Whether you are on a budget, or wish to recycle paper to test for mason bees, here's a how-to photo-montage:
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:
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 :
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:
So time to help the bees, but thoughtfully. Go find some parcel paper or recycle those old office envelopes !