In this article I hope to pin down some facts about DCAs starting with the fundamental questions:

• • What
  • Who
  • Why
  • When
  • Where
  • How

What?

A Drone Congregation Area (DCA) is all about sex.

It is a place up in the air where drones gather together and to which queens are attracted. The drones are in search of sex and the queens are hoping to find suitable genes for their offspring.

Who?

So who are involved?

Drones are male honey bees and on the surface it may seem that their sole purpose is to find a queen and mate with her; they have other roles in the hive but we won’t go into that here.

Interestingly, of all 3 castes – they take the longest to emerge and mature. It would be logical to assume that it takes much longer to reconstruct a drone from the metamorphosal soup than either workers or queens because they are such big chunky chaps. They have those great big, meet-in-the-middle eyes and muscle packed thoraces to enable them to see, and fly long distances.  Or for a long time. There is a difference.

Queens

However, virgin queens – which are larger than a worker but smaller than a drone take the least time to mature. But then they are just egg-laying bimbos with pheromones. Or perhaps they are brighter than that.

Virgins are very svelte and streamlined with long wings and when freshly emerged they seem built for action.  Only when they are mated and in full lay does long distance flight seem unlikely. But how far do they actually fly?

Why?

Why go to the bother and risk of flying out from the safety of the hive to mate on the wing at the whim of predatory birds and squally summer weather?

Drone congregation areas are an evolved mechanism:

• to avoid inbreeding;
• to ensure the selection of the stongest drones.

Inbreeding

Here is an interesting fact – Gudrun Koeningen and her team (who did much research into this subject)  found that if they threw pebbles up into an overhead DCA, drones would form comets to chase the moving object but this chasing behaviour could not be observed outside the DCA.

Something about the DCA seems to switch on this chasing behaviour – and what it leads to – because drones do not seem to be interested in chasing things outside of the DCAs. Nor do they chase virgins round the hive.

A bit like young men at home – they don’t go chasing and mounting their sisters – or their mothers for that matter.   Quite apart from the threat of two-headed offspring, the urge doesn’t seem to arise, so to speak.

However, take them away from home and mix them all up together… the boys get competitive and they get horny.

Selection

‘Fitness’ in an evolutionary sense refers to those individuals best fitted to a given environment.

The drone comet is a competition or test evolved to select the strongest and fittest drones from the DCA – the winners get to mate with a queen and pass their genes on to the next generation. Such tests help ensure the survival of the species.  Critics of Instrumental Insemination see this as a vital  mechanism which is missing in drone selection. They have a point.

When?

Drones leave the hive after lunch on warm sunny days. Gudrun found that temperatures of 25 degrees C or above and when the weather was close, with thunder possible were most favourable.

Where?

Now here’s the crux.

Gudrun Koeniger seemed to have no difficulty finding DCAs in the Alps, given the right sort of weather she knew where to look. Mostly  she had the right sort of weather and lo and behold there were DCAs humming overhead. That’s continental Europe for you – large land  masses just tend to have more settled predictable weather. Islands in the Atlantic just don’t. In Ireland – the only predictable thing about summer weather is the unpredictability.

To find a DCA – strap a virgin queen to the end of a very long pole then walk her into a likely area. If there is a DCA – a comet of drones will come to her very quickly. Beowulf Cooper used to attend the annual Gormanston Summer Beekeeping Course in Co.Meath, Ireland and would often take to the grounds with a ripe virgin on a stick and locate a DCA there. Students were seldom disappointed – but as you will know if you attend Gormanston on a regular basis – the weather is almost always warm, sunny and dry.

In other parts of Ireland, despite the knowledge that DCAs persist over centuries, in this part of the world and in the the UK DCAs have been more elusive.

The Vicar of Selborne

England’s first Ecologist – Gilbert White, the Vicar of Selborne wrote the ‘Natural History of Selborne’ which was first published in 1789.

In it he described and recorded many observations of the wildlife of Selborne including  the presence of what had to be a DCA at Selborne Common:

“There is a natural occurance to be met with upon the highest part of our down on hot summer days, which always amuses me much, without giving me any satisfaction with respect to the cause of it; & that is a loud audible humming of bees in the air, tho’ not one insect is to be seen. This sound is to be heard distinctly the whole common through, from the Money-dells, to Mr White’s avenue-gate. Any person would suppose that a large swarm of bees was in motion, & playing about over his head. This noise was heard last week on June 28th.”

It can still be found today – over 300 years later – but only sometimes! Probably something to do with the weather.  To cope with the unpredictability of the weather here in ‘these islands’, the bees have evolved to sieze the moment. They will fly out into the landscape whenever and wherever the temperature, wind, topography and aspect interact to provide the right conditions. DCAs here at the wet end of Europe are moveable feasts.

How does all this work?

Fuel comes into it.  A drone fuelling up for a flight can only carry enough nectar to keep him airborne for 25-30 minutes. He cannot fill up from flowers – he has to be fed – so the distance he can fly from home is limited because he has to leave himself enough fuel to get home – in case he doesn’t get lucky and die. The chances of him accomplishing his mission are slim so he has to plan to return home. I should say here – he does no planning – this is behaviour that has evolved over millions of years.

So here if you look at his energy budget this tells us something about the distance a DCA can be from home.

Here are two scenarios:

• Say he flies out 10 minutes and 10 minutes back… that only leaves him 5 to 10 minutes cruising time. That doesn’t make much sense if you bear in mind that his chances of getting lucky are about as good as winning the lottery. Drones need to maximise their time in the DCA.
• Alternatively, if he flies out for only 5 minutes then his return journey is another 5 minutes leaving 15 to 20 minutes cruising around in the DCA waiting for a virgin to pass by. That makes more sense.

So it needs to be close by and if there are thermal currents so much the better – warm updrafts would help keep the drones in the air and conserve energy.

Mating Behaviour Studies in the Austrian Alps

Gudrun Koenigen et al intensively studied DCAs and honey bee mating behaviour in valleys in the Austrian Alps. During the course of their work the team got to know the location of all the DCAs in the study area and also all of the apiaries where bees were kept. They also perfected methods of netting drones within DCAs.

To find the origins of drones in the DCA was relatively easy – they would go to all the apiaries in the  morning – open the hives and mark drones – each apiary having a defining colour. Then, in the afternoons they would net drones in DCAs and count drones of each colour. This allowed them to conclude that drones would fly as much as 5km (3 miles) and only downhill (on the outward journey) – in the Alps anyway, drones do not fly uphill and that makes sense really – bearing in mind that honey bees are not creatures of the mountain tops.

In fact that makes sense here too – honey bees are not creatures of the hill so why go there. Assume then that drones fly out and head downhill along a linear feature such as a hedgerow or a stream. Where they go from then on must be evolved guesswork or is it something deeper, more intelligent, something which might explain why it takes so much longer to assemble a drone from the metamorphosal soup.

Who flies furthest, virgin or drone

Various experiments have showed that drones prefer DCAs closest to home but queens prefer the furthest away. So long as all drones and all queens employ the same strategy this is a mechanism which would avoid inbreeding but it raises the following questions.

Q. The queen has to get home but the drone doesn’t, so wouldn’t it  make more sense if she chose one closer to home and he went further away?

A. Once the queen enters the DCA of her choice – she is very quickly  serviced and can head for home. We know virgins may take a few mating flights so she can go back for another go if need be.

Q. The drone has all the muscle – couldn’t he fly further?

A. Drones may have more muscle but if they choose one closer to home they can stay there for longer.

Q.  A virgin must have to pass quite close to DCAs on her journey – might she get jumped?

A. Drones don’t chase virgins outside DCAs  and avoiding them might not be so difficult – we know there is a loud humming.

Finding DCAs

So, mark your apiaries on a map and draw 5km circles around them – that will tell you how far your drones will fly. Then look at the contours, think like a drone, fly down a line then follow your imagination.

In this modern world of ours there are things like roads, carparks and ploughed fields. All of them are dark surfaces. The energy of sunlight is reflected from dark surfaces as heat energy and warm air rises in columns from such areas as thermals. Thermals are utilised by hot-air balloons, vultures and hang gliders as an upwards boost against the downward pull of gravity. They are also chosen by drones for congregation areas.

A friend of mine once pointed to an area above a shimmering black carpark near his apiary and said there’s a DCA right there. How do you know says I. Dead drones all over it says he. You have to laugh don’t you?

Roads and carparks stay put but ploughed fields can turn up anywhere.  All of these modern features could draw drones away from what might be considered traditional or historic DCA sites and add to the reasons why they seem to be so elusive. An oversupply of thermal sites might also cause a situation where the numbers of drones per DCA are lower than they should be and could be yet another reason why poor queen mating is often such a problem.

There are theories out there that drones are somehow tuned into ‘Ley lines’ and that DCAs are often associated with prehistoric sites such as barrows or standing stones. That’s an exercise bone for the imagination if ever I heard one.

Barrows or standing stones are often on hilltops. Sunlight slanting in on the slope of a little hill can cause thermal columns to rise on a sunny afternoon. But try and imagine how prehistoric man might interpret such areas where, summer after summer, could be heard a loud overhead buzzing accompanied by sprinklings of large dead flies. That’s an exercise bone for the Neolithic imagination to chew on I think and you can imagine how it might result in the erection of large stone or circle of stones to ward off evil.

Click here for more about Drones

Click here for more about the Queen

Click here for more about queen bees

Click here for a free downloadable copy of Gilbert White’s book

Copyright © Beespoke.info 2021.  All Rights Reserved.

But before you  test the bees – always check she’s not in the supers! Even with an excluder in place, it’s surprising how often the queen can find her way upstairs and build a lovely brood nest in the honey.

Also consider just how long it takes for the bees to make a new queen cell from scratch, for the virgin to emerge, to mature, to get mated and to start laying. Remember, the weather has a lot to do with how quickly she can get mated.

Look at the diagram below and use it to manage your expectations. Don’t panic till week 6.

If you still think your bees have no queen – here is the test for queenlessness:

Queenlessness test

• Make absolutely sure there aren’t already queencells tucked away somewhere;
• Add in a frame of young larvae (<3 days old) from a different colony.  Nurse bees will sometimes eat the eggs of other bees but will happily draw emergency cells from small larvae;
• Come back in a week;
• If there are no queen cells they either have a queen or they think they have a queen, there is a difference; they could have a drone laying queen or laying workers (see below);
• If there are queen cells – they are queenless;
• Remove the queen cells and the colony is now hopelessly queenless and should be ready to accept a new queen using the method of your choice.

Drone laying queens

A drone laying queen is a queen that didn’t mate properly and her spermatheca has run dry. That’ s the little vessel inside herself where she stores the sperm from when she got mated – each time she lays a worker egg, she fertilises it with sperm from the spermatheca.  If it runs dry she can only lay unfertilised eggs and these, of course, become drones. Because she lays drone eggs into worker cells the drone larvae rapidly outgrow the cells and  the result is horribly distorted comb.

If you have a drone laying queen you will have to find her and kill her.  Once you’ve done that you can introduce a new queen.

Laying workers

When a hive has been queenless for a while, the broodless state causes one, or some, of the younger workers to start laying eggs. Of course these workers have never mated so can only lay unfertilised eggs which will hatch as drones.

The egg laying pattern of laying workers tends to be crappy and there may be several eggs scattered in each cell.

The best thing to do in this case is to add in one or two frames of young larvae (from another hive). This tends to rewind the situation, the laying workers are ‘reset’ and  you can introduce a new queen.

Click here for how to introduce a new queen

Click here for how to introduce a queen using the matchbox method

Click here for how to introduce a queen using the postal cage

Click here for how to introduce a queen to an Apidea

Copyright © Beespoke.info 2019.  All Rights Reserved.

Perfect supersedure is where the old honey bee queen obligingly remains in-situ, laying to the best of her abilities, until the new queen is up and running – before gracefully fizzling out.

This is a sought-after trait for obvious reasons and if you find it in one of your colonies you should definitely factor it in to your bee improvement assessments. Click here for Bee Improvement and to download Assessment sheets.

Here are some fuzzy photo’s of a perfect supersedure in one of our hives yesterday (20.5.19)

Click here for Fighting Queen Bees

Click here for Piping Queen Bees

Click here for How to Improve your Bees

Click here for more about the life cycle of honey bees

Click here for more about the Queen Bee

Click here for Swarm Control

Click here for Swarm Prevention

Copyright © Beespoke.info 2019.  All Rights Reserved.

Click here for updated list of Irish Native Honey Bee suppliers

Click here for more about the Native Irish Honey Bee

For us Celts it is also the first day of Spring but you Saxon Dogs will have to wait till March 20th!

For the bees though – read on:

There are a few hardy plants that flower in early spring but only the willow (Salix spp) can produce enough nectar for a small surplus and  only in a very warm spring.

Of course the Native bee will forage at lower temperatures and is better able to take advantage of what little fresh nectar and pollen is available.

Until today – I’ve never seen a bee on a dandelion and didn’t really believe they found them interesting but here’s the evidence they do and the pollen loads are yellow:

The table below shows some possible bee flowers for February. Green lines are Irish natives. Click it for a better view:

Click here for March Bee Flowers

Click here for April Bee Flowers

Click here for May Bee Flowers

Click here for June Bee Flowers

Click here for July Bee Flowers

Click here for August Bee Flowers

Click here for September Bee Flowers

Click here for October Bee Flowers

Click here for November Bee Flowers

Click here for more about Gorse

Click here for a general seasonal guide to important bee flowers

Click here for photos of pollen load colours

Copyright © Beespoke.info, 2017.  All Rights Reserved.

The four quarter days are:

• Lady day or the Feast of the Annunciation 25th March;
• Midsummer’s day around 25th June;
• Michaelmas 29th September;
• Christmas 25th December – lest we forget. Fat chance.

They all approximately coincide with either an equinox or a solstice.

Equinoxes

An equinox is when day and night are of equal duration. There are two of them – spring and autumn:

• Spring equinox 21st March;
• Autumn equinox 23rd September.

Solstices

As for the solstices there are two of these too – summer and winter.

• Summer solstice (longest day and shortest night) 21st June;
• Winter solstice (shortest day and longest night) 22nd December.

Christmas

Nobody knows the day or the month when Jesus Christ was actually born. However, the Feast of the Annunciation falls on the 25th March which is when Christians celebrate the day Gabriel called on Mary to tell her she was to be the mother of the son of God.

Imagine that!

Christmas is exactly 9 months after the Feast of the Annunciation. That’s biology for you.

Christmas also coincides approximately with the Winter Solstice on 22nd December. Also known as The Shortest Day. Now there’s cause to celebrate.

Christmas Traditions

You don’t need me to tell you about the ‘traditions’ of Christmas. Suffice to say, it is cruel that we have to bear it in the middle of the darkest, wettest and most depressing time of the year. It’s enough to push you over the edge!

We can never really know what Jesus might think about Christmas traditions, However, we do know what happened when he discovered the merchants had set up shop in the temple, so we can guess:

‘But what about the bees?’ says you…

Us beekeepers are fortunate because there is a lot of stuff out there to be getting on with at christmas.

Treat them

The bees should have been fed and treated for Varroa after the honey was extracted at the end of summer. However, midwinter is the time when the queen bees should be off lay and there should be a short broodless period which is ideal for a backup treatment with Oxalic acid. I say should be because it is not always the case especially in a mild year or where they ivy bloomed late. So long as there has been a bit of cold weather – below 15 degrees – and a decent interval since you last saw yellow ivy pollen going in to the hives – Christmas should be perfect.

Click here for how to do that.

Click here for more about Oxalic acid for Beekeepers.

I should add that midwinter treatment may not be necessary if you are confident that the conditions in autumn were good enough to allow your thymol/MAQS to work properly.

Feed them

While you are out there – check the feed status of your bees. Heft the hives to assess the weight and if they seem light put some fondant on. It won’t do any harm and if they need it later – it’s there.

If the bees seem weak and are clustering close to the top of the frames you could choose to remove the crownboard and place the fondant directly onto the bees where they will find it easily. If you do this – add an eke and pack the space around the fondant with old jumpers, sacking or some other cosy stuff.

Don’t put pollen substitute on yet – too early – wait for February.

Apiary Watch

Make sure the hive roofs are weighted down with stones or tied with ropes – winter has hardly started and there could be gales. And there could be animals.

Maintenance

Mend broken equipment. Treat spare boxes if they need it. Make up new stuff but don’t put wax into new frames till spring or it will just lose its fragrance and go all crispy then the bees won’t work it properly – they’ll draw all that abstract stuff with holes and buttresses.

All your equipment, supers, spare brood boxes etc could all do with a good scrape down – propolis flakes off well in the cold weather.  Save all the little bits of beeswax you will be amazed how it mounts up.

Click here for how to tackle your beeswax mountain.

Strip down old frames with black, knackered or holy wax. Holy wax is comb with holes in it. Burn the really black horrible wax – use if for lighting fires that’s the only thing it’s good for.

Save the paler, cleaner wax and render it:

Click here for how to render beeswax.

Then do something interesting with it but take care not to set fire to yourself:

Click here for beeswax polish recipe

Click here for beeswax lipbalm recipe

Click here for beeswax handcream recipe

Click here for candle making

Click here for soap making

Wax Moth

If you are storing used brood frames and you know you have a  wax moth problem you might like to take this opportunity to treat them with acetic acid. Acetic acid is not the stuff you put on your chips – treat it with respect.

Click here for how to do that thing

There is also a biological control agent from Vita which uses a micro-organism to attack wax moth.  The product is called Certan and the micro-organism is called Bacillus thuringiensis.

Click here for Certan information

Christmas Forage

There is very little floral forage out there for the bees at Christmas. This year there is quite a lot of gorse in bloom. In some years there may be the dregs of the ivy. Also some winter garden plants such as Mahonia or even snowdrops.

• Ivy pollen is yellow
• Gorse is orange/brown
• Snowdrops pollen is orange/brown too
• Click here for more about ivy
• Click here for how to take a crop of ivy honey.

Happy New Year!

Copyright © Beespoke.info, 2017.  All Rights Reserved.

Pollinator Decline

Pollinators, including honey bees, are in decline all over Europe due to habitat loss, climate change and modern  agricultural practices. All the usual culprits. This is fact.

Anybody in doubt about that should cast their minds back to the good old days when car windscreens would be so plastered with crushed insects – regular stops were needed to scrape them off.

Mind you, cars were rather less streamlined then and a bit more – er – ‘boxy’:

Einstein

Einstein said, “If the bee disappeared off the surface of the globe, man would have only four years left to live“.

They now say he probably didn’t say that at all but then they would wouldn’t they.  Whether he said it or not – the bleak nugget of truth in that sentence seems to have reached most people.

Threatened Pollinators

Ireland’s wild pollinators include 20 species of bumble bee, 77 solitary bee species plus 1 species of honey bee. All of these are entirely dependent on flowers to exist so it is bees that carry out most of the pollination services.

33% of these are threatened with extinction.

Other pollinators include flies, butterflies, moths, wasps, ants, beetles.

Between them, their pollination services are thought to be worth €153 billion worldwide and at least €53 million in Ireland.

In response to the very real threat to these insects and (god forbid) the economy, many countries including Ireland have put in place plans to attempt to reverse the trend of pollinator loss.

Ireland’s Pollinator Plan 2015 – 2020

Biodiversity Ireland with Trinity College Dublin and a 15 member steering panel of experts have devised a 5 year plan to address pollinator decline and protect the pollination service these insects freely provide to agriculture, horticulture and the countryside in general.

 Objectives

The plan has 5 objectives:

• Making Ireland pollinator friendly.
  Pinpoint things that can be done on farmland, public land and private land, to create an interconnected network of wildflower-rich pollinator-friendly habitats.
• Raising awareness of pollinators and how
  to protect them.
  Increase awareness of the importance of
  pollinators and the resources they need to survive.
• Managed pollinators – supporting beekeepers and growers. To achieve healthy, sustainable populations of managed pollinators that can play a full role in delivering pollination services.
• Expanding our knowledge of pollinators and pollination service Increase research and knowledge to find the best and most cost-effective ways to protect pollinators.
• Collecting evidence to track change and measure success Survey pollinators and monitor change to ensure the Plan is working.

Eighty one actions have been indentified to achieve these aims and have been shared out among sixty-eight governmental and non-governmental organisations which have agreed to support the plan.

The recommended actions include:

Hedgerows

Planting new hedgerows with native species such as hawthorn, hazel, willow and blackberry etc. Old hedgerows should be maintained properly and cut less often. Vegetation at hedge bases should not be sprayed so wild flowers are conserved.

 Wildflowers

Should be encouraged along hedges, lanes and field corners. Buffer strips containing native wild flowers should be planted along field margins and cut between September and April only. Further management practices can include grazing to conserve and improve these areas.

Nectar and Pollen rich shrubs and trees

Planting of willow, hazel, hawthorn, horse chestnut and blackthorn in hedges and field corners, parks, schools etc.

Nesting Areas

Tussocky grass and nettles provide nesting areas for bumble bees. Bare uncompacted ground for solitary bees.

The Other Bits

I added the photo below to demonstrate just how much land is not hedgerow or hedge base. When these fields are planted with rye grass, rye grass, rye grass  or in modern day crop rotation of barley, barley, barley, wheat, barley, they are as about as useful to bees and other pollinating insects as these flooded fields:

Funding

The plan points to government initiatives that are already in force and it is hoped that communities and local authorities will formulate projects and seek funding from local and national government. There is also the possibility of funding from Europe.

Honey Bees

All of these measures will help honeybees and that is to be welcomed. However, apart from the spectre of mapping and education on diseases the plan is a bit short on specific help for honey bees. All beekeeping associations already provide education on diseases.

The plan describes honey bees as being ‘domesticated’ or ‘managed’.

Domesticated

Before the Varroa mite, which came in with imported bees in 1999 or thereabouts, the honeybee lived as wild as all the other Irish pollinators. Until recently it was thought to be extinct as a wild species but recent research has shown that Ireland’s native bee – Apis mellifera mellifera is in fact alive and kicking in the wild. Presumably it is adapting to cope with Varroa – perhaps becoming swarmier.

Imports

It is a shame that no steps are suggested in this plan to prevent further imports of foreign bees and the exotic pests that come in with them. That would have helped to protect the honey bee.

Managed

Also the plan says this, “The needs of managed honeybees are very different to those of wild pollinators. Beekeepers can move colonies to where forage sources are available, and can provide extra resources over the winter.”

Well, that’s just not true. The majority of beekeepers in Ireland are hobbyists – that is they have a couple of hives in the garden and no other apiary.

To move bees, you need to have somewhere to take them and you need the know-how to move them. It’s not a walk in the park you know. Moving bees is stressful for both bees and beekeepers. It is not for the fainthearted – it is ticklish, potentially dangerous and certainly not for the novice. But that’s for another post.

Conclusion

Much is made of planting wildflowers but there are wildflowers and there are wildflowers. Anyone thinking of sowing wildflowers should try and get Irish natives. Foreign wildflowers evolved with foreign insects and may not be appropriate here.

Irish wildflower seed is available from Sandro Cafolla – more info on his website www.wildflowers.ie

Click here for Biodiversity Ireland and the Ireland Pollinator Plan

Click here for Irish Wildflower seeds

Click here for Hedgelaying Ireland

Click here for more about Bees and Climate Change

Click here for Bee Trees – Hawthorn

Click here for Bee Trees – Hazel

Click here for Bee Trees – Ivy

Click here for  Bee Trees – Horse Chestnut

Click here for  Bee Trees – Sycamore

Click here for Bee Trees – Willow

Click here for Bee Trees – Lime

Click here for Bee Trees – Poplar

Copyright © Beespoke.info, 2015.  All Rights Reserved.

From an ecological point of view there are at least 3 reasons:

• Honeybees have evolved in tandem with certain flowers and they have adapted to facilitate each other;
• One bee is able to rapidly communicate the location of a pollen/nectar source to the whole hive and an army sets out;
• The bees then concentrate faithfully on that flower species until the pollen runs out or the nectar dries up, at which point the job of pollination is accomplished.

These features obviously make the honey bee important from an agricultural/commercial point of view. In addition, hives of bees are mobile and can be moved from crop to crop – an arrangement which can suit bees, farmers and beekeepers so long as everyone has a bit of respect. Wouldn’t that be great?

But some detail:

Evolution

In the beginning there was the wind…

The earliest seed-bearing plants were randomly pollinated by wind-borne pollen which would be caught on droplets of a sticky exudation oozing from their ovules. Because of the hit and miss nature of this method of pollination massive amounts of pollen need to be produced in the hope that at least some of it will find its mark. This method is still used by conifers.

Then came the insects…

It is thought that eventually sap-sucking or resin-browsing insects were drawn to dine on the exudation. The effects of this were beneficial to both parties – the insects were introduced to pollen as a  new source of protein and as they moved around from plant to plant they carried pollen with them and pollinated as they went. Plants pollinated in this way needed to produce less pollen than those still relying on the wind. Insect pollination was also more efficient so these plants were able to produce more offspring and the trait persisted.

Co-evolution

As long as such associations are mutually beneficial, their continuance is at least assured and there may even be further co-evolution. Each step along the co-evolutionary pathway creates a more fruitful relationship although things are more prone to disaster.

Over-dependency

Occasionally a plant may devise an almost perfect method of manipulating an insect for pollination purposes but such cases are so complex they tend to involve a single species of insect. One of the best examples of this is the flower of the orchid Ophrys speculum which looks enough like the female of a certain bee species (not Apis mellifera) to entice pollen coated male bees to mate with it and thus pollinate it in a novel way. While this may be a highly successful method of pollination, the future of the orchid becomes tied in very closely to that of the bee; if the bee species should decline or even become extinct, perhaps due to habitat destruction or a surfeit of exhausted males, then the orchid will be doomed to follow.

Honey bee adaptations

The honey bee has not yet been so tightly hemmed in by co-evolution and they remain relatively broad spectrum pollinators. However they have evolved certain adaptations that suit them for their job such as tube-like mouthparts for reaching down into the throats of flowers in search of nectar and the hairy body which is the ideal surface to which pollen grains will easily cling. There are also pollen baskets but these are designed not for the passing on of pollen but to collect the bee’s share to take home to the hive.

Bee flower adaptations

Plants, for their part, have adapted their flowers to attract bees – all sorts of bees. They tend to have  brightly coloured petals, usually blue or yellow, with a landing platform of some sort. The petal markings may include honey guides which are designed to tell the bee where the nectar is. The nectaries are tucked away near the base of the corolla tube, where only the tube-like mouth-parts of a bee can reach and inaccessible to the chewing of beetles.

There are also cunning floral booby traps designed to manipulate the insect pollinators:

• Scotch broom – Cytisus scoparius  is spring-loaded to burst open when a bee lands, the curved stamens and stigma arching over the bee; the stamens to press pollen onto its back and the stigma hoping to pick up some suitable pollen placed there by another broom plant.
• Gorse (Ulex europaeus) is also spring loaded but in this case the stigma and stamens burst from the floor of the flower, hoisting the bee into the air. Here the target must be the bee’s belly.

• Rosemary officinalis is not sprung, but has stamen and stigma strategically arranged to arch out of the upper part of the flower in such a way as to brush the bee’s back.
• Himalayan balsam or Impatiens glandulifera has stamens situated above the entrance of the flower so as the bee pushes its way in – a streak of white pollen is plastered onto its thorax

• Meadow sage or Salvia pratensis has a carefully placed foot-plate which is hinged to the stamens, when the bee treads on the foot-plate the stamens swing down from the roof of the flower stamping pollen onto its back.  The stigma, meanwhile, extends from the upper lobe of the flower and lengthens with age so that bees entering an older flower brush against it on the way in so delivering the pollen. Presumably this age-related lengthening is a mechanism to avoid self pollination. Click this fabulous photo below for a close up of Salvia pratensis pollination in action – not mine and not a honey bee – all credits to Wikimedia.org

So a day in the life of a honeybee can be quite a circus, hoisted into the air one minute and thumped on the back the next.

Honey bee exclusion

Some flowers have evolved to exclude honeybees in favour of other insects.

A common method of exclusion is by having corolla tubes too deep for the bees’ elongated mouthparts and these are butterfly flowers. An example would be honeysuckle (Lonicera periclymenum).  Unimaginative though – don’t you think? How about weight activated trapdoors, ejector seats or that old favourite – a boxing glove on a spring.

However, exclusion can backfire. Some insects are clever enough to chew a hole into the corolla tube to access the nectaries bypassing the pollination step altogether. Honey bees will sometimes use these access holes too.

Another exclusion method is an open door policy. Primitive flowers such as composites (daisy-like flowers) are open to all and sundry. These are little visited by honeybees as they are not mixers by nature and dislike competition.

Wild carrot (Daucus carota) flowers are white composites but they sometimes have one small red flower in the centre (above).This is thought to attract flies who think the little red dot is another fly and flies are great mixers. Just look at horse muck!

Communication

The foraging force of any one hive may number 25 thousand and they will cover the area within a radius of 3 miles from the hive  in search of nectar and pollen. When they find a good source, they become very purposeful, they load up with pollen and/or nectar, then they go back home to the hive. Once home they will hand out samples of what they have found and dance enthusiastically to tell everyone where it came from – how far, how much and which direction. Bees that respond to the dance and go out and find the source are said to be ‘recruited’. For bees, this means they will go out after this species of flower until either they die or the source does. Communication means that a chance discovery by one bee will lead to thousands and thousands following on and obviously the more bees the quicker will be the pollination.

Good Youtube video on dancing bees here:

Fidelity

The fidelity bees show for a single species helps pollination in several different ways.

• Once they have been discovered by the bees, increasing numbers of bees are recruited to forage on that species moving from flower to flower depositing pollen as they go.
• They will continue to visit until either the nectar dries up or the weather changes. They make the most of spells of good weather.
• When the bees return to the hive they all tumble around together in the hive, passing pollen from bee to bee as they brush shoulders. This increases the likelihood of cross pollination as bees will then be carrying pollen from several individuals of the same species.
• Focussed attention means plants need not produce so much pollen.

Mobility

From a commercial/agricultural point of view, hives of bees can easily be moved from crop to crop where all of the above apply. Bees are regularly employed to pollinate crops of oil seed rape, borage (star flower) and top fruit in the UK.

Meanwhile in the USA, fruit farmers and beekeepers have evolved a highly efficient annual migratory existence following a variety of crops west to east by the truckload across the country. They are paid for their services as pollinators and of course there is the honey too. Crops they are paid to pollinate include apples and pears, cherries and almonds, melons, cucumbers and squash, cranberries and sunflowers. For honey there are orange blossom, alfalfa, California buckwheat, blueberries, Brazilian pepper, palmetto, basswood, clover and gallberry to choose from.

It could be said that they have, between them, created a specialist relationship like the delicate orchid/bee example above. One that is very focussed and even efficient but also very vulnerable and we’ve seen what can happen with the disastrous Colony Collapse Disorder.

Here in Ireland, while farmers will welcome beekeepers onto their land when they are growing oilseed rape or apples etc there are few who will pay the beekeeper to move.

But read on…

The Future

The drive towards increasingly intensive agriculture is accelerating. Each year, more hedgerows and patches of scrub are ruthlessly wiped off the landscape and mixed meadows  reseeded with rye grass. Habitat destruction causes the extinction of wild pollinators and this may lead to an increase in demand for mobile beekeepers here but we should know where that stuff leads.

But always look on the bright side of life – that’s my motto!

Click here for the mechanics of Pollination

Click here for more on Gorse Pollination

Click here for more about Himalayan Balsam

Click here for Ireland’s Pollinator Plan 2015-2020

Sources

Attenborough,D.  Life on Earth – A Natural History. BBC, William Collins and Reader’s Digest. 1979.

Campbell,N.A.  Biology – Second Edition. The Benjamin Cummings Publishing Company Inc. USA. 1990.

Mairson,A.  America’s Beekeepers – Hives for Hire. In National Geographic Vol. 183 No. 5. 1993.

Raven,P.H., Evert,R.F. & Eichhorn,S.E.  Biology of Plants. Worth Publishers Inc., New York. USA. 1986.

Copyright © Beespoke.info, 2016.  All Rights Reserved.