In respect of the purchased plastic-based habitats, there was a strong smell of plastic the ‘off-gassing’ from the materials used. This unnatural aroma led me to think that it might put off the bees who normally seek holes in wall or tress, so yes having left the untouched habitats outside over winter (2009/10) has meant that the gases are less strong.

One mason bee did take up the opportunity last year but it’s progeny didn’t return to nest in the habitat. However this is probably due to the fact that (despite it being exposed to the afternoon sun) it was North facing and the bee prefer morning sun. I left it there, because I have begun to realise that to expand my bee population I must be able to to clean out the parasites in the tunnels. If not, the young bees can get blocked by failed cells, get pollen mite infestations, or the Cacoxenus indagator (bee flies – see my post) would start to really infest the habitats (as they did in 2008) and thus put a brake on the bee population expansion. So you do need to be able to disinfect the tunnels without harming the bee cocoons inside (hence my choice of habitats since).

For your other questions: The white plastic insert habitats were designed to be flush with the wood, so they are essentially ‘sealed’. Other habitats were much more successful however, but I put this down to the choice of habitats that they have – wood drill blocks, brown paper tubes and reed/hollow-stem plants (pond reeds, dried hogweed and Japanese Knotweed +). It means that mean the bees (and different species that arrive at different times) can choose to nest and remain where they are most comfortable. My own bee observation boxes (using 10cm cut of narrow plastic hose) have no off-gas problems and are sealed at the back by the wooden dowelling that hold them in place in the hinged roof box.

Thanks for commenting.

“I placed one [masonbeehome habitat] next to my main block when the bees were active, but none were occupied. So they will be left to winter outside – hopefully to be ready for next season.”

Do the white plastic habitats have closed off ends? Were other habitats more successful? If so, which habitats were preferred, and why do you suppose they were better?

Happy to share my sources – I found these @ http://www.masonbeehomes.com. (tell them who recommended them, thanks)

…and they are not bad, but there’s quite a bit of off-gassing (a strong smell of plastic) from the two-block one house set I bought in 2008, and I don’t know whether this is off-putting for the bees. It was only this year that I had one bee creating three cocoons, and this was after I left the honeycombs exposed to to the wind all the winter. To be fair the block wasn’t in the brick wall area where most of my bees are active.

If you buy two, you can rotate the blocks, but you won’t be able to retrieve or disinfect the cocoons if mites or other fly parasites such as Cacoxenus indagator move in, but I guess you can clean out the honeycombs.

It really depends if you are wanting to harvest the cocoons, or just leave them alone. If you fancy harvesting cocoons and/or keeping the parasite population down, I would also recommend AndrewsReclaimed at Etsy, and this particular nest block with trays which you can take apart and disinfect: http://www.etsy.com/view_listing.php?listing_id=28132782

Let me know which way you go, and above all I would love to hear about your success/history with solitary bees. Email me – Paul@ this domain. Cheers.