Leaf-Cutter Bees and Bumblebee Nests

Posted on Jun 22, 2012 in Blog, Other | 3 comments

I just went outside to check if my spare nucs had frames in them and when I took the top off one, found what I think was a Bumblebees nest inside.  That go me thinking about some pictures I took last year, of what I think is a Leaf Cutter Bees nest, so have found them to add here too.

Inside a Bumblebee Nest

This first picture is what I’m pretty sure is a bumblebees nest, I have watched to see who is coming and going, but I’ve never spotted her, so if anyone knows otherwise please let eggs in a bumblebee nestme know. The great thing about this nest is that she decided to move into one of my polystyrene nucleus boxes which have a transparent cover board under the roof. She has laid her eggs right up in the corner where it’s probably nice and warm, but used the cover board as part of the egg cells, this means I can lift the roof and see straight inside without disturbing them.

It looks like the Bumblebee queen starts the nest off by building the cells, filling them with pollen and laying an egg in each one.

The two in the upper right corner must have been the first to be laid, as they have already hatched out and you can see they are larvae now as opposed to eggs, like the cells on the left. I am guessing that the one at the bottom is the new one which she is working on and will be filled with pollen, have an egg laid in there and then be sealed up. Although, I’m not quite sure how the ones in the corner are going to get out when they emerge as adult bees, without disturbing the ones which were laid later! Perhaps she didn’t think that one through properly.

Leaf-Cutter Bee Pupae

leaf cutter bee larvaeLast spring I was tidying up the greenhouse and found an old pot of dried out soil tucked away in a corner, I took a hand-full out and crumbled it onto one of the beds, then as I went to take another, I noticed some weird cigar looking things buried in it. As you can see from the photograph, there were about 10 or so all buried in the same pot. They looked like a tiny cigar, rounded off nicely at one end and with a perfectly cut circle of leaf blocking the other, then some soil pushed in the recess which was left. Not knowing what they were at the time, I picked one up and peeled it open, there were several layers of dried leaves all perfectly formed with a small grub inside. At this point I took a couple of pictures, put them back in the pot, covered them back over with some dry soil and put the whole thing back where I’d found it.

Once I went back inside I decided to do some investigation into what they are, but found very little cigar shaped cell from leaf cutter beeson the internet, a few questions in gardening foums etc, then I found a site which had some hand drawn pictures of the pupae stage of the leaf cutter bee and a realised that’s what they must be (no pun intended). Unfortunately I can’t find that site again, but I have seen bees very similar to the picture of a leaf cutter bee on the wildlife trusts website, so am pretty confident. The only thing which still confuses me is that they say that they nest in dead wood, cliffs and inside the stems of plants, there’s no mention of them burrowing in the ground to raise their young. Again, if anyone knows anything about them please leave a comment and let me know. Thanks.

 

Oh Go'waan, Click One...

3 Comments

  1. The top picture could be some kinda solitary bee nest

  2. I’m also intrigued as to where these bees usually make their nests as a few days ago, we noticed a bee regularly flying into our (closed-up) garden parasol. Due to the awful weather this year, we’ve hardly used it, but opened it this evening to discover a green cigar shaped nest fixed to the underside, which we managed to remove, unfortunately disturbing one bee at the same time. It’s a real shame we’ve had to do that, but it couldn’t stay where it was.
    Do you know if it’s unusual to have these kind of bees in the UK?

    • Hi Alison,

      I only know about honey bees, but there are loads of solitary bees in the UK (over 250) so I expect the nest you found is the type of thing they usually build in a tree, wall or underground. Perhaps with all the rain this year the soil was waterlogged so this one looked for somewhere up off the ground, but that’s just a guess.

      Thanks,
      Steve