason bee – Osmia rufa – nesting in home-made parcel paper straws.

When you unroll the tubes to access the cocoons in the autumn to clean out anything that will prevent their emergence (like dead cells, mites or parasites) a perfect tube will look something like this :

Mason bee cocoons in paper-nesting straws

Mason bee cocoons in home-made paper-nesting straws – before and after unrolling the paper.

In the image (above) you see that nectar does seep/wick into the paper, however the lower part of the image shows that the cocoons will successfully develop without any problem.

Just one note of caution - as in natural tunnels, any mason bee cells located paper-straws, cardboard tunnels or reed tunnels will be subject to the attack of Chalcid wasps after the spring. 

This then means at the end of May or beginning of June when the female bees have finished nesting, you should gently move the completed blocked tunnels out of reach of these solitary wasps. You can put them anywhere warm even in the house so that the developing larvae eating the pollen inside their cells are protected (for example, I put them inside my bedroom on a high shelf, out of the way). 

They develop perfectly in the summer warmth of the house and the bonus is that mason bee pollen mites (not the same as bed or honey bee mites) won’t multiply in constant dry warmth, so you’ll have less of them when you check the tunnels in the autumn.

However, if you leave the nested tunnels out in June you may find this:

Chalcid wasp kill young mason bees

Chalcid wasps kill young mason bees – note white holes in paper a sign that wasps have eaten larvae and emerged.

So time to help the bees, but thoughtfully.  Go find some parcel paper or recycle those old office envelopes !

Posted in nesting habitats, paper straws, Questions & Answers, solitary bees | 26 Comments

Want to raise mason bees?

Here’s a visual report card so far on 5 projects of local people who’ve wanted to raise mason bees that I posted up a couple of months ago on the Facebook page:
Mason bee starter project report cards

Just over 40 people liked it and it was shared 16 times, so I was pleased the information was useful. The point of putting the photo together was to demonstrate:

  1. The value of putting out a block to test – none of these people started with any bee cocoons
  2. The value of having accessible tunnels (and the proof as why you have them – project#1)
  3. The interesting finding that for the orchard sited within the industrial zone (#3), absence of nesting suggested that industrial zone was a totally sterile area, probably where pesticides were used to keep things no greener than just grass.

At a later date, I’ll share further on my current attitude on cocoon sales and that I prefer to test for and work with the biodiversity of bees present in the local environment.

Posted in bee emergence, Cocoon harvest, learning curve | 5 Comments

Drilling holes in logs for Mason Bees

I put up a poster on the  page today to show solitary bee fans five starter projects that I have monitored over the last few years.  I entitled it a ‘Report card’ on the different successes or otherwise. What was great was that I also got three people suggesting they were seriously interested in taking up the hobby for next spring. You can see the report card picture on people who want to raise mason bees.

A fourth person messaged me through the CFSB admin. As I often can more rapidly and easily answer questions by email or PM or in comments sections of my video channel – as opposed to here where I get blogged down in excessive analysis and detail – I thought that it would it would make sense for me to share my response here under a Q&A tag so there could be a searchable record of them. So here goes.

A gent called Trevor asked me the following question:

I was looking to know what size of a hole do the bees need?? I was going to use a few logs and drill the holes into them??

My answer was:

You are in the British Isles, so it will probably be for species such as Osmia rufa (the Red Orchard Mason Bee) which prefer 6 to 8mm diameter holes. Get a very long drill bit so that the holes are at least a minimum of 10cm in depth and make sure the bores are clean and as smooth as possible, equally no burrs or splinters at the entrance to obstruct the entry of the nesting bee. The logs should be east facing and if possible protected as much as possible from rain and excessive wind.

These bees [specifically Osmia rufa] are relatively shy so best not to place the logs where there’s a lot of people walking past. Make sure the people that use the area know that he logs are not for the fire! Stick a little sign up – it’s a good talking point.

I would normally say put mason bee nesting tunnel habitats at least a metre off the ground also as to avoid humidity and an excessive curiosity from ants – mind you, if they are determined the best you can do is displace the logs a couple of metres to one side at night to break the ants path.

I would expect bees nesting mid to late April …and you may not see them initially as they are fast. The first sign is often a blocked hole. You may be lucky enough to also get leaf-cutters you garden area is just right.

Now the last question is when you get them, do you think you would want to have lots more? For example if you want them to pollinate fruit trees such as apple you’ll probably want to say ‘yes’. If that’s the case you’ll have to think about lining the log holes you drill with paper, or even putting out reed tunnels.

The deal is that any population of cavity-nester is often shortly followed or discovered by parasites (flies, mites and beetles). It’s a natural part of the ecology around bees. As you’ll see in the first drill-block in the report card (above), leaving the bees with tunnels that are not disinfected will mean that they’ll become clogged after two seasons and all your efforts will be lost as the bees move on. Or you can – as one person I know does – spend more and more time drilling holes to compensate for those that become unusable. Your decision.

As you can see I prefer that people decide and know how to correctly repopulate their local bees species rather than just abandon a project to getting clogged up.  Disinfecting can be left alone, but you need more holes than you believe and can end up constantly drilling holes in preparations for the next spring.

Unless you have the freedom to spend every spring sunny day on a chair right in front of the blocks (and someone waiting on you), you equally are never really sure whether the nest plug holes you see blocked up are this year’s new nest holes or last years blocked ones – with little bees struggling to get out behind unsuccessful nest chambers; an unsuccessful one in my book, may be a chamber full of mites, pollen loaves with a dead larva or chambers infested with multiple Cacoxenus indagator flies about to emerge and reek havoc with the efforts of the busy nesting female bees.

Posted in learning curve, nesting habitats, Questions & Answers | 8 Comments