Small, red and black

Tuesday 15 May 2018

I visited a large, SW-facing organic pasture near Hendre, NW Monmouthshire, ungrazed since the previous year. The recent sunny weather on this day produced a really interesting list of bees. This includes sixguttulata ed. different nomad bees, one of which is described in Falk and Lewington’s Field Guide as ‘a very scarce species’: Short-spined Nomad Bee (Nomada guttulata). Nomads are cuckoo-bees, or klepto-parasites, which lay their eggs in the nests of others, usually mining bees.

The small, red and black cuckoo-bee was flying with its host, Red-girdled Mining Bee (Andrena labiata, also small, red and black) in a labiata ed.corner of the meadow, over a patch of Germander Speedwell, the mining bee’s favoured flower. Only when I got the cuckoo bee home under the microscope and followed it through the Field Guide key did I realize what I had found. My identification was confirmed when I sent it to a BWARS expert.

While the mining bee is ‘rare and mostly coastal’ in Wales (though it is present in Drybridge Park, Monmouth), the cuckoo bee is much rarer than its host.

The other nomad bees were (using Steven Falk’s English names): Marsham’s, Fork-jawed, Gooden’s, Painted and Flavous. Three other cuckoo-bees (small, red and black again) were Blood-bees (Sphecodes): Box-headed, Geoffroy’s and Red-tailed.

labialis ed.Besides these I found nine other non-parasitic bees, including several males of Large Meadow Mining Bee (Andrena labialis), which I first found at this site. It is the only bee in this story not small, red and black.

Its cuckoo is the Red-tailed Blood Bee (Sphecodes rubicundus) below.rubicundus ed.

The number and variety of cuckoo-bees flying about in the Spring makes one wonder how their hosts manage to replace themselves at all.

 

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Red Dead-nettle & early bees

Saturday 14 April.

The first warm(ish) spring day of a slow, dull year. An old pasture on the margins of Monmouth is carpeted with Red Dead-nettles beneath its ancient oaks.

P1130766

 

RDN is a fragile annual usually seen on roadside verges or in neglected corners of gardens. It grows easily on thin bare soil, and it is a favourite with the Hairy-footed Flower Bee.

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There were several of these, both the brown males and black females, easily detected by their loud hum, their dashing flight and unusual bee-practice of hovering. Below is a female recovering from a brief sleep in the fridge.

 

P1060098Crawling about on the flowers in more lumbering style were bumblebees in small numbers, mostly big queens including Buff-tailed, White-tailed, Red-tailed both Large and Small. My guess is that under the thick, tall hedge bordering the field are some good nesting places.

 

P1100387A number of much smaller bees turned out to be Short-fringed Mining Bees (Andrena dorsata), a neat little insect with red furry thorax and black shiny abdomen with thin, buff-white bands, broken in the middle. This is a common bee in Monmouth, and it comes in two generations, spring and summer. Later in the season it is regularly found on bramble flowers. This one has found a globe-thistle in the allotments.

 

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The Bilberry Mining Bee

Bilberry Mining Bee, Andrena lapponica

Another Bilberry specialist, this time nearer to home.

Walking in Trellech Common woods, above the Lower Wye Valley,  in the first week of May, I noticed some large Bilberry patches under the trees. Trellech Common bilberry patchForaging on the small pink flowers half-hidden by the leaves there was a good selection of bumblebees, mostly Common Carder, and Early Bumblebees, a few large White-tailed queens, and one or two Tawny Mining Bees – it was almost as bee-friendly as a well-stocked garden.  I took home an odd-looking white-tailed bumblebee that turned out to be a female of the cuckoo-bee Bombus barbutellus – a new one for me.

Trellech Common bilberry under treesI knew there was such a thing as Bilberry Mining Bee, which from its name – Andrena lapponica – sounds as if belongs to the far north, but saw nothing unfamiliar. I remained ignorant but hopeful, and came back twice more to loiter among the trees with my bee net.

Trellech Common bilberry

On the third occasion, I saw a furry red and black bee clambering around in the Bilberry canopy.

 

 

A. lapponica f.

 

This turned out to be the sought-after Bilberry Mining Bee. It is a handsome, medium-sized bee, with a black head, abdomen and legs, a red pile on the thorax surrounded by a golden fringe with long golden hairs on the front of the abdomen.

Silent Valley spoil heap

 

A few days later, in Silent Valley nature reserve near Ebbw Vale, I found several more of these bees at a nesting site on an old iron-ore spoil heap, now overgrown by heather. I did not see any Bilberry nearby, but the bees were laden with its white pollen, so probably found it higher up the mountain.

However, on the day I found the first bee I did not find any of this species – or any other bees for that matter – in a place where they might be expected: the open, sunny heathland of Beacon Hill NR,  where there is much Bilberry in flower, and which is less than half a mile from Trellech woods.

The opinion that it’s no use looking for bees in woodland (which I must have picked up from some authority), is proven to be false. At least, flowering Bilberry – and some sunlight at ground level – will bring in generalists like the common bumblebees as well as the specialist mining bee Andrena lapponica.

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The mountain bumblebee

Bilberry Bumblebee, Bombus monticola

I have found this scarce upland bumblebee at three locations in Monmouthshire: the high moorland between Blaenavon and Blorenge; Coity Tip reserve on the other side of Blaenavon; and the extensive heather-covered hillside a few miles north of Abergavenny.Heather moor

It is probably best to look for it in August when the heather is in full bloom. In spring and early summer it needs Bilberry, which grows among the heather but which flowers much earlier. It benefits also from Gorse, clovers, Bird’s-foot Trefoil and other upland flowers.

This is a colourful bee with yellow, black, faint grey bands and a striking red abdomen.

There is a slight resemblance to the male B. monticola 3Red-tailed Bumblebee B. lapidarius but  monticola is smaller, broader in the body and has four red abdominal segments (right) unlike lapidarius with only three (below). They can easily be told apart in the field.

It is said to be declining everywhere. I suspect that the overgrazing of upland moors by sheep, the reduction of heathers and subsequent spread of bracken is not helping.

b. lapidarius 1On my short visit to the Abergavenny site a few days ago I found between 30 and 40 bumblebees of which about a quarter were monticola, alongside various white-tailed species, Common Carder and Red-tailed. Without knowing the results of recent surveys, this seems to me to be still a healthy population.

 

B. monticola 1Like all bumblebees, they will not pose for the perfect shot but are always on the move to the next flower while you are pressing the button

The  continued existence of this beautiful bee in Monmouthshire is probably dependent on the deliberate preservation of moorland with its characteristic mix of plants – and fewer sheep, if any.

 

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A rare cuckoo-bee and its host

Stelis phaeoptera and Osmia leaiana

In July 2014 I found two small black bees on Yarrow in my garden that I did not recognize. Searching my keys I identified them as Stelis phaeoptera, a cuckoo-bee species. It does the kind of thing cuckoos do, i.e. lays its eggs in the nest of another species, killing the young and taking its food. Its own egg then hatches and feeds on the pollen store.  It’s a well developed way of life among bees, practised by about a quarter of all species I have found in the Monmouth area.  Many more cuckoo bees, often beautiful insects, will appear in this blog, I hope.

This is now the third year I have found Stelis phaeoptera. In 2015 I found a second species, which I will describe in another post.phaeoptera 1

This bee not outstandingly beautiful. Falk’s name for it – Plain Dark Bee – just about sums it up. But it’s a neat insect in its own way: short-limbed, compact, heavily armoured and, of course, without any pollen brush. The integument is covered all over in what look like tiny pin-pricks.

The host in this case is most probably a bee which is common in my garden and for which I provide nest tubes: Osmia leaiana, the Orange-vented Mason Bee. It is about the same size and cylindrical shape – adapted to crawling into tubes – and a busy pollen gatherer. They are both fond of knapweed and scabious. Side by side the similarities are apparent:

     O. Laieanaphaeoptera 1

All four British species of Stelis are said to be rare bees, and phaeoptera particularly so: ‘a much declined species’ according to Falk, with very few recent records. I am lucky to have it, even if its host isn’t.

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Smallest bee?

Lasioglossum minutissimum

I have now found two other insects sharing the big nest aggregation I wrote about in my earlier post. One is a very small, mostly black, hunting wasp, Lindenius albilabris, which stocks its nest with even smaller flies and plant-bugs.Lindenius hole I have previously found this in the Forest of Dean, nesting in the hard surface of a pathway at Crabtree Hill, constantly in use by walkers.

The other is the smallest bee I have yet found, Lasioglossum minutissimum, a member of the same group as the malachurum bees I previously wrote about. It was in the bottom of my net after a sweep in the low vegetation of the nesting area – a tiny black insect just 3.5 millimetres long which I otherwise would not have noticed.

minutissimumBack home and under the microscope it showed by its branched hairs that it was a bee, by its 13 antennal segments that it was a male, and by its wing venation that it was a Lasioglossum. Apart from its very small size, its distinguishing feature is a shallow groove across the abdomen between the first and second segments.

Once I have found a bee for the first time, it often begins to appear in other places where it was unnoticed – in this case on the banks of the Monnow opposite the castle and at another site along the Wye at Dixton. Now I have learned to sweep the low vegetation and not to rely on spotting the bee first, this tiny insect appears to be fairly common around Monmouth. It is said to forage on a wide variety of flowers.

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Gregarious and social

Lasioglossum malachurum

On the West side of Monmouth, along the edge of Sergeant’s Wood and Sergeant’s Grove Seargant's Grove 2there are some large nesting aggregations of a small mining bee Lasioglossum malachurum, sometimes called the Sharp-collared Furrow Bee on account of its square ‘shoulders’ which can just be seen with a hand-lens. (‘Furrow’ refers to a groove in the last abdominal segment of the female, characteristic of all Lasioglossum and Halictus bees.) It is a common bee in the Monmouth area, though at only 7 millimetres long it doesn’t fit everone’s idea malachurum 3of ‘bee’ and is easily missed.

Besides being gregarious – having many nests in one place – this bee is truly social though not on the scale of honeybees and bumblebees. In each nest, the founding queen and her daughters co-operate to forage and raise the next generation. It has been much studied by evolutionary biogists because of what it can tell us about behavioural origins of social living. There is a good article on it in Wikipedia.Field 12 (2)

 

The largest aggregation contains about 1500 nest holes, which I counted using a metre square, though there may be up to twice this number, since many are hidden by vegetation or beyond the margins of the measured area.

Field 12 (4)The nest entrance holes are close together – up to 60 per square metre – and made in hard clay with thin vegetation, often on the pathway.

An uncomfortable half-hour squatting in the malachurum 4hot sun produced nothing better than this photo of a worker (probably) about to go back into its hole at the sight of a digital camera.

 

 

 

The Field Guide to the Bees of Britain and Ireland, says that Lasioglossum malachurum ‘is not recorded from . . . Wales’.

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Making homes for leafcutter bees

A simple construction built with metal cans and bamboo tubes has attracted several species of tube-nesting bees to my garden since I first tried it in 2011. They include leafcutter species which line their nest-cells and seal the ends with discs cut from leaves, laying an egg on the food store in each cell. The most frequent in my garden is also the M. ligniseca 01biggest: The Wood-carving Leafcutter Bee, Megachile ligniseca, larger than a honeybee, though quite different in appearence.

Here is how I make them:

1. From a supermarket get fruit or soup cans of two widths, one of which will fit inside the other with a narrow space between their walls. The small one should be the same length, or a bit longer than the large one. Remove the tops and use the contents. Wash and dry the cans. After a season in the garden they will rust, but that doesn’t matter.

2. From a garden centre get several bamboo canes, not too narrow and not too wide. Choose sections with apertures from 9mm to 12mm. Using a saw, cut them into equal lengths, the length of the small can or slightly longer. Avoid the nodes – they should be open at both ends. Remove the pith with anything you can conveniently shove through, like shirt-hanger wire.

3. Pack enough tubes into the smaller can to fill it and wedge them in tight.hotel 02

4. Find a fence post or wall in a sunny place facing SE to S. Drill a hole through the end of the larger can and fix it up with a screw, from 3 to 5 feet above the ground.

5. Fit the small can into the large one and wedge it in with pieces of split bamboo.

You are ready for the bees, though it may take a while – up to a year, even – for them to discover it. Once used successfully the tubes will be inhabited year after year. I have seen them do their own spring-cleaning in June.

In September or October when nest-building is finished, remove the inner can and store it in an unheated shed away from the rain. This will avoid damage to the bee cells from severe weather and small birds during the winter months. Remember to bring it out again in April the following year and put it back in place. The bees will emerge in early Juneleafcutter 02

Some of the tubes may be used by mason bees – of which more in a future post – and they will be sealed with mud rather than leaves. And some of the tubes will attract ‘cuckoos’ of various kinds, notably Sharp-tailed Bees which lay their eggs in leafcutter cells (again, a future post). In my opinion these are as much worth having as the leafcutters themselves.

Leafcutter bees love dry, rotting wood and I have found that a woodpile nearby greatly woodpileimproves their habitat and increases their numbers. They will sun themselves on it and even find holes in which to nest. It’s best to stack the logs on end so that rain drains off quickly.

In my garden the large leafcutter finds pollen and nectar from Spear Thistle (the favourite), Knapweed, Scabious, Meadow Cranesbill and Borage at different stages in the season. Unlike honeybee workers the females collect pollen not on their hind-legs but with a brush on the underside of their abdomen, which is unusually mobile.

Nest-building activity seems to reach a maximum in the first two weeks of July. You will hotel 03see the female flying in every few minutes with her leaf discs, fitting them in the tube and dashing off for more until she fits the final disc on the end.

So far, I have no idea whether, having finished stocking a tube with nest cells, a female leafcutter will then go on to stock others, or whether, job done, she retires or dies of exhaustion. I would welcome observations on this.

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Longhorn Bee

The Longhorn Bee, Eucera longicornis

Longhorn Bee male My bee of the year 2016! This large solitary bee has disappeared from many British counties in recent years. This may be due to the loss of its main foraging plants – especially Bird’s-foot Trefoil – from farmland. Luckily we still have enough left in the Monnow Valley to sustain the bee at several sites. These include the banks of the Monnow at two locations, an organically managed farm near Hendre and the flower meadows at Kingcoed, owned and managed by Monmouthshire Meadows Group. I think the Monmouth area could be one of its last strongholds in Britain.

The male is umistakable, though it dashes about in the grass at speed in May and early June and its amazing antennae are not obvious until it’s in your net.

Long-horned BeeThe female, as it forages on legumes in July, can be mistaken for one of the faded Common Carder Bees doing the same thing, until you get a close look at its hairy buff hind legs and black abdomen with  white bands at the rear.

Here is a female on a large patch of Bird’s-Foot Trefoil that has escaped the mower near the river bank at Perthir

 

 

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