Solitary Bees

I empathise with solitary bees. When we think bee I guess we tend to think of honey bees – the one species of truly social bee we have. They chat to each other and work in groups. They work to the greater good and share their tasks. It’s difficult not to think they derive some form of pleasure or satisfaction from their relationships with each other.
Bumblebees – technically “eusocial” – also belong to their own family in a nest. The queens are obvious and attractive and her sisters are “the sound of summer”. Everyone loves bumblebees.
Solitary bee emergingBut at this time of year, while honey bees and bumblebees are beginning to buzz around the garden in larger numbers, their overlooked cousins are starting to appear. The solitary bees are emerging.
Which type of bee is most “important” to us in its role as a pollinator is a moot point, but it seems sensible to think it’s these guys. For a start, there are well over 200 species in the UK – that’s a lot of different bees adapted to pollinate a lot of different plants.
They live everywhere; in holes in the ground, in walls, roofs, cliffs, and plant stems – I even have them in my bee hives, rather weirdly. It’s easy to persuade some of them to nest in an artificial bee box, unlike bumblebees. These are one piece of paraphenalia produced by the wildlife industry which work pretty well. You can even buy them with viewing windows in the side. If you wanted to make sure you had the optimum design you could even solitary bee houses.
There’s something rather plaintive about solitary bees. Their lives are brief and single minded and they go about them quietly, unnoticed and unheralded. Like so much of what’s living in our back gardens, unless we looked for them we wouldn’t know they were there.
Solitary bee boxLike other bees, all the males do is mate and generally lead a sybaritic existence. They are the first to emerge from the row of eggs carefully laid and provisioned the previous year, and hang around waiting for the females to appear.
The eggs inside the nest hatch and the larvae eat their food before making a cocoon and entering their pupal stage, which is how they overwinter – on their own, imprisoned in the dark for a year. The moment when they emerge is really magical. I saw one break the protective seal at the end of its tube in one of my bee boxes this morning. After a poo and a brief stretch in the sun he spent the next half hour loitering around the box waiting for a female to follow.
Solitary beeThe more common species are mason bees (like this one) and leaf cutter bees, Osmia and Megachile. The female bee finds a good spot to lay their eggs, and provision the end or bottom of the crevice/tube/hole/stem/etc. with a food bed made from pollen. She then lays an egg, and protects it by immuring it with a stopper of mud or leaves, making a cell. This is not a guarantee of safety; solitary bees have their own parasites and predators. She then repeats the operation. When she gets to the top of the nest she might leave at least one cell empty, to persuade woodpeckers et al there’s no-one at home. This often fails.
Her work rate is phenomenal. She is constantly to and fro, looking for nest sites or gathering pollen, mud or leaves, which she works assiduously to protect her offspring. And then, after around a month, she dies.

Solitary Bees and Wasps

I had an engaging day over the weekend at the Kingcombe Centre in Dorset learning about solitary bees and wasps. I knew a bit about them – particularly solitary bees – but now I know a whole lot more, particularly about some of the weird wasps out there.
Your back garden is home to all sorts of completely unexpected solitary wasps. Spider and bee killing wasps. Wasps that dig and wasps that build nests. Tiny wasps and wasps with enormous needle like ovipositors. I think I can tell all the Apoidea (bees) from the solitary and social wasps (Scoliodea and Vespoidea) now, and the terrifying Pompiloidea (spider-hunting wasps) from beautiful metallic cuckoo wasps (Chrysidoidea) and digger wasps (Sphecoidea).

Solitary wasps
Spider-hunting wasp (photo: BWARS)
Our instructor Bryan was entertainingly rude about honeybees and Spheksophobics (another cool Latin word). Why all the fuss about a single bees species – honeybees – he asked, when there were hundreds of other completely ignored solitary bee species out there? Of all shapes and sizes, they pollinate all manner of plants the honeybee couldn’t*. And why did people not realize the good wasps do – even those pesky social wasps, whose colonies do for an average 150,000 garden pests in a season?
Apart from improving my uncertain Hymenoptera identification skills and understanding what a fabulous solitary bee and wasp habitat our new green roof will be, some more general truths struck me. Three, specifically, and none of them new:
1. People’s perceptions of what is going on outside their back doors can be easily and dramatically changed.
2. We know the square root of nothing about what is happening out there, and display an amazing lack of curiosity about it.
3. We can create micro habitats for an incredible and beguiling variety of invertebrates more easily than spelling “Hymenoptera”. Doing it is an enjoyable business.
So I’m drilling more bits of wood for solitary bee houses to plonk on our green roof and trying to overcome my own pet phobia, born of years of incomprehensible science lessons – long classical names.

*No letters please!

Neonicotinoids again

I’m sure the various campaigns to ban neonicotinoids waged by people like Buglife, the Friends of the Earth and the BBCT are going to carry the day in the UK. I’m confident not least because they are backed by inceasingly persuasive science and, recently, Brussels. A number of retailers have started taking neonicotinoid based products like Bayer’s Provado off the shelves. Parliament’s Environmental Audit Committee is hearing evidence about them too.
Just as I thought neonicotinoids were about to get booted into touch in the UK, the agrichemical business is fighting a spirited rearguard action to save them. I wanted to pick up one point in particular from that, which I heard repeated again on the radio this morning by a man from Syngenta.

Foraging bumblebee
Stop!
Varroa has been a significant problem for honeybees. These are imported mites which attach themselves between the thoracic plates of honeybees and weaken the bees by sucking hemolymph. They also act as vectors for viral diseases. The European honeybee, Apis mellifera, has been defenceless against them. There are now treatments and ways of managing honeybee colonies which help the bees, and a lot of research is going on in this area.

The man from Syngenta said that bee losses were largely a consequence of varroa, not neonicotinoids. This is disingenuous. Recent research suggests the effects of neonicotinoids on honeybees are most marked when in combination with other problems, like the kind of viral diseases spread by Varroa destructor. The key point I wanted to make, though, is this. VARROA ONLY AFFECTS HONEYBEES. There is one honey bee in the UK. As I have blogged before, There are 26 Bumblebees and something over 240 species of solitary bees. Why are they declining? If it’s not varroa what is it? Some of the most persuasive recent research has looked at the impact of neonicotinoids on bumblebees. As for neonicotinoids’ effect on solitary bees (and butterflies, hoverflies, etc.), well… er… we don’t really know.

I did agree with the man from Syngenta when he said that banning neonicotinoids might not halt bee declines, and if it happens there’s a danger bees will disappear off the map of public awareness. There’s climate change, habitat loss, disease, new predators – all sorts of threats which still have to be dealt with.

Three Bees

There’s often general confusion between different types of bees, and I thought it might be helpful to clarify who’s who in a brief introduction. In the U.K. we have honeybees, bumblebees and solitary bees, and each are quite distinct. They all collect pollen (for protein) and nectar (carbohydrates) from flowers, but live in different ways and have different problems.

Honeybees
Bee_plants_crocusThere’s one species of honeybee in the UK – the European or western honeybee Apis Mellifera (Apis = bee, mellifera = honey producing).They can look darker or yellower, though, as there are different strains around. They are social bees, living in highly organized colonies of up to 60,000 bees, where they store large amounts of honey to eat throughout the winter. They travel up to 12km to find the nectar and pollen they need, and they forage in groups. Each colony usually has a single queen, who typically survives for several years. These are the bees we keep, and are most commonly mistaken for wasps.

Bumblebees
White-tailed_bumbles_sedumThere are currently 25 different species of bumblebee in the UK, although only 7 are common (including a recent import from France). Different species have different length tongues, adapted to collect nectar from different sorts of flowers; longer tongued bumblebees can access flowers honeybees and solitary bees can’t. People notice the queen bumblebees in particular, as they look for nest sites in the spring after hibernating or when the new queens fatten themselves up in the autumn (as in the photo). They’re big bees! Most bumblebees nest underground, often in deserted mouseholes or in places like compost heaps, and colonies are very small – only a few hundred. They’re not as well organized as honeybees and produce no food stores to over-winter on; the queens only last a season and the colonies break up in the autumn. They’re not as mobile either, and forage on their own over much shorter distances. They’re visually easy to distinguish from honeybees; they’re much furrier.

Solitary Bees
solitary-bee-3Astonishingly there are over 240 species in the UK. Hardly noticed, they go busily about the garden, typically nesting in the ground (mining bees), in wall crevices (cavity nesters) or in decaying wood (carpenter bees), according to the species. They can do well in the solitary bee boxes you can buy or make. They have relatively simple and short lives, which are concentrated on producing and safeguarding their eggs. These are sometimes protected with physical barriers constructed by the bees, typically made of mud or leaves – cut in neat half circles from plants like roses. We know remarkably little about solitary bees, which are thought to be the major pollinators of flowers in the UK. Oh, and they’re stingless.

Mimics
Hoverfly_Helophilus_trivittatus_asterThere are lots of flies which mimic all three types of bees for their own sometimes nefarious purposes. Hoverflies are often mistaken for them, but once you’ve got your eye in you’ll be able to see they fly very differently; hoverflies…er… hover.

Bee Problems
Honeybees, bumblebees and solitary bees have their own diseases and parasites, which are much more problemmatic when in combination with the issues below. The best known is probably the varroa mite, which has done terrible damage to European honeybee populations – to the extent that there are pretty much no wild colonies left in Britain. It is now treatable in the apiary, but colonies need careful monitoring.
There are a cocktail of other nasties which effect all bees more or less, depending on your point of view:
1. Habitat loss: there are fewer flowers around and fewer of the right sorts of flowers, particularly wildflowers. Bees also need a variety of pollen and nectar sources pretty much throughout the year, from early bulbs to winter flowering shrubs and trees. You can do your bit to help by planting some bee friendly plants, particularly those flowering outside the summer months. Different flowers are good for different bees; I’d recommend Plants for Bees as an invaluable guide.
2. Climate change: warmer winters mean bumblebee queens break hibernation and honey bees become active before spring – i.e. before there are flowers out. The queens use up their fat reserves too quickly and the honeybees their honey, so they starve to death. This can be the single biggest cause of honeybee deaths in a bad year.
3. Pesticides: This is the debate which currently causes the most heat and noise. We’re now using systemic pesticides, neonicotinoids, whose introduction in different countries seems to have coincided suspiciously with dramatic declines in bee numbers. As they’re systemic they effect any insect that feeds off treated plants, which unfortunately includes the insects feeding off the pollen and nectar these plants produce. There’s mounting evidence suggesting the damage to bees from them is significant.

Which Fruit Trees Should I Grow?

I want to grow some fruit trees, but where do I start? I don’t understand pollination groups or rootstocks, or the difference between a stepover and a cordon and a maiden and a bush. Help!

It’s a familiar cry. Folk quickly get bogged down when they’re shopping for fruit trees, as there are so many varieties and options open to them if they want to do things properly, rather than nip down to the nearest B&Q and end up with the wrong type of fruit tree. I’m faced with the same problem at the moment as we consider the possibilities for our new garden, so I went back to basics…

I like these...
1. Which fruit do I/we like? Grow the fruit you want to eat! Delicious they may be to some, but I’m not very keen on Medlars – so there’s absolutely no point planting them. Although it’s easier said than done these days, try to find different varieties to taste. Although they’er not West country varieties, I’m a big fan of the apples Ashmead’s Kernel and St. Edmund’s Pippin, which we’ll be planting; I originally tried them at a local farmer’s market – no way would you find them in a supermarket.

2. What am I going to use the fruit for? Is there a keen cook in the house? If there’s someone who wants to make jams and flans it will not only influence the varieties you buy, but also the volume of fruit you can deal with. You’ll also need appreciative consumers. You might not like cider, but everyone loves home made apple juice – which you can freeze as well as drink fresh. An orchard sized apple tree can produce something like 1000lbs of fruit – that’s a lot of apple juice! If you have several of one type of fruit, make sure they ripen at different times and/or that you’re buying a variety that stores well.

3. Do I want anything else from my fruit trees? You may have secondary considerations to think about, maybe aesthetic. You might want particularly attractive blossom, of a certain colour and/or timing, or you might like nice looking fruit. In the Mann household there are other considerations too – I like early flowering varieties for my bees, which leads me to looking at more exotic options like Almonds.

Big trees for a good workout
4. How much space do I have? By grafting onto rootstocks of different vigour you can have a tree of the same variety but very different size. Obviously, you’ll get less fruit from the smaller trees, but they can be a lot more convenient. We only sell varieties grafted on larger rootstocks – see here for details of sizes and planting spaces – but you can find really dwarfing rootstocks or, alternatively, “cordons”, which can be planted under a metre apart. You can buy trained forms as well, to grow up walls and along paths.

5. What are the local conditions like? It’s no coincidence that we are surrounded by apples as we have heavy soil and wet weather, which puts paid to Quinces, for example. Perry Pears do well hereabouts too, which explains why Babycham was made down the road. Plums, on the other hand, prefer lighter soils. They will stand the wind though and, consequently, work well in exposed sites or around the edge of a mixed orchard, where they will protect other trees. By way of contrast pears need sun and shelter. If you’re not sure what will do well in your own garden, do some research. Have a look around to see what’s growing close to you, and find out if there are any trees which have either orginated from the area or were widely grown.

6. Do I need to think about pollination? Mostly not. Apples are easy; there’ll generally be another apple or crab apple within a quater of a mile to act as a pollinator. Most plums and gages are self fertile. The only tricky customer is the pear, most of which are self sterile, so will need at least another tree in the vicinity. If you’re worried consult a pollination list, but I suspect the most important thing you can do to encourage pollination is to encourage the pollinators. Build your own solitary bee box or buy a posh one from us; they really work, and more bees means more fruit.

7. How big a tree should I buy? This is a different question to any consideration about rootstocks. You can buy a one year old “maiden” tree, which is little more than a stick, and if it has been grafted onto a vigorous rootstock it will grow into a tree over 4m tall in no time. It’s tempting to buy as big as tree as you can find; you’ll get fruit quicker and it will look more impressive where you need it to. On balance, though, try to avoid it. It’s not so much the obvious cost differential as how well the tree will develop – you’ve got a much better chance of successfully growing a long lived and healthy tree from a small sapling as from a larger tree (say 6 foot and over) that’s been wrenched out of the ground to get to you. You won’t have to stake it or dig a whopping big hole to plant it in, and it has a much higher % of its root system intact. Simples. Within a few years the sapling will overtake the bigger tree anyway. Don’t – whatever you do – buy some fancy semi-mature or even mature fruit tree. It will cost you a fortune and it will fall over.

I’ve put a tentative fruit tree order in for this autumn’s bare root planting season; you can see it on the plant list on the Hookgate Cottage site. I’ll be getting the trees from me, if you see what I mean, but if you don’t buy your trees from Habitat Aid please use a specialist British nursery.

Ecosystem-in-a-box

A report in Which? Gardening magazine, covered by the Daily Telegraph, tells us what we already secretly knew; that many “wildlife shelters” bought in shops don’t really work. An honourable exception in the report is the solitary bee box which, like ours on the left, is often better home-made anyway (many commercial boxes have only one or two sizes of hole and typically aren’t deep enough).

The report talks about bumblebee nesters as a typical example. We’ve always said to people that we’d prefer them not to buy them, and that they should rather concentrate on recreating bumblebees’ natural habitats. I could understand their apparent reluctance to do this if bumblebees, like other pollinators, needed unattractive plants. I could understand it if it were difficult or expensive to establish and manage these flowers. They are in fact lovely, they’re relatively cheap to buy and they’re easy to manage. Perhaps folk buy the nesters as part of an accessorization of their garden. Perhaps they buy them as a gift, or as a nod to “wildlife gardening”. From the retailer’s point of view it’s excellent news if they do, as they are easy to ship and carry a much better margin than plants. Good luck to them, but as a symptom of a broader problem it’s depressing. People are going to help and attract bumblebees if they plant the right flowers for them, regardless of how many nesters they have or don’t have. And it’s important they understand this; the Bumblebee Conservation Trust describes gardens as “a stronghold for some bumblebee species”.

How can we persuade folk that they can’t buy a brand new ecosystem-in-a-box at B&Q, take it home and unroll it in the back garden? The key to helping their favourite animals is to mend the broken one they have out there already.

Our Meadow in July

Greater Knapweed clumpMeadow BrownOur meadow is lovely at the moment; although the most obvious flowers are Greater Knapweed, Yarrow and Meadow Vetchling, the Self-heal and Lady’s Bedstraw are also out. The meadow is alive with insects; it is buzzing and clicking, chirping and rustling. Fantastic. I thought I’d stand in a clump of flowering Knapweed (Centaurea scabiosa) for ten minutes in the morning and in the afternoon and see what came along. I’m no entomologist, so please excuse the identification, but how gratifying to see so many friendly pollinators. Nothing out of the ordinary, but a good crowd.There were, of course, many more, either too small or too fast for this useless photographer, Six Spot Burnetbut at least this gives an idea of what you might help with a small meadow area…
Greater Knapweed is one of the best nectar plants, and it seems to attract all sorts of pollinators. Most obvious were the butterflies (and day flying moths). We’ve once again been swamped with Meadow Browns this year, but in my half an hour I also saw a Six Spot Burnet moth and a Small Tortoisehell. I’m sure we’ll have Gatekeepers later on too. Although Greater Knapweed seems to be just the ticket for butterflies, it is more of a struggle for our honey bees with their much shorter tongues. Perhaps surprisingly they’re not dissuaded, Small TortoisehellHoney beeand in the afternoon sun were the most numerous insect about, with two or three simultaneously working the same patch. They were very specific in their taste, as were the Hoverflies; not for them Meadow Vetchling or Lady’s Bedstraw. The solitary bees I saw were the same. Much quicker and more agile than bumblebees, there must have been at least 6 different species at work, although I only managed to photograph three. I’m still hopeless with my identification;Large Solitary Bee and KnapweedSolitary Bee and Knapweed I think there were Mason Bees of various types and Leaf-cutter bees too. Since we made our solitary bee box I have become more aware of these chaps and, consequently, see many more of them about, but still struggle to work out who is who. There are, after all, over 250 species to get to grips with and they all move fast. More work required. I am marginally more at home with bumblebees. Solitary Bee and KnapweedOur garden and meadow areas have become Bumblebee Central, thanks to judicious planting and management. Although we have plenty of Common Carder Bees (below top left), I’m still disappointed not to have seen the Shrill Carder Bee, but I live in hope! I think I have also seen Brown-banded carder bees (Bombus humilis) about, but I couldn’t be certain. The other unmistakable bumblebee around at this time of year is the Red Tailed Bumblebee, B. lapidarius. There’s a nest under the orchard wall around 50 metres away, and it wasn’t surprising to see a few workers of this very smart Common Carder BeeRed Tailed Bumblebeeand relatively short tongued species around the nectar rich area where I was snapping. My identification skills start to go awry at this point, however. Apparently the key difference between B. hortorum, the Garden Bumblebee, and B. lucorum, the White-tailed bumblebee, is the yellow band at the bottom of the thorax. Tricky. I hope I’ve got this right. I think this is a White-tailed Bumblebee – i.e. without yellow band on thorax. White-tailed Bumblebee Common but endearing. This next lady, then, could well be B.hortorum, or a Garden Bumblebee worker. She is rather moth-eaten, but she does have a yellow band at the bottom of her thorax and, apparently, a very long tongue. If I’m lucky I can sex bumblebees, which you can do by looking at the antenna; long, round antenna mean a male. I might have some idea on bumblebee identification, but I know next to nothing about different hoverflies. I think I can only confidently name one of these. Like solitary bees I am astonished to find the vast number of native species – around 270 – Garden BumblebeeHoverfly 1and they are strong enough flyers that, like butterflies, we also entertain migrants. I’ve always been told their larvae have an insatiable appetite for greenfly, but it turns out that only about a third of them eat aphids. They’re interesting and attractive insects, though, and – surprise surprise – many are in decline as a result of habitat loss. I thought I’d add some to my gallery, as they frequented the Knapweed too. Hoverfly 2Hoverfly 4The meadow will start to look tired in a little while, and once some of the Knapweed goes to seed I’ll cut it. I don’t need the hay, so it doesn’t matter if it’s all stalky. The sheep are already running through some sections of it where there’s nothing left to flower to save me the effort of cutting it. In the meantime I’m looking forward to more coffee breaks out there in the sun, and enjoying it as much as the birds seem to be. Hoverfly 3I haven’t even begun to describe the Flycatchers, finches, martins and swallows… I’m just amazed by how much there is going on in such a small area, and equally amazed at how easy it has been to establish such a rich habitat. Immensely satisfying – go on, give it a go!

The Bonzer Bee Box

Bee Box for Solitary BeesLate last summer we made a a box for solitary bees out of an old wooden wine box and assorted bits of bamboo, blocks of wood and elder stems, topped off with some wire to stop the woodpeckers pulling it to pieces. We followed the guide at foxleas.com, which was very helpful and led us to a rather different design than many of the commercially available boxes. Red Mason Bee What started off looking like a piece of wacky sculpture has now turned into a busy bee house. In contrast to bumblebee boxes, a sensibly designed and sited solitary bee house seems like a surefire winner and it seems like a really good wet afternoon project for the children. You can buy interesting ones too.
Miner bees have stoppered around a quarter of the tubes with mud already, with their eggs laid snugly inside with stores – these are the chaps I’ve been watching gather building supplies by the pond. I think there are also leafcutter bees in residence too, but I’m struggling to identify them and the more I struggle the more different species I notice. Help! My bumblebees are quite good now but these defeat me utterly. There are apparently over 200 solitary bee species in the UK (!), which is pretty testing for a non-specialist – is there anyone out there who can help me identify these three?

Mason Bee
?

Osmia rufa
Red Mason Bee (Osmia rufa)?

megachile
Another Red Mason Bee?