A good spring for Osmia cornuta

My bee houses have been rewarding me with lots of activity from the Osmia cornuta in the past weeks.  I’m sure they don’t need any help to find hollow nesting places but when they choose my hollow bamboo canes or drilled-out wood I have the pleasure of watching their antics.

The first I know that some bees have hatched is the frantic activity of the males.  This 17 second video gives you an idea of what it looks like.

I admire the tenacity of the males who guard the holes against all comers.  You can get the idea in this 16 second video.

The male can be easily recognised by the little tuft of white hair on his head.  They are around several weeks before the females eventually hatch and then the excitement really mounts.

The mating is not an elegant affair and this pair managed to get stuck in the tube in a sort of impasse where neither was prepared to cede defeat.

I noticed this mating pair under the box and I was surprised by the females stoic non-resistance.  That was until I saw the photograph on the computer and noticed that the male had a firm grip on her wings and back legs.

The male eventually decided to dismount and release her.

The female is a very attractive bee and is larger than the male, which is not uncommon in bees.  She lays her eggs in hollow stems or crevices and supplies the future larvae with pollen for nourishment.  She pushes the pollen firmly in place with the help of two little horns on her head.

The horns are under the antennae and as the horns are black they are difficult to see amongst the black hairs of her head.  They are best seen in a photograph.

Once the females have emerged they begin their frantic search for the perfect hole.  Despite the abundance of choice from our point of view the females have a need to explore.

Eventually one will meet her high requirements and the egg laying and pollen collection will begin.

Pollen collecting is a serious business even if putting it in place can get a bit messy.


21 thoughts on “A good spring for Osmia cornuta

    • I have placed a lot of different bee houses around the garden and selected different orientations to test which direction is most popular. They have all been used but it is the ones with the longest hours of full sunlight that are the most popular. Also the bees do not really need our help but it is for us to have the pleasure of watching them. So it is very convenient that they like the sunny sites as it is more pleasant to watch them in the sunshine and easier to get good photographs for a record. Amelia


  1. Our granddaughters built a bug hotel for the garden last year. I haven’t yet seen bees using the bamboo canes, a bumble bee used one of the bird nest boxes. Do you know if we have that spieces of bee in the U.K.. I have seen masonry and leaf cutter bees.


    • You don’t get Osmia cornuta in the U.K. but soon, we will both be seeing a very similar one – Osmia bicornis. You may well have/get that one in the bug hotel and also the leaf cutters later. It is nice to have the bumble bees in a nest box. Mine have been in the soil (B. terrestris) and in our stone walls (B. lapidarius). Amelia


  2. Very interesting and lovely pictures, the Osmia bicornis here are still some weeks away from emerging. I have been experiencing some problems with bee hotels, they get serious attacks of mites and I am beginning to think that new tubes are needed quite often. Have you experienced any problems?


    • I have not changed my tubes and I have left the same holes in the wood. I have not seen mites on the Osmia. I have seen very suspicious flies around the boxes this year but then I saw two lizards on a box with flies. That made me think the lizards could be keeping them clean and not just be pests that knock out the tubes. There are mites in bumble bee nests that only feed on the nest debris. It is very difficult to tell what damage the mites are doing. Amelia


  3. Your bee hotel is so attractive. you’ve inspired me Amelia; I know there are lots of bees who find nesting places in the garden but you’re right it would be lovely to be able to watch their antics.


  4. That looks a very promising start to the spring, Amelia. We’ve returned from a trip to find one housefly poking around the tubes, sneering (as far as I can make out). Any bee of any kind would be welcome right now… RH


  5. Pingback: March in the garden | a french garden

  6. Pingback: First female of the season – Bees in a French Garden

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