Back to the wall of bees

I first wrote about the bees in this wall seven years ago.  It is an old cob wall near the church in Nether Heyford, Northamptonshire, one of several similar walls in the village.  The wall is hundreds of years old and is home to hundreds or even thousands of bees.  They are all solitary bees and most are either hairy-footed flower bees (Anthophora plumipes), common mourning cuckoo bees (Melecta albifrons), or red mason bees (Osmia bicornis). When I visited a month ago most of the bees I saw were male hairy-footed flower bees, hanging about in the hope of finding a freshly emerged female.  When I returned last weekend all the males had gone (having mated and died) and the females were busy provisioning their nests in the holes in the wall.

This one is just leaving for a foraging trip.

Here is a female returning with pollen and nectar.

The bees remember roughly where their nests are but sometimes take a few moments to locate the right hole.  Their navigation might be put off by me standing in the way.

Each nest has several cells, each containing an egg and enough pollen and nectar to sustain the growing larva.  These two bees were shovelling loose material back into their nests, presumably to seal in a cell they had provisioned and completed.

Aggregations of hairy-footed flower bees attract a kleptoparasitic cuckoo bee, Melecta albifrons.  The females of this bee loiter near the nest entrances, hoping to sneak in and lay their own eggs while the owners are away.

The male bees hanging around the wall this time were red mason bees (Osmia bicornis).  Their flight season is slightly later so most of the females were yet to emerge.

Here is a short video to give a flavour of what was going on.  Three species are visible, female hairy-footed flower bees (round and black), common mourning cuckoo bees (thinner and dark), and male red mason bees (small and red).

A few yards away in the churchyard I saw Melecta albifrons,

ashy mining bees (Andrena cineraria),

and tawny mining bees (Andrena fulva).

Mining bees have a similar lifestyle to flower bees and mason bees but they dig their nests in the ground.  They also attract their own specific cuckoo bees.

Back at the wall I found a spider that had just captured a cuckoo bee.  The spider was also hiding in one of the holes and had built webs across several of the others.  It was in the process of wrapping the bee, which was still alive, and then appeared to bite it, presumably with a venomous or paralysing bite.

I think this is probably a female noble false widow (Steatoba nobilis).  This spider first appeared in Devon 150 years ago, having been imported from the Canary Islands in a consignment of bananas, and is now widespread across the southern half of the UK.  For a description of the false widow spider and some amazing photos see Jason Steel's website.

Spring is later up here in the north so I hoped some of the local male A. plumipes would still be around.  Yesterday I was in Morpeth, 10 miles north of here and 230 miles north of my mother's village, and there they were.  I don't know where the nest site is in Morpeth but I saw several male bees sipping nectar in the town centre.

There were more females on the wing, this one showing how her proboscis splits to show the tongue and folds away underneath her "chin" when not needed.

The Morpeth hairy-footed flower bees were first recorded last year and are spreading south through Northumberland, presumably from the original outlier population in the Alnwick Garden.  I hope it won't be long before they reach Newcastle.

Andrena scotica

Here is another bee that lives in a wall.  This is Andrena scotica, also known as the chocolate mining bee, presumably because of its colour.  Although it is a solitary bee, the females nest close together in an aggregation and several in a group share a common entrance to their nests through a gap between the stones.  The first bees I saw on cool morning were males, just hanging around outside.

A few females were popping in and out, ignoring the males and looking as though they were already busy nest building, although none was carrying pollen.  The females have a characteristic black and white scopa (pollen brush) on their back legs.

Like most solitary bees, Andrena scotica is parasitised by cuckoo bees, in its case mostly Nomada marshamella.  This is a female.  I have yet to see a male.

Bee of the week - Nomada goodeniana

This week's bee is Nomada goodeniana, Gooden's nomad bee.  It is a cuckoo bee, laying its eggs in other solitary bees' nests, just as a cuckoo takes advantage of meadow pipits etc.  Below is a female.  She has no pollen brush (scopa) as she doesn't need to collect pollen.  Unlike cuckoo bumblebees, which often resemble their hosts, nomad bees look radically different.  This bee is a cleptoparasite of Andrena nigroaenea, which was bee of the week last week, and of A. nitida and A. thoracica.

This female Nomada goodeniana is investigating an Andrena nigroaenea nest hole, trying to decide if it is safe to enter.

Here are a couple exiting, having just laid an egg in the host's nests.  When the egg hatches the larva will eat the host egg or larva and then eat the pollen which the host female has provided.  It will develop alongside the host bees and emerge with them next spring to repeat the cycle.

Nomad bees do forage for nectar but are probably less efficient pollinators as they don't have hairy bodies.  You can see how the antennae fold back out of the way as she goes deep into the flower.

The male Nomada goodeniana has black on his antennae and 13 segments in the antennae (compared with 12 in the female) but otherwise does look similar to the female and has the same green eyes.

This one looks pretty relaxed as he warms up in the sun.

Nomada goodeniana bees spend time foraging or prowling around their hosts' nest holes.

Nomada goodeniana is one of 34 British Isles species of nomad listed in Steven Falk's Field Guide to the Bees of Great Britain and Ireland.  The nomad bees are all cletoparasites, as are around 30% of all bee species.  Most solitary bees and bumblebees have one or more cuckoos that take advantage of them.

Bee of the week - Melecta albifrons

Melecta albifrons is a cuckoo bee, a cleptoparasite of last week's Bee of the Week, Anthophora plumipes.  It is found in and around aggregations of nests of its host.  The female flies or walks around the nest holes, looking for an unprotected nest in which to lay her eggs.

The male and female Melecta albifrons are almost indistinguishable in the field.  This one is a male as it has 13 segments in its antennae (as opposed to 12 in a female).  I think it was also newly emerged as its wings weren't quite fully expanded.

Being a cuckoo, the female doesn't collect pollen and therefore has no scopa (pollen brush) on her hind legs.  All she does is drink nectar and lay eggs.

Most Melecta albifrons are black and white, as in the photos above, but a few are almost entirely black, as this one below.  Melecta albifrons is also known as the common mourning bee.

Melecta albifrons is found in the southern half of the UK.  These photos were all taken in Northamptonshire.