News from the bee house

Fortunately the solitary bee season coincided with warm sunny weather in late spring and early summer.  Now it is wet and gloomy the season is almost over but it has been fascinating to watch and mostly very successful for the bees.  The most numerous residents of the bee houses are always red mason bees.  This is a female in the observation wing having a brief rest before setting off to forage again.

In most previous years I have had between half a dozen and a dozen completed red mason bee nests.  This year, with my new bee house, I have about 80!  Here are 34 of them.

In the next photo the rear cell is complete with a food store of pollen and nectar and an egg. Work has started on the front one contains a bit of pollen and a pool of regurgitated nectar.

A few days later it looks like this.

Here is another bee coming back with a load of pollen.

The bees always reverse in to unload pollen.

Here are a couple of bees plugging the entrances to their nests.

There was one blue mason bee nest from last year with nine cells.  The front six were males. This is one of them.

Once they had chewed their way out of their cocoons five of them sat in the nest for another 24 hours before deciding to brave the outside world.

The females emerged a few days later and one of them moved into my new bee house.

She uses chewed leaves rather than mud to the build the cells.

Here she is in the precess of laying an egg.

Another bee in the new house was a common yellow face bee (Hylaeus communis) but she completed only three cells.  She made several more cellophane walls along the hole before sealing it so three was all she planned.  The nectar pollen mix she brought in was almost black.

The observation part of my original bee house is still in use and this year, for the first time, it was host to a leafcutter bee.  I was very pleased until I realised that she was lining the cells first before working on them so I couldn't see what was going on!  The nest was in an old red mason nest, hence the mud lining.

The bee house has a wire mesh covering as protection against woodpeckers.  Rather than risk dropping the leaf if she flew through the mesh, this bee flew in the bottom each time and then flew vertically upwards to reach the nest.

I was struck by the precision in the final work to seal the nest.

Another resident of the "bee" house was a mason wasp, a solitary wasp that uses mud in the same way as the red mason bee does.  It used a smaller hole and filled the cells with caterpillars rather than pollen.  Here it is clearing out sawdust before starting to build cells, with a red mason bee in the background.

There were other solitary wasps which were tiny.  They made their own holes in the wood, about 1mm in diameter, and stocked them with aphids.  Louise Hislop, our local bee & wasp expert, says they are Passaloecus sp. females.

Perhaps the most exciting bees I saw in the bee house were fork-tailed flower bees.  They nest in rotten wood so I made one panel out of dried rotten wood, specifically in the hope that they would move in.  I made three small starter holes and was surprised and delighted to see that for several days two of them were excavated by female fork-tailed flower bees.  But although I often saw the bees pushing their way out through clouds of sawdust I never saw them going in with pollen.  I wonder if they didn't fancy the holes after all after all that digging.  With luck they did continue when I wasn't looking.  I'll be able to remove the panel later in the year to take a look.

I am already making plans for next year, to make sure there will be room for perhaps an even larger population of bees.

More news from the bee house

A third species of bee has moved into my new bee house this summer.  After the red mason bees and a blue mason bee, two female common yellow-face bees (Hylaeus communis) built their nests in 4mm holes.  These bees are tiny, around 6mm long, and are black and shiny rather than hairy because they carry pollen in a crop, not on their bodies like most bees.  The cell walls in the nest are made of a waterproof cellophane-like material, secreted from the bee's Dufour's gland (close to the sting) and applied with its tongue.

I first noticed them on 12th July but both were already hard at work so they must have begun a few days before.  Here is one of them with one cell complete and busy marking out the next one. (For an explanation of the mud wall at the back see below.)

Here is the other one, marking out cell walls with cellophane.

The next day I found another Hylaeus communis nest in the old bee house.  All the holes there are 8mm and must seem cavernous for this tiny bee.  She had also been hard at work for several days and was stacking her cells on top of and beside each other.

Each cell contains a porridge of pollen and nectar to sustain the growing larva.  Here you can see an egg in the front cell.  The egg is quite big compared with the size of the bee.

Here the eggs have hatched and the larvae are already well grown.

Here is the bee in the old bee house, hard at work on another cell wall.

  

She eventually ran out of steam (or eggs) after building about a dozen cells but sat around for a long time afterwards, tinkering with the last cell wall.  I last saw her on 10th August, over a month after she arrived.

A few days before the Hylaeus bees arrived something else (presumably a couple of solitary wasps) had built a few nest cells in the 4mm holes and then disappeared before the nests were complete.  The cells were separated by mud walls and provisioned with tiny paralysed grubs but I never saw what had put them there.  This is on the west side, with red mason nests above and below.

And this is on the east with what I presume is a tiny egg on the window in each cell.

A third wasp nest has only three completed cells but was sealed with mud at the entrance so that wasp thought its work was complete.  Only a couple of the wasp cells look viable but it will be interesting to see what emerges next summer.  Whatever it is may have to wait until the Hylaeus bees emerge as they are blocking the exit.

Solitary bees and wasps are targets for all sorts of parasitoids.  I noticed this female parasitoid wasp, Gasteruption jaculator, sniffing around but didn't see it enter any of the nests.

And this is a kleptoparasitic ruby-tailed wasp, Chrysis spp.

I already have plans for another bee house for next year, offering even more luxurious accommodation for all sorts of solitary bees and wasps. 

Bee of the week - Yellow-face bee

This tiny bee is not quite 5mm long and is easily overlooked.  It is the common yellow-face bee (Hylaeus communis). These photos are all of females on Phacelia in the garden.

Hylaeus bees are solitary and share the most unusual characteristic of carrying pollen back to their nest holes in their crop rather than on a pollen brush (scopa) on the legs or abdomen.  These bees can be seen "eating" blue pollen from the anthers of Phacelia.  While I was watching they were landing on the flowers and then climbing up the filaments to reach the pollen.

Hylaeus bees nest in small holes in wood, woody stems, etc and I have seen them in my bee house, although I didn't manage a photo. There are 12 Hylaeus species listed Steven Falk's Field Guide to the Bees of Great Britain and Ireland but most are localised or rare.

The bee that swallows pollen

I have been on the look out for this bee since being alerted by Louise a couple of weeks ago.  It is a Yellow-face Bee (Hylaeus bee) and is tiny, being little bigger than an ant.  I managed to take a few photos of females on Astrantia in the garden.

I could see these are female as they have 12 segments in their antennae (rather than the 13 in males) but I was puzzled not to see any sign of a scopa.  (That is the pollen-carrying brush in solitary bees, usually either on the hind legs or under the abdomen.)  Then I read that the female Hylaeus bee swallows pollen and carries it to the nest in her crop, rather like other bees do with nectar.  Here is the bee "eating" pollen from Sweet William (Dianthus barbatus).

I found the males very difficult to photograph because they fly so fast and very rarely land on the flowers.  I suppose they must drink nectar at some time but I didn't see it.  They are mostly interested in finding a mate.  Here two males are attracted to a female on a flower.

The unlucky one, behind, shows his face clearly enough to confirm he is Hylaeus communis,  the Common Yellow-face Bee.

Mating is a very brief affair, watched here by an even smaller something, possibly a wasp.

I am amazed at the variety of bees that have been living in my garden without me knowing and by the many ways in which they live.  I'm still looking out for more.