Category Archives: Principles

Botulism

Do not feed to infants

Do not feed to infants

I was recently asked, Why can’t you give young babies honey?

You can.

But just because you can doesn’t mean you should.

And on this point the NHS guidelines are very clear. You should not give honey to babies under 12 months of age because there is a risk that they might get botulism.

Bacteria, toxins and Botox

Botulism is a serious, sometimes fatal, disease caused by infection with a bacterium called Clostridium botulinum. As it grows, C. botulinum produces neurotoxins which cause a flaccid (floppy) paralysis and can result in respiratory failure. About 5-10% of cases are fatal, but infections thankfully very are rare.

Symptoms include fatigue, weakness, blurred vision and difficulty speaking and swallowing. The paralysis is ‘descending’, generally starting in the head and neck, then moving to the shoulders, arms, chest and lower limbs.

Botulinum toxin

Botulinum toxin

Unusually for a bacterial infection there is no fever. This reflects the fact that there’s probably only limited bacterial growth (which typically induces fever) and the potent neurotoxicity of the botulinum toxin. This toxin stops the release of the neurotransmitter acetylcholine from the nerve endings, thereby causing paralysis.

Botulinum toxin is one of the most acutely lethal toxins known. The lethal dose depends upon the route of administration, but is between 1.3 and 13 ng/kg 1.

Remember, botulinum toxin is the active ingredient in Botox.

No thanks. I’ll stick with the wrinkles 😉

Botulism cases in the UK/Europe

Botulism is a notifiable disease. Consequently, we have good data on the incidence of botulism in the UK and Europe. In 2014 there were 91 confirmed cases in the EU, with 14 cases reported in the UK between 2010 and 2014. Other than injecting drug users, a significant proportion of the cases are in infants – see below.

C. botulinum is widespread in the environment and infection usually occurs by ingestion of improperly prepared food e.g. undercooked or improperly canned foods, in which the bacteria survives.

Clostridium botulinum

Clostridium botulinum

The bacteria grows in the absence of oxygen and produces the toxin during growth. Although the toxin is heat-inactivated if properly cooked (over 85°C), the bacterium also produces heat-resistant spores during growth. These spores can withstand temperatures over 100°C for long periods and usually require both high temperatures and pressures to inactivate them.

As a consequence of this the spores are also very widespread in the environment … cue the Jaws soundtrack … just waiting to encounter the correct conditions to germinate and initiate a new round of bacterial growth (and toxin production).

Botulism cases in children

About a third of all cases of botulism are in the 0-4 age group. I’ve been unable to find a more detailed breakdown by age, but there have been 19 cases of infant (children less than 12 months old) botulism in the UK since 1978.

In many cases of infant botulism the source of the spores is unknown. However, other than well-documented cases of contaminated milk powder, honey is the only food regarded as a significant risk factor. About 60% of cases of infant botulism are in babies with a history of honey consumption 2 and, in several cases, epidemiological follow-up has confirmed that honey was the source of the infection.

Treatment is not with antibiotics as it’s the toxin that causes the symptoms, not the bacteria. Instead patients are treated with immunoglobulin (antibodies) specific for the toxin. These inactivate toxicity fast and recovery is usually complete, but can be protracted.

C. botulinum spores in honey

Oxygen inhibits the growth of C. botulinum. So do acidic conditions. Honey is acidic, with a pH of about 3.9, which is too low for the bacterium to grow. However, the spores remain viable at low  pH. It is this contamination of honey with C. botulinum spores that poses a risk for infants.

It is possible to microbiologically examine honey for contamination with C. botulinum spores. When this has been done, 6-10% of honey samples tested were contaminated, with contamination levels estimated at 5 to 80 spores per gram of honey. The infectious dose for a human is estimated at 10-100 spores 3.

So … much less than one teaspoon of contaminated honey.

Despite this, there is no requirement for honey to carry a label warning that it should not be fed to infants. Instead, the Food Standards Agency recommend honey carries a warning that it is unsuitable for children under one year of age.

Why is infant botulism so rare?

If up to 10% of honey is contaminated with C. botulinum spores, why are there not many more cases of botulism in infants? After all, European paediatricians have even been known  to recommend honey – a long-standing traditional solution – as a means of soothing crying babies4.

The intestine of the developing baby is full of bacteria – the so-called commensal microbiota – all competing to get established and to lead a long, happy and healthy association with their human host. The spores of C. botulinum have to germinate and establish an infection in the face of this competition and, usually, they fail. A likely possibility is that infant botulism only occurs in babies in which the commensal microbiota have not properly developed … either because they are so young, because broad-spectrum antibiotic use has prevented the development of the microbiota or for a pre-existing genetic condition.


 

Survival of the fattest

Winter bees have high levels of vitellogenin, a glycolipoprotein 1, deposited in their fat bodies which act as a food reservoir for the long winter.

These fat winter bees are essential for the successful overwintering of the colony.

Last week I discussed the major points that need attention for overwintering i.e. strong, healthy colonies with ample food in a weathertight hive.

This week I want to explore the relationship between colony strength, health – specifically with regard to Varroa and deformed wing virus (DWV) – and isolation starvation.

Isolation starvation describes the phenomenon where a small colony of tightly clustered honey bees gets isolated from the honey stores laid down in autumn, resulting – typically during protracted cold periods – in the colony starving to death.

Isolation starvation ...

Isolation starvation …

It’s both a pathetic and distressing sight. Bees, with their heads crammed into the bottom of cells searching for food, dying from starvation when literally inches away from capped stores.

Deaths and births

In temperate climates the winter is characterised by low temperatures and little or no forage for the bees. The queen usually stops laying sometime in autumn and starts again around the turn of the year. During the intervening period she may lay intermittently, but generally in limited amounts.

The fat bodied winter bees that are reared in late summer and early autumn are long-lived (about 6 months) and are responsible for getting the colony through the winter. They protect the queen, thermoregulate the hive and they help rear the brood raised in the autumn and through the winter.

In their absence – or if there are just too few of them – the colony will perish.

Winter bees do not all live for 6 months. The usual figure quoted is ~175 days 2. Some live shorter lives, some longer … up to 9 months under certain conditions.

Importantly, in studies I’ve discussed at length previously, high levels of DWV reduces the lifespan of winter bees. We know this because, in Varroa-infested colonies, researchers 3 have shown that the winter bees die off faster 4.

Live fast, die young

Winter bees with high levels of DWV don’t really live fast … but they do die young. In the studies above the average lifespan of winter bees was reduced by 20% in the colonies that died overwinter.

There are a couple of important things to note here. Dainat and colleagues were not looking at bees in the presence or absence of Varroa, or in the presence or absence of high or low levels of DWV. They simply looked at hives that succumbed in the winter or that survived, then measured DWV and Varroa levels. It’s a subtle but important difference. Their surviving colonies still had Varroa and DWV.

From analysis of hives that died or survived, and having marked known numbers of bees in late summer, they could determine the life expectancy of workers – in their surviving colonies it was ~88 days, in those that died it was ~71 days.

Healthy colonies

The gradual death of bees through the winter coupled with the reduced lifespan of winter bees with high levels of DWV explains why colonies need to be strong and healthy.

The following graphs are based upon modelled data 5, but show the influence of colony size and winter bee lifespan.

The first graph – the least important – simply shows the lifespan of bees. The graph plots the number of bees (on the vertical axis) in a population that die at a particular time (on the horizontal axis) after the start of the experiment. The blue bees have a longer average lifespan than the red bees 6.

Lifespan of winter bees

Lifespan of winter bees

In the following graphs remember that the blue bees are healthy, with low levels of Varroa and – consequently – low levels of DWV. The red bees are unhealthy and have high levels of Varroa and DWV.

Using this lifespan data we can look at the influence on the total number of winter bees in a colony (on the vertical axis) over time (horizontal). Imagine that the horizontal axis is the long, dark, wet and cold months of winter. Starting in early September and running through until late March.

Brrrr 🙁

Winter bee numbers in healthy (blue) and unhealthy (red) colonies

Winter bee numbers in healthy (blue) and unhealthy (red) colonies

It is clear, and of course entirely predictable, that the numbers of bees in the healthy (blue) colony are higher than those in the unhealthy colony at each time point. If the average lifespan is reduced (by disease) more bees will have died by a particular time point when compared with a healthy colony at the same timepoint.

Finally, consider that the shaded section of the graph represents the lower limit of bee numbers for viability. If the number of bees in the colony drops into this region the colony will perish.

Simplistically – and in reality – starting with similar numbers of bees a healthy colony will survive longer than an unhealthy colony.

Strong colonies

Using a similar approach we can also look at the influence of the average lifespan of winter bees on the survival of strong or weak colonies.

The following graph shows the numbers of bees in the colony over time for a strong colony (solid line) and a weak colony (dashed line) where worker bee lifespan is identical 7.

Winter bee numbers in strong and weak colonies.

Winter bee numbers in large (strong) and small (weak) colonies with the same average lifespan.

The shaded section of the graph again represents colony oblivion.

Large (strong) colonies take longer to drop below the threshold for viability and so – all other things being equal – will survive longer 8.

Mix’n’match

A strong colony with high levels of Varroa and DWV might actually survive less well than a weak but healthy colony.

Strong unhealthy colonies might survive less well than weak healthy colonies.

Large unhealthy colonies might survive less well than small healthy colonies.

In this graph the weak but healthy colony drops below the ‘viability threshold’ after the strong but unhealthy colony 9.

Winter bees and brood rearing

This is modelled data, but it makes the point clearly. Large and/or healthy colonies retain more of the all-important winter bees and so survive longer.

Simples.

The differences might not appear marked. However, for convenience 10 I’ve omitted the influence of winter bee numbers on the ability of the colony to rear brood.

If there are more winter bees, the colony is able to thermoregulate the hive better. It’s therefore able to keep any brood present warm. It’s therefore able to rear more brood.

As a consequence, the differences in bee numbers between the large or small, or the healthy and unhealthy, colonies will be much more striking.

Critically 11 the strength of the colony coming out of the winter is often the rate-limiting determinant for spring build-up to exploit early season nectar flows. Weak colonies develop less well.

Isolation starvation

Finally, returning to that pathetic little cluster of starving bees in the image at the top of the page. What is the relationship between colony health, strength and isolation starvation?

It’s now time to dust off my weak-to-non-existent Powerpoint skills …

Isolation starvation schematic

Isolation starvation schematic

Again, it’s straightforward. A large (strong) overwintering colony (A above) only has to move a short distance to access stores in midwinter. In contrast, a small (weak) overwintering colony has to move much further.

Consequently, small colonies become isolated from their stores during long, cold periods when the colony is clustered.

Prediction

Many beekeepers will be familiar with isolation starvation of overwintering colonies.

Most would explain this in terms of “very cold weather and the cluster was unable to reach its stores”.

Some would explain this in terms of “the colony was far too small to reach the stores when clustered”.

Very few would explain this in terms of “the Varroa and DWV levels were too high because of poor disease management last autumn. Inevitably most of my winter bees died off early in the winter, leaving a very small cluster of bees that were unable to reach the stores..

I suspect the real cause of isolation starvation is probably disease … specifically poor management of Varroa levels and consequently high levels of DWV in the colony.


Colophon

Herbert Spencer

Herbert Spencer

Another post, another poor pun in the title. Survival of the fittest encapsulates the Darwinian evolutionary principle that the form of an organism that survives is the one able to leave the most copies of itself in future generations. Darwin didn’t actually use the term until the 5th edition (1869) of his book On the origin of the species. Instead, the phrase was first used by Herbert Spencer in 1864 after reading Darwin’s book. Whilst ‘survival of the fittest’ suggests natural selection, Spencer was also a proponent of the inheritance of acquired characteristics, Lamarckism.

They think it’s all over!

We’re gently but inexorably segueing into early autumn after an excellent beekeeping season. The rosebay willow herb is almost over, the farmers are busy taking in the harvest and colonies are – or should be – crowded with under-occupied workers.

Rosebay willow herb

Rosebay willow herb

Drones are being ejected, wasps are persistently looking for access and there’s a long winter – or at least non-beekeeping period – ahead.

There’s a poignancy now in being in the apiary conducting the last few inspections of the season. Only a few short weeks ago, during late May and early June, the apiary was a scene of frenetic productivity … or complete turmoil, depending upon your level of organisation or competence.

Now there’s little activity as there’s not much forage available.

Colonies are busy doing nothing.

The most important time of the season

But that doesn’t mean that there’s nothing to do.

Rather, I’d argue that late August and early September is probably the most important period during the beekeeping year.

However well or badly the season progressed, this is the time that colonies have to be prepared for the coming winter. With good preparation, colonies will come through the winter well. They’ll build up strongly in spring and be ready to exploit the early season nectar flows.

In Fife, this is about 8 months away 🙁

This explains the poignancy.

There are some colonies inspected last weekend that probably won’t get properly opened again until mid/late April 2019. Queens I saw for the first time in August won’t get marked or clipped until next spring 1.

Au revoir!

Spot the queen ...

Spot the queen …

To survive the winter and build up well in the spring the colony has few requirements. But they are important. A lack of attention now can result in the loss of the colony later.

To appreciate their needs it’s important to understand what the colony does during the winter.

Suspended animation

Honey bees don’t hibernate in winter. In cold weather (under ~7°C) they cluster tightly to conserve energy and protect the queen and any brood in the colony.

At higher temperatures the cluster breaks but they largely remain within the hive. After all, there’s little or no forage available, so they use their honey and pollen stores.

The fat-bodied overwintering bees that are reared in autumn have a very different physiology to the ephemeral summer workers. The latter have a life-expectancy of 5-6 weeks whereas overwintering bees can live for many months 2.

But they’re not immortal.

Throughout the winter there’s a slow and steady attrition of these workers. As they die off the clustered colony gradually reduces in volume, shrinking from the size of a medicine ball, to a football, to a grapefruit … you get the picture.

Some brood rearing does occur. The queen often stops laying after the summer nectar flows stop 3 and laying might be sporadic through the autumn, dependent upon weather and forage availability.

Late summer brood frame from a nuc ...

Late summer brood frame from a nuc …

However, by the turn of the year she starts laying again. At a much reduced level to her maximum rate, but laying nevertheless and, with sufficient workers in the colony and as forage become available, this rate will increase.

The amount of brood reared during the winter period (late autumn to early spring) isn’t enough to make up for the losses that occur through attrition. This explains why colonies are much smaller in the spring than the early autumn.

Strong, healthy, well-provisioned and weathertight

Knowing what’s happening in the colony during the winter makes the requirements that must be met understandable.

  • Strong colonies start the winter with ample bees. Assuming the same attrition rate, a larger colony will get through the winter stronger than a smaller one. There will be more workers available to ‘reach’ stores (I’ll deal with this in the next week or two) and keep the queen and brood warm. Hence there will be more foragers to exploit the early crocus, snowdrop and willow.
  • Healthy colonies will have a lower attrition rate. The overwintering workers will live longer. High levels of deformed wing virus (DWV) are known to shorten the life of winter bees. To minimise the levels of DWV you must reduce the levels of Varroa in the colony. Critically, you must protect the overwintering bees from Varroa exposure. Treat too late in the season and they will already be heavily infected …
  • Well-provisioned colonies have more than enough stores to survive the winter. The clustered colony will have to move relatively short distances to access the stores. As a beekeeper, you won’t have to constantly meddle with the colony, lifting the lid and crownboard to add additional stores in midwinter.
  • Weathertight colonies will be protected from draughts and damp 4.The hive must be weathertight and, preferably, not situated in a frost pocket or damp location 5.

Winter preparation

Once the honey supers are off all activities in the apiary are focused on ensuring that these four requirements for successful overwintering are achieved in a timely manner.

Clearing bees from wet supers ...

Clearing bees from wet supers …

Weak colonies are united with strong colonies. At this stage in the season – other than disease – the main reason a colony is likely to be weak is because the queen isn’t up to the job. If she’s not now, what chance has the colony got over the winter or early spring? 6

Varroa treatment is started as early as reasonably possible with the intention of protecting the overwintering bees from the ravages of DWV. This means now, not early October. Use an appropriate treatment and use it correctly. Apiguard, oxalic acid (Api-Bioxal), Apivar etc. … all have been discussed extensively here previously. All are equivalently effective if used correctly.

All colonies get at least one block (12.5kg) of bakers fondant, opened like a book and slapped (gently!) on the tops of the frames. An eke or an empty super provides the ‘headspace’ for the fondant block. All of the Varroa treatments listed above are compatible with this type of feeding simultaneously 7.

Hopefully, hives are already weathertight and secure. Other than strapping them to the hive stands to survive winter gales there’s little to do.

They think it’s all over!?

It is … almost 🙂


Colophon

They think it’s all over! is a quote by Kenneth Wolstenholme made in the closing stages of the 1966 World Cup final. Some fans had spilled onto the pitch just before Geoff Hurst scored the the last goal of the match (England beat West Germany 4-2 after extra time), which Wolstenholme announced with “It is now, it’s four!”. This was the only World Cup final England have reached, whereas Germany have won four.

As Gary Lineker says “Football is a simple game; 22 men chase a ball for 90 minutes and at the end, the Germans win.”

Robbery

Robber

Robber

Another apiculture-flavoured tale of daylight robbery, literally, to follow the post on hive and bee thefts last week.

However, this time it’s not dodgy bee-suited perps with badly inked prison tats offering cheap nucs down the Dog and Duck.

Like other offenders, the robbers this week wear striped apparel, but this time it’s dark brown and tan, or brown and yellow or black and yellow.

I am of course referring to honey bees and wasps (Vespa vulgaris and V. germanica), both of which can cause major problems at this time of year by robbing weak colonies.

Carb loading

The season here – other than for those who have taken colonies to the heather – is drawing to a close. The main nectar sources have more or less dried up in the last fortnight. There’s a bit of rosebay willow herb and bramble in the hedgerows and some himalayan balsam in the river valleys, but that’s about it.

Colonies are strong, or should be. With the dearth of nectar in the fields, the foragers turn their attention to other colonies as a potential source of carbohydrates. Colonies need large amounts of stores to get through the winter and evolution has selected a behavioural strategy – robbing of weaker colonies – to get as much carbohydrate from the easiest possible sources.

Like the nucs you carefully prepared for overwintering 🙁

At the same time, wasps are also wanting to pile in the carbs before winter 1. In the last fortnight the wasp numbers in my apiaries and equipment stores have increased significantly.

Jekyll and Hyde

Within a few days in late summer/early autumn the mood and attitude of colonies in the apiary changes completely.

During a strong nectar flow the bees single-mindedly pile in the stores. They alight, tail-heavy, on the landing board, enter the hive, unload and set out again. There’s a glut and they ignore almost anything other than bingeing on it. Inspections are easy. Most bees are out foraging and they are – or should be – well-tempered and forgiving. 

Laden foragers returning ...

Laden foragers returning …

But then the nectar flow, almost overnight, stops.

Colonies become markedly more defensive. They are packed with bees and they’re tetchy. There’s nothing to distract them, they resent the intrusion and they want to protect their hard-won stores 2.

At the same time, they quickly become more inquisitive, investigating any potential new source of sugar. If you shake the bees off a frame and leave it standing against the leg of the hive stand there will be dozens of foragers – many from nearby colonies – gorging themselves on the nectar.

If you spill unripened nectar from a frame they’re all over it, quickly forming a frenzied mass – probably from several different hives – scrabbling to ‘fill their boots’.

They also closely investigate anything that smells of nectar or honey. Stacks of equipment, empty supers, hive tools, the smoker bellows … anything.

Robbing

And it’s this behaviour that can quickly turn into robbing.

The foragers investigate a small, dark entrance that smells of honey … like a nuc in the corner of the apiary. They enter unchallenged or after a little argy-bargy 3, find the stores, stuff themselves, go back to their colony and then return mob-handed.

Before long, the nuc entrance had a writhing mass of bees trying to get in, any guards present are soon overwhelmed and, in just a few hours, it’s robbed out and probably doomed.

This is the most obvious – and rather distressing – form of robbing. Wasps can do almost exactly the same thing, with similarly devastating consequences.

Prevention is better than cure

Once started (and obvious), robbing is difficult to stop. About the only option is to seal the target hive and remove it to another apiary a good distance away.

Far better to prevent it happening in the first place.

The best way of preventing robbing is to maintain large, strong and healthy colonies. With ample bees there are ample guards and the colony will be able to defend itself from both bees and wasps. Strong colonies are much more likely to be the robbers than the robbed.

For smaller colonies in a full-sized hive, or nucleus colonies or – and these are the most difficult of all to defend – mini-nucs used for queen mating, it’s imperative to make the hive easy to defend and minimise attracting robbers to the apiary in the first place.

The underfloor entrances on kewl floors are much easier to defend than a standard entrance and small entrances are easier to defend than large ones. ‘Small’ might mean as little as one bee-width … i.e. only traversable by a single bee at a time.

Smaller is better ...

Smaller is better …

You can even combine the two; insert a 9mm thick piece of stripwood into the Kewl floor entrance to reduce the space to be defended to a centimetre or two. If – as happened tonight when returning wet supers to the hives – I don’t have a suitable piece of stripwood in the apiary I use a strip of gaffer tape to reduce the entrance 4.

Gaffer tape is also essential to maintain the integrity of the hive if some of the supers are a bit warped. Wasps can squeeze through smaller holes than bees and the quick application of a half metre along the junction between boxes can save the day 5.

The poly nucs I favour have a ridiculously large entrance which I reduce by 90% using foam blocks, dried grass, gaffer tape, wire mesh or Correx.

Correx, the beekeepers friend ...

Correx, the beekeepers friend …

Don’t tempt them

Finally, reduce the inducement robbers – whether bees or wasps – have to investigate everything in the apiary by not leaving open sources of nectar, not spilling honey or syrup, clearing up brace comb and ensuring any stored equipment is ‘bee proof’.

You don’t need to inspect as frequently at this time of the season. The queen will have reduced her laying rate and colonies are no longer expanding. With no nectar coming in they should have sufficient space in the brood nest. There’s little chance they will swarm.

If you don’t need to inspect, then don’t. The ability to judge this comes with experience.

If you do have to inspect (to find, mark and clip a late-season mated queen for example 6 do not leave the colony open for longer than necessary. Any supers that are temporarily removed should be secured so bees and wasps cannot access them.

Wet supers

If you’re returning wet supers after extraction, do it with the minimum disruption late in the evening. These supers absolutely reek of honey and attract robbers from far and wide. Keep the supers covered – top and bottom – gently lift the crownboard, give them a tiny puff of smoke, place the supers on top, replace the roof and leave them be.

Returning wet supers

Returning wet supers …

In my experience wet supers are the most likely thing to trigger a robbing frenzy. I usually reduce the entrance at the same time I put the wet supers back and try to add wet supers to all the colonies in the apiary on the same evening 7.

I generally don’t inspect colonies until the supers are cleaned out and ready for storage.


 

Thieving b(ee)’stards

HMP Bee Shed

HMP Bee Shed

There’s something both vaguely amusing and deeply repellent about hive and bee thefts.

Vaguely amusing in terms of the way the press cover it and possibly in the way it’s perceived by the general public. The latter have visions of beesuited ‘rustlers’ rounding up ‘herds’ of bees and making off with them in the dead of night. The press do little to alter this perception, generally stressing the large number of individual bees stolen in articles littered with beekeeping gaffes.

The deeply repellent aspect of honey bee thefts is that most must be carried out by beekeepers.

Handling bees in large numbers is a daunting prospect for most of the general public. Even the most light-fingered ne’er-do-well is likely to think twice about making off with a 40 litre box packed with stinging insects.

It requires specialist knowledge and equipment … or, in their absence, tener cojones as the Spanish say.

Bee and hive theft is not like a ned1 stealing a smartphone and flogging it at a car boot sale … it’s more like a surgeon being involved in organ trafficking.

Whether to make up for their own beekeeping inadequacies or simply to make a quick profit, this type of ‘inside job’ is an unsavoury reminder that some – hopefully a very few – ‘beekeepers’ have criminal tendencies and cannot be trusted.

Prepare to be amused

“Rustler steals 40,000 bees in Britain’s biggest hive heist in years” is a recent headline in The Guardian. The article describes the theft of a single hive (presumably gold-plated as it’s valued at £400, though perhaps this price reflects the fact that it’s the ‘biggest’ hive) from a ‘ditch’ in Anglesey, blaming the recent increase in bee thefts on the spiralling cost of ‘nukes’ (sic).

The Daily Mail announces that bee hives are stolen and sold for up to £8,000 a time, and helpfully illustrate the article with a picture of a bumble bee (almost certainly a male) and the caption “Some queen bees are worth £180 …”.

Actually ... some breeder queens cost €450

Actually … some breeder queens cost €450

I can’t help but think that the emphasis on the ‘value’ encourages some of the thefts. After all, what else valued at £400 (or £8000 for that matter) do you know about that’s left unattended and unlocked for days at a time in a remote corner of a farmer’s field.

As an aside, The Daily Mail obviously don’t realise that some breeder queens sell for a lot more than £180 …  😯

Scaling up

It’s not really clear from the Daily Mail article (above) whether it was one or many hives that were stolen. However, since many apiaries will contain multiple hives, it’s not unusual to have the entire lot vanish.

Another poorly punned headline from The Telegraph announces “Britain’s biggest bee sting: One million insects stolen from Oxfordshire hives”, choosing to emphasise the total number of insects, rather than the 40 hives that went missing.

Pedantically, the hives and  the bees were stolen … they didn’t just take the bees, though that happens as well as will soon become clear.

But, as with so many other things, you need to go across the Atlantic to experience the biggest bee and hive thefts. The scale of commercial beekeeping operations in the USA means that there’s added incentive and opportunity. Two ‘beekeepers’ were charged in 2017 with the theft of 2,500 hives (no need to count the bees this time, hive numbers alone were sufficiently impressive) worth almost $1M.

Hives were stolen from apiaries at night, spirited away on a flatbed trailer and moved to an isolated location where they were repainted. “It looked like a chop shop for bee hives,” Fresno detectives said.

Not hiding hives

The Oxfordshire bee heist was of overwintering hives in a field that “couldn’t be seen from the road”. As I’ve previously discussed, obscurity does not guarantee security.

High resolution satellite imagery is increasingly available and it’s easy to find apiaries. While preparing this post I looked at Google and Bing maps of an apiary I know well. It is effectively invisible from public roads or the adjacent football pitch.

The satellite images are taken at different times 2, so aren’t identical. The first two images are at about the same scale. The three white rectangles in the Bing maps image are poly tunnels, each about 5-6 metres long. The regularly-spaced hives are pretty obvious.

The image on the right is the current enhanced Google maps view, in this individual hives can clearly be counted. You can even discriminate between paving slabs with hives on stands and those that are unoccupied.

A beekeeper thief could spend a few winter evening scanning these sorts of satellite images and easily identify likely apiaries, whether they can be seen from the road or not.

Security

I’m going to write more extensively in the future about deterring thieves as there’s a more important topic to cover here.

You can place hidden cameras near the apiary (to catch a thief … or obvious ones to deter). There are now ways of installing GPS-trackers in hives. These trigger a remote alarm if moved. You can ‘label’ equipment and make it uniquely traceable using SmartWater-like solutions.

Alternatively you can consider physical deterrents, like simply screwing the hive floor to the stand (from inside the hive). It’s unlikely the thief will have spare floors. I’ve heard of people plugging a hole through the hive floor with a bung, the latter firmly attached to the hive stand. The thief places the hive in the back of the estate car and … you can imagine the rest 🙂

Apiary gate

Apiary gate

Or just use an enormous fence and a big padlock.

Gamekeeper turned poacher

For reasons outlined in the opening paragraph I suspect the majority of these thefts are by beekeepers or – as Martin Smith of the BBKA puts it – “beekeepers or at least those with a rudimentary knowledge of the craft”.3

A recent theft announced on the Sottish Beekeepers Association interactive forum (SBAi) clearly emphasises the involvement of beekeepers. Here are the relevant bits of the post:

… Came across a set of plainly disturbed hives near Dundee today whilst doing heather prep[arations]. These were double deep hives with brood in 12 to 15 bars, plenty food and pollen, but were being robbed. Almost no bees, no queen, no q.cells, brood in all stages inc eggs, combs not back in correct order …

Large hives, full of brood but empty of bees. Odd. The poster (a hugely experienced commercial beekeeper) concludes:

Shook swarms plainly been removed from them.

Conducting shook swarms on large double brood colonies is unlikely to be the work of someone with just a rudimentary knowledge of the art. Done properly, it involves first finding and caging the queen, then shaking all the bees off all the frames. It’s hard work and to someone unused to working with lots of bees it would be a daunting undertaking.

Pssst … wanna buy a nuc?

The SBAi post author suggests that the likely fate for those bees is to be split into nucs and sold on to unsuspecting beekeepers. It’s really a bit late in the season … remember that you should ideally only buy nucs with at least 2-3 frames of brood in all stages from the queen in the box 4.

However, beginners desperate for bees who don’t purchase from a known and trusted source are unlikely to be worrying about the quality of the bees they buy.

I never knew there was so much in it …

But those beginners purchasing nucs are possibly getting more than they bargained for, as is clear from the rest of the post on the SBAi:

The bad news for the thief is that this apiary has had EFB [European foulbrood] earlier in the summer and is still under a standstill order, and one of the hives shaken was the one next to the (removed and destroyed earlier) EFB case. This must be considered a super high risk bit of theft ………… so if you are offered bees by an unknown source in the area be very very careful.

It’s not really bad news for the thief … but it is for the purchaser, or potentially for anyone in the area (or outside the area) who keeps bees and may now get a potentially EFB-infected colony5 in the garden next door 🙁

Ironically, great advances have been made recently in molecular fingerprinting of foulbroods to determine transmission pathways. This is similar to the DNA fingerprinting that can unambiguously link a person to the scene of a crime. It should soon be possible to definitively demonstrate the EFB in that dodgy nuc you bought from the bloke in The Crooks Arms public house was from bees stolen from an apiary ‘near Dundee’.

Nuc behind bars

Nuc behind bars

Caveat emptor

That’s a doubly sour note to end on. One or more beekeepers must have been involved and it could result in the further spread of EFB.

It’s been a great summer for bees. Many experienced beekeepers will likely have an excess of bees at this time of the season. The usual high demand for nucs in early Spring has probably all been met. However, there will still be people wanting to start beekeeping.

It is this group of novices that might end up buying a poorly balanced nuc of stolen bees with a side order of EFB.

What Not a bargain.

If you do want to buy bees6 then:

  • Buy local bees.
  • Buy from a known or trusted source. Ask around. The beekeeping community is pretty small. Most beekeepers and beekeeping associations are very approachable.
  • Inspect the nuc before purchase. If there’s little or no brood, frames with undrawn foundation or an obvious mix of bees then do not buy it.

Finally, if you don’t know whether the bees are local, whether the source is trusted or whether the nuc is high quality … stop.

Get some training, get a mentor and get some help with the purchase.


Colophon

The title of this post is an obvious bee-flavoured concatenation of a well known insult that strikes hard at one’s personal integrity and social standing, both, in an economy of words”.

The simpler concatenation to B’Stard was used by the late Rik Mayall as the surname of his character (Sir Alan Beresford B’Stard) in The New Statesman, a late-80’s sitcom satirising the then Conservative Party government. B’Stard would stop at nothing to fulfil his megalomaniac ambition. He was “selfish, greedy, dishonest, devious, lecherous, sadistic, self-serving”. 

It strikes me that most of these terms could also be applied to bee rustlers.

In perpetuity

Yet more frames ...

Yet more frames …

As I write this we’re approaching midsummer of one of the best years beekeeping I’ve had in a decade. In Fife we’ve had excellent weather, and consequently excellent nectar flows, for weeks. Queen mating has been very dependable. I’ve run out of supers twice and have been building frames like a man possessed.

I’m not complaining 😉 1

In a few short weeks it will be all over. The season won’t have ended, but this non-stop cycle of inspections, adding supers, building frames, splitting colonies, making up nucs, taking off laden supers, extracting and more inspections will be largely finished.

We’re in clover

Busy bees ...

Busy bees …

Literally, as it’s been yielding really well recently.

I’ve written previously about The Goldilocks principlenot too much, not too little – and bees. As an individuals’ competence improves over successive seasons, colony numbers can quickly change from too few to too many.

A single production 2 colony in a good year should probably also be able to generate a nuc for overwintering and possibly a new queen for re-queening without significantly compromising honey production.

That’s certainly been the case this year. I’ve got a few colonies that produced nucs in May, were requeened (through vertical splits) in late June or early July and that have produced several supers of honey, either from spring or summer flows.

Or in a few cases, from both. And it’s not quite over yet 🙂

But, there’s always a but …

I said in the opening paragraph it’s an exceptional year. The ability to produce a surfeit of both bees and honey requires some skill, some luck and some good timing.

In a bad year, just getting one of the three – a new nuc, a new queen or a honey surplus – from a colony should be regarded as a major success.

How do you cope with problems encountered in these bad years?

Self-sufficiency

I’m a strong supporter of self-sufficiency in beekeeping. Although I’m not fundamentally opposed to purchasing queens or nucs, I do have concerns about importation of new virus strains and other ‘exotics’ that do or will threaten our beekeeping. However, buying in high quality bees for stock improvement is understandable, expensive at times and the foundation of at least some commercial (and amateur, but commercially viable) beekeeping.

I See You Baby

I See You Baby

What I’m far less keen on is purchasing bees – a significant proportion of which are imported – to compensate for lazy, slapdash or negligent beekeeping.

And there’s too much of that about … anyone who has been keeping bees successfully will have heard these types of comments:

  • Surely I can get away with less frequent inspections? I always have six weeks sailing in May and June … but I do want to make my own honey and mead
  • They all died from starvation sometime last year but I’ll buy some more in March from that online supplier of cheap bees (Bob’s Craptastic Nucs … Bees for the Truly Impatient)
  • Varroa treatment? Nope, not in the last couple of years mate. I’ve never seen one of them Verona, er, Verruca thingies so I don’t think my bees are infected with them anyway
  • I knocked off all the queen cells to stop them swarming in June and July. They just might be queenless. I know it’s early October but do you have a mated queen spare?

I’ve heard variants of all the above in the last few months.

In perpetuity

This stop-start beekeeping is not really beekeeping. I’ve discussed this in Principles and Practice extensively. I’ve called them beehadders before but perhaps the term ‘serial ex-beekeeper’ might be more accurate.

The reality is that, with a little skill, a little luck and just reasonable timing you can have bees in perpetuity … the real topic of this post.

In perpetuity meaning you are self-sufficient for stock and for spares.

You’re able to exploit the good years and survive the bad. You only need to buy in bees for stock improvement or to increase genetic diversity (which may be the same thing).

Once you’ve got bees, you’ve always got bees.

It’s a good position to be in. It gives you security to survive accidents, self-inflicted snafu’s and even the odd fubar 3. You are no longer dependent upon the importer, the supplier or your mate in the local association to bail you out. It gives you confidence to try new things. It means you can cope with vagaries in the weather, forage availability or simple bad luck.

How is this nirvana-like state of beekeeping self-sufficiency achieved?

I think it can be distilled to just two things – one is easy, the other slightly more challenging.

Firstly, you need to maintain a minimum of two hives. Secondly, you need to develop an appreciation of how the colony develops and understand when interventions and manipulations are most likely to be successful.

One is not enough

I’ve discussed the importance of a second hive previously. With one hive, beekeeping errors (or just plain bad luck) that result in a queenless, broodless and eggless colony might well be a catastrophe.

With two hives, you can simply take a frame of eggs from the second colony and voila, they’ll raise a new queen and your imminent categorisation as an ex-beekeeper is postponed.

Two are better than one …

The benefits of two colonies far outweigh the expense of the additional equipment and time taken to manage them. In a good year you’ll get twice as much honey to impress your friends and neighbours at Christmas, or to sell in the village fete. In a bad year, the ability to unite a weak colony headed by a failing queen in late September, might mean the difference between being a beekeeper and being an ex-beekeeper the following Spring.

Maintaining two colonies in the same apiary significantly increases your chances of having bees in perpetuity.

The art of the probable 4

Beekeeping isn’t really very difficult. You provide the colony with somewhere to live. You give them sufficient extra space to dissuade them from swarming (swarm prevention), or intervene in a timely manner to stop them swarming (swarm control). If you harvest some or all of the honey you provide them with more than they need of an alternative source of sugar(s) at the right time. Finally, you monitor and control the pathogens that afflict them and apply appropriate treatments, at the right time, to minimise their impact.

As you can see, timing is important. Do things at the right time and they work … at the wrong time they don’t.

Timing is also important in terms of the frequency of inspections (which I’ve briefly discussed before, so won’t repeat here), and in the manipulations of the colony.

These colony manipulations include – but aren’t restricted to – providing them space to expand, spreading the brood nest, making nucs, rearing queens or at least getting queens mated, adding supers, uniting weak colonies and feeding them up for the winter.

Again, if you do the manipulations at the right time they will probably work. Hence the ‘art of the probable’.

The time is right

For many of these manipulations, the ‘right time’ essentially depends upon the development of the colony and weather. And, of course, colony development is itself very much influenced by the weather.

Consider queen mating. Of the various manipulations listed above, this is one upon which the future viability of the colony is absolutely dependent.

Queen mating usually occurs mid-afternoon during dry, preferably sunny weather, on days with relatively light winds and temperatures of at least 18°C. Therefore if there’s a mature virgin queen in your hive 5, the weather is suitable and there are drones flying, she’ll probably get mated.

Good laying pattern ...

Good laying pattern …

Days like this occur pretty dependably in late May and June. It’s no coincidence that this is the peak swarming season.

Conversely, if through carelessness or neglect your colony goes queenless in late September, the probability of getting a warm, dry, calm afternoon are much less. It’s therefore less probable (and potentially highly improbable) that the new queen will get mated.

That’s not to say it won’t happen … it might, but it is less probable 6.

Beekeeping nirvana

In re-reading this post I feel as though I’ve skirted around the core of the issue, without satisfactorily tackling it.

Having bees in perpetuity is readily achievable if you have a backup hive and you understand how colony development and the weather determines what you can and cannot do to the colony during the season 7.

Having two hives but inadvertently damaging both queens in March during heavy-handed inspections will not provide bees in perpetuity.

Conversely, irrespective of your best efforts, a single terminally broodless and queenless colony at the peak of the swarming season cannot magically create a new queen … meaning you’re about to become an ex-beekeeper.

Another one for the extractor ...

Another one for the extractor …

I’ve used queen mating as an example because it’s a binary event … she’s mated successfully or she’s not, and colony survival absolutely depends upon it.

However, the timing of many of the other manipulations can also influence the strength, health and robustness of the colony. Providing too much space in cold weather delays expansion as there are too few bees to keep the brood warm. Trying to feed syrup very late in the season may mean it’s too cold for them to access the feeder, leading to starvation. Finally, using the wrong miticide at the wrong time is a guaranteed way to ensure more mites survive to damage the colony in the future.

Learn to do the right thing at the right time … to both your colonies. The recipe to having bees in perpetuity.


Colophon

In (for or to) perpetuity means “for all time, for ever; for an unlimited or indefinitely long period” and  has origins in Latin and French with English usage dating back to the early 15th Century.

‘Unlimited or indefinitely long’ could also refer to the length of this post or the delay to my flight last Sunday. You can thank EasyJet for providing me with more than ample time to write this magnum opus.

Or write and complain for the very same reason 😉

Sphere of influence

How far do honey bees fly? An easy enough question, but one that is not straightforward to answer.

The flight range of the honeybee ...

The flight range of the honeybee …

Does the question mean any honey bee i.e. workers, drones or the queen? As individuals, or as a swarm?

Is the question how far can they fly? Or how far do they usually fly?

Why does any of this matter anyway?

Ladies first …

Workers

The first definitive experiments were done by John Eckert in the 1930’s. He located apiaries in the Wyoming badlands at increasing distances from natural or artificial forage 1. Essentially the bees were forced to fly over a moonscape of rocks, sand, sagebrush and cacti to reach an irrigated area with good forage. He then recorded weight gain or loss of the hives located at various distances from the forage.

Wyoming badlands

Wyoming badlands …

The original paper can be found online here (PDF). The experiments are thorough, explained well and make entertaining reading. They involved multiple colonies and were conducted in three successive years.

Surprisingly, Eckert showed that bees would forage up to 8.5 miles from the colony. This means they’d be making a round trip of at least 17 miles – and probably significantly more – to collect pollen and nectar.

However, although colonies situated within 2 miles of the nectar source gained weight, those situated more than 5 miles away lost weight during the experiments.

Gain or loss in hive weight ...

Gain or loss in hive weight …

Therefore, bees can forage over surprisingly long distances, but in doing so they use more resources than they gain.

John Eckert was the co-author (with Harry Laidlaw) of one of the classic books on queen rearing 2. His studies were probably the first thorough analysis of the abilities of worker bees to forage over long distances. Much more recently, Beekman and Ratnieks interpreted the waggle dance (PDF) of bees to calculate foraging distances to heather. In these studies, only 10% of the bees foraged ~6 miles from the hive, although over 50% travelled over 3.5 miles.

Queens

Queens don’t get to do a lot of flying. They go on one or two matings flights, perhaps preceded by shorter orientation flights, and they might swarm.

Heading for a DCA near you ...

Heading for a DCA near you …

I’ll deal with swarms separately. I’ll also assume that the orientation flights are no greater than those of workers (I don’t think there’s any data on queen orientation flight distance or duration) at no more than ~300 metres 3.

On mating flights the queen flies to a drone congregation area (DCA), mates with multiple drones and returns to the colony. DCA’s justify a complete post of their own, but are geographically-defined features, often used year after year.

There are a number of studies on queen mating range using genetically-distinguishable virgin queens and drones in isolated or semi-isolated locations. They ‘do what they say on the tin’, drone congregate there and wait for a virgin queen

In the 1930’s Klatt conducted studies using colonies on an isolated peninsula and observed successful mating at distances up to 6.3 miles

Studies in the 1950’s by Peer demonstrated that matings could occur between queens and drones originally separated by 10.1 miles 4. These studies showed an inverse relationship between distance and successful mating.

More recently, Jensen et al., produced data that was in agreement with this, with drone and queen colonies separated by 9.3 miles still successfully mating 5.

However, this more recent study also demonstrated that more than 50% of matings occurred within 1.5 miles and 90% occurring within 4.6 miles.

Just because they can, doesn’t mean they do 🙂

Drones … it takes 17 to tango …

Seventeen of course, because that’s one queen and an average of 16 drones 😉

There’s a problem with the queen mating flight distances listed above. Did the queen fly 9 miles and the drone fly just a short distance to the DCA?

Or vice versa?

10 miles ... you must be joking!

10 miles … you must be joking!

Or do they meet in the middle?

Do queens choose 6 to fly shorter distances because it minimises the risk of predation and because they are less muscle-bound and presumably less strong flyers than drones?

Alternatively, perhaps drones have evolved to visit local DCAs to maximise the time they have aloft without exhausting themselves flying miles first?

Or getting eaten.

It turns out that – at least in these long-distance liaisons – it’s the queen that probably flies further. Drones do prefer local DCAs 7 and most DCAs are located less than 3 miles from the ‘drone’ apiary 8.

Swarms

I’ve discussed the relocation of swarms recently. Perhaps surprisingly (at least in terms of forage competition), swarms prefer to relocate relatively near the originating hive. Metres rather than miles.

The sphere of influence

Effective foraging – in terms of honey production (or, for that matter, brood rearing) – occurs within 2-3 miles of the hive. This distance is also the furthest that drones usually fly to occupy DCAs for mating.

Queens can fly further, but it’s the law of diminishing returns. Literally. The vast majority of matings occur within 5 miles of the hive.

In fact, other than under exceptional circumstances, a radius of 5 miles from a colony probably represents its ‘sphere of influence’ … either things that can influence the colony, or that the colony can influence.

Why does this matter?

Worker flight distances are relevant if you want to know the nectar sources your bees are able to exploit, or the pollination services they can provide. In both cases, closer is better. It used to also be relevant in trying to track down the source of pesticide kills, though fortunately these are very much rarer these days.

Closer is better ...

Closer is better …

Workers not only fly to forage on plants and trees. They also fly to rob other colonies. I don’t think there are any studies on the distances over which robbing can occur, but I’ve followed bees the best part of a mile across fields from my apiary to find the source of the robbing 9.

All of these movements can also transport diseases about, either in the form of phoretic Varroa mites piggybacking and carrying a toxic viral payload, or as spores from the foulbroods.

Drone and queen flight distances are important if you’re interested in establishing isolated mating sites to maintain particular strains of bees. My friends in the Scottish Native Honey Bee Society have recently described their efforts to establish an isolated queen mating site in the Ochil Hills.

And I’m interested as I now have access to a site over 6 miles from the nearest honey bees in an area largely free of Varroa.

It’s not the Wyoming badlands, but it’s very remote 🙂


 

Anticipation

Finally, the winter appears to be receding and there’s pretty good evidence that the beekeeping season will shortly be starting. The early season pollen sources for the bees – snowdrops and crocus – are almost completely finished, but the willow is looking pretty good and the gorse is flowering well.

Actually, gorse flowers quite well year-round, but it’s only now warm enough for the bees to access it.

Difurzeion

From an evolutionary point of view I’ve wondered why gorse ‘bothers’ to flower in mid-winter when there must be almost no pollinating insects about. Of course, as Dobzhansky said in the 1970’s “Nothing in Biology Makes Sense Except in the Light of Evolution” … gorse flowers all year because there must be a selective advantage for it to do so.

Late December gorse ...

Late December gorse …

It turns out that it’s a little more complicated than me just being unable to observe winter-flying pollinating insects. Gorse probably flowers in midwinter for a couple of reasons.

Firstly, there are winter-flying pollinators, at least on warmer days. Secondly, the flowers are a cunning design 1 that allows self-pollination, even when tightly closed on a cold, midwinter day when covered in snow. This probably explains the clonal expansion and invasiveness of the plant. Finally 2 weevils of the Exapion genus eat the seeds … by flowering, and subsequently setting seed in midwinter, the gorse can avoid the attention of the weevils, which need warmer weather 3.

Winter-flowering in gorse is genetically-determined. A winter-flowering plant probably gives rise to progeny plants that also flower in winter.

An apology

That was all a bit off-topic. However, it does explain the shocking pun used to head the previous section. Furze is another name for gorse, Ulex europaeus.

Now back to the bees …

Moving to higher ground ...

Moving to higher ground …

Inevitably we’ve had some April showers and the final bee moves over the last fortnight involved dodging the rain and wading through some minor flooding. Almost everything is now where it should be and – although perhaps a little later than usual – I can make some of the last-minute preparations for the season ahead.

Frames and supers

The beekeeping season in Scotland – or at least my beekeeping season – involves long periods of near-total inactivity interrupted by May and June, which are usually totally manic. This ~9 week period covers the major swarming season and the best time of the year to rear queens. Both can happen at other – generally later – times of the year, but the weather becomes a major influence on their success. The last two seasons have been characterised by rubbish weather in July and August, resulting in poorly mated late season queens.

A consequence of the expected frenetic activity in May and June is that there’s no time to leisurely make up a few frames, or assemble a few supers. If they’re not ready now, they probably won’t ever be.

I’ve therefore already built a couple of hundred frames and just have to fit the foundation into some of them. Many of the frames I use are foundationless, but a proportion still have foundation. The latter are useful to intersperse with foundationless to encourage the bees to draw parallel comb.

Supers and frames with drawn comb are all safely stacked up from last season. Sometime over the next fortnight I’ll finish checking the last of these boxes over. Do they have a full set of frames? Are all the frames drawn? It’s irritating grabbing a box or two in the middle of a good nectar flow to find they only contain three frames, or it’s unwired thin foundation and unsuitable for the OSR.

The other thing I do is tidy up wavy or bulging sections of drawn comb. These are the frames that the bees have drawn out, maintaining bee space with the adjacent frame, but that leave gaping holes when put next to a different drawn comb 4. Life is too short to try and pair up the frames correctly 5. Instead I just use a sharp breadknife to make the comb reasonably parallel with the frame top bar. The bees tidy it up quickly and it certainly makes mixing and matching frames from different supers much easier.

Fermenting honey

The other frame-related task is to go through the stacked up boxes of brood frames saved from last year. These, and the drawn super frames, are some of the most valuable resources a beekeeper has. Assuming the frames are in good condition and there haven’t been too many rounds of brood reared in the frames they are invaluable when making up nucs during the season.

Some of these brood frames will have inevitably contained nectar or uncapped honey at the end of the previous season. Over the winter this tends to ferment and make a bit of a mess. The nectar drips out unless the frames are held vertically. It can look bubbly or frothy and it pongs a bit (usually, and unsurprisingly, of yeast).

Washing frames ...

Washing frames …

I don’t like using these without cleaning them up a bit first. The bees usually clean up small amounts of fermented honey, but often ignore frames packed with the stuff. I shake out the fermented honey and soak the frames in a tub of water for a few minutes. I then shake out the water and leave them to air dry before storing them for the season ahead.

This is the sort of job that needs to be done on a cool, dry day. If it’s warm you’ll likely be plagued with bees investigating the smell.

Drying brood frames ...

Drying brood frames …

Brood frames just containing capped honey can be used ‘as is’. The bees don’t cap it until the water content is low enough to stop fermentation.

In contrast, the really old, black frames are either discarded outright or used for making up bait hives. There’s no point in trying to extract wax from them as there’s almost none left.

Be(e) prepared

Finally, the bee bag gets a spring clean. I empty everything out and chuck away all the rubbish that seems to accumulate during the season … the squeezed-together bits of brace comb, the torn nitrile gloves, the sheets of newspaper for uniting etc. Everything goes back together in labelled ice-cream cartons (‘daily’, ‘queen rearing’), having checked they contain the essentials – sharp scissors, Posca marking pens and a queen marking cage, additional cages for queen introduction, grafting glasses and a sable paintbrush etc.

I re-stock the honey bucket full of smoker fuel. This contains a mix of wood chip animal bedding, the lids of egg boxes not used to make firelighters and some lovely dried rotten wood. The smoker also gets its annual de-coke. Over the season you can get quite a build up of tarry, sooty deposits in the smoker, particularly on the inside of the lid. Using a blowtorch and a little encouragement from the pointed end of a hive tool it’s easy enough to clean all these out. As a result, the smoker will stay lit longer and generally work better.

Smoker de-coke ...

Smoker de-coke …

OK … bring it on 🙂


Colophon

This post was supposed to have been last week. However, a delayed flight meant I was stranded on the tarmac in ‘airplane’ mode when I should have been changing the scheduled posting date. D’oh! Instead Let there be light, which I’d written a couple of weeks ago and was already scheduled as a backup, snuck out. By the time it appears – the 20th of April – I expect to have conducted the first full set of inspections and I’ll be playing catch-up with the next couple of posts as the season kicks off.

Fife weather mid-April 2018

Fife weather mid-April 2018

Stop press … with great weather over the latter part of the week I’ve got round my apiaries and inspected all colonies. With the exception of the two known duds, all are queenright and building up to varying extents … from OK to very well. The strongest will need supering this weekend. Considering how long and cold the winter has been – average temperatures November to March have been 3-4°C – this was encouraging and 3 weeks earlier than I got into some colonies in 2017.

It was great to be beekeeping again 🙂

Old and new duds

The Beast from the East ...

The Beast from the East …

Despite the best efforts of the Beast from the East 1 Spring is definitely on the way.

The snowdrops and crocus have been out for some time, willow is looking good, large queen bumble bees are searching for nest sites and the temperature here in Fife has consistently reached double figures during the warmest part of the day for the last week.

Consistently … but only just and only briefly.

Pollen boost

Pollen boost …

Consequently it’s too cold for full inspections and the only colonies I’ve been ‘in’ are the two described below. However, I’ve not ignored the others. I’ve lifted the crownboard on most colonies to determine their approximate strength (or just peeked through those with perspex crownboards which is even less intrusive) and have continued to heft colonies to see if they have enough stores. Those that were feeling a bit light have had a fondant top up. I’ve also given several colonies a pollen boost to help them rear early season brood.

Other than that – and moving colonies to the new bee shed – I’ve left them well alone.

Early season checkups

On the warmest part of the warmest day of the week I visited the apiary to check the colony strength. With the exception of two, all were flying well with foragers returning laden with pale yellow pollen.

However, two were suspiciously quiet, with only a handful of bees going in and out 2.

A pretty small handful.

Almost none of the bees returning to these two colonies carried pollen.

One was a five frame poly nuc in the bee shed. This had been made up in mid/late summer while the parental colony was requeened. The old queen, a frame of emerging brood with the adhering bees and a frame of stores had gone into the nuc box. The little colony had built up reasonably well going by my infrequent peeks through the transparent crownboard, but not well enough to move them to a full hive for the winter.

The other suspiciously quiet colony was a full (or full-sized 🙁 ) hive headed by one of the older queens in my apiary. Most colonies are requeened annually or every other year, but this one was reared in my first year in Scotland (2015) 3.

I popped the lid off both colonies and examined them in greater detail. It wasn’t the recommended ‘shirtsleeve weather‘ by a long-shot, but I feared the worst and didn’t think a bit of cold would do these two any further damage.

Unfulfilled promise

The nuc contained about a cup full of bees and a small, unclipped pale queen.

Overwintered virgin queen?

Overwintered virgin queen?

This definitely wasn’t the queen I’d put in the box last August. For whatever reason, the colony had clearly replaced the queen late in the year. It hadn’t swarmed, so it looks like they’d tried to supercede the old queen. Going by the total absence of worker brood I presume the new queen hadn’t mated successfully, or at all, and that she was a virgin.

She wasn’t running about skittishly like new virgin queens do, but she wasn’t doing anything very useful either.

There were a few drones in the colony and one or two sealed drone cells. Whether these were from unfertilised eggs laid by the queen, or laying workers, is largely irrelevant 4. The colony was doomed …

Worn out

The full sized colony was only full sized in terms of the hive it occupied. Inside there was another rather pathetic cupful of bees together with a very tatty, marked and clipped queen 5. There was more paint on her head than her thorax and I remember marking her with a very ‘blobby’ Posca pen. This was the queen I’d expected to find in the box.

Old and tired ...

Old and tired …

There were no drones in this colony, but no eggs either. There was also no sign of a second queen or evidence of attempted supercedure. I suspect the ageing queen simply ran out of sperm, stopped laying and never got started again.

Sometimes old queens turn into drone layers and sometimes they just stop. I’m not sure why they exhibit this different behaviour. It might actually reflect when they’re detected. I think I usually find drone laying queens a bit later in the Spring. Perhaps a failed queen starts laying (unfertilised) eggs only once the ambient temperature has risen sufficiently to help the much-reduced numbers of workers keep the brood nest warm enough?

That’s guesswork. It’s still cold here, with frost most nights. The small number of bees in the colony would have been unable to maintain the mid-30’s temperatures required for brood rearing. It’s surprising they’d survived this long.

Health check

Neither colony had any obvious signs of disease. The floor of the full hive was thigh-deep – if you’re a bee – in corpses.

Winter losses ...

Winter losses …

However, a good poke around through the cadavers failed to find any with signs of the deformed wings that are indicative of high viral loads. I hadn’t really expected to … the Varroa loads in this colony in the late-summer and midwinter treatments had been very low.

Corpses ...

Corpses …

Lose them or use them?

Clearly both queens had failed. Both were despatched. To keep them in the vain hope that they’d miraculously start laying again would have been a waste of time and, more importantly, other bees. The virgin would now be too old to get mated and there won’t be drones available here for at least 6 weeks.

This left the dilemma of what to do with the remaining bees. Both colonies were apparently healthy, but too small to survive. In the autumn the obvious thing to do is to unite small healthy colonies with large healthy colonies. This strengthens the latter further and helps them get through the winter.

However, this is the Spring. There were probably no more than 300 bees in either of the failed hives. All of these bees would have been at least 3 months old, and quite probably significantly older. They were unlikely to live much longer.

Furthermore, uniting these small colonies with larger colonies in the apiary would have caused disruption to the latter and increased the volume of the hive to be kept warm. Neither of these are desirable.

I therefore shook both small colonies out allowing the healthy flying bees to redistribute themselves around the half dozen strong hives in the apiary. Before shaking them out I either moved the original hive altogether or – in the case of the nuc from the shed – sealed the entrance, forcing them to look elsewhere for a colony to accept them.


Colophon

The term dud is used these days to mean a “thing that fails to function in the way that it is designed to”, with this usage dating back to the 1914-18 war where it referred to shells that failed to explode. However, the word is much older. Its original meaning was a cloak or mantle, often of coarse cloth, with references to the word dudde dating back to the 14th Century. Over the next few hundred years the meaning, in the plural duds, evolved to mean clothes and – more rarely but more specifically – ragged, shabby clothes or scraps of cloth. This seemed appropriate considering the tatty state of the old marked queen …

 

 

Apivar & Apitraz = Amitraz

The range of miticides available ‘off the shelf‘ to UK beekeepers has recently been increased by the introduction of Apitraz and Apivar.

‘Off the shelf’ because, until recently, these were only available with a veterinary prescription.

Considering the extensive coverage on this site of oxalic acid-containing miticides and more recent posts about the – regularly ineffective – Apistan, it seemed fair and appropriate to write something on the active ingredient and mode of action of these new products.

Mites on drone pupae ...

Mites on drone pupae …

Conveniently, because the active ingredient is identical, these can be dealt with together in a single post. The similarities don’t end there. The amount of the active ingredient is the same and the way it is administered is very similar. They are different commercial products; Apitraz is distributed by Laboratorios Calier, SA and sold by BS Honeybees, Amitraz is distributed by Veto Pharma and sold by Thorne’s. The strips have a different appearance and a slightly different mechanism by which they are hung in the hive.

They even cost about the same – a single packet of 10 strips (sufficient to treat 5 hives) costs £30.50 and £31 respectively for Apitraz and Apivar.

Amitraz

The active ingredient in both Apitraz and Apivar is Amitraz.

Yes … I find these three names confusing similar as well 😉

Amitraz is a synthetic acaricide – a pesticide that kills mites and ticks. It was discovered and developed almost 50 years ago by the Boots Co. (the drug development predecessor of the Boots the Chemist 1 found in most high streets). Amitraz is the active ingredient in a range of medicines approved by the Veterinary Medicine Directorate, including Aludex and Certifect, both of which are used to treat mange in dogs.

Amitraz

Amitraz …

For completeness I should add that Amitraz used to be used by US beekeepers and was sold as a generic pesticide under the name Taktic, though this was withdrawn in about 2014. I believe that Apivar is now available as a slow-release Amitraz-containing Varroa treatment in the US.

Mechanism of action

Amitraz has to be metabolised (essentially ‘modified’) before it is active. This modification occurs much less well in bees than in mites. In fact, the toxicity of Amitraz for bees has been determined to be about 7000 times less than in mites.

Once converted into an ‘active’ form the most important mechanism of action for Amitraz is through interaction with the alpha-adrenoreceptor and octopamine receptors of Varroa 2.

OK, since you asked … octopamine receptors normally bind a neurotransmitter called – rather unimaginatively – octopamine. Quelle surprise as an apiculteur would say. It’s likely that occupancy of these receptors by Amitraz triggers a series of so-called downstream events that change the behaviour of Varroa. Similarly, amitraz also acts as an agonist 3 when binding to the alpha-adrenoreceptor which normally interacts with catecholamines. This results in neurotoxicity and preconvulsant effects.

That all sounds a bit vague. Essentially, amitraz binds and activates receptors that are critically important in a range of important aspects of the Varroa activity and behaviour. Remember here that the mite is entirely dependent upon proper interaction with the bee to complete the life cycle. For example, if the mite fails to enter a cell at the correct time or doesn’t hitch a ride on a passing nurse bee for a few days, it will likely perish.

Amitraz changes behaviour and so exhibits miticidal activity. It has additional activities as well … these multiple routes of action may explain why resistance to amitraz is slow to develop. More on this later.

Usage of Apitraz and Apivar

Both Apitraz and Apivar are formulated as plastic strips impregnated with amitraz. The bees must come into contact with the strips to transmit the amitraz around the hive. Two strips are therefore placed between frames approximately one-third of the way in from each side of the brood box – typically between frames 4 & 5 and 7 & 8 of an 11 frame box. This assumes the bees occupy the entire box. If they don’t, arrange the strips in the appropriate part of the box with 2 frames separating them. Both types of amitraz-containing strips have a means of securing them hanging between the frames.

The recommended treatment period is 6 (Apitraz, or Apivar with little/brood present) to 10 weeks (Apivar with brood present). As with Apistan, treatment should not be applied during a honey flow or when honey supers are present. Further details are included on the comprehensive instructions provided with both products. There’s also a reasonable amount of information on this New Zealand website for Apivar.

Efficacy

This is the good bit … very, very effective. When used properly, amitraz-containing miticides can kill up to 99% of the Varroa in a colony.

Toxicity and wax residues

The good news first. Amitraz does not accumulate in wax to any significant extent. It is not wax-soluble. This is in contrast to Apistan which is found as a contaminant in most commercially-available beeswax foundation.

And now the bad news. Beekeepers also have alpha-adrenoreceptors and octopamine receptors. So do dogs and fish and bees. Although amitraz has increased specificity for the receptors in mites and ticks, it can also interact with the receptors in other organisms. Consequently, amitraz can be toxic. In fact, if you ingest enough it can be very toxic. Symptoms of amitraz intoxication include CNS depression, respiratory failure, miosis, hypothermia, hyperglycemia, loss of consciousness, vomiting and bradycardia.

And it can kill you.

Admittedly, the doses required to achieve this are large, but it’s worth being aware of what you’re dealing with. Amitraz-containing strips should be used only as described in the instructions for use, handled with gloves and discarded responsibly after use.

Resistance

Multiple modes of action makes it much more difficult for resistance to evolve. But it can and does. Resistance to amitraz is well-documented and is understood at the molecular level. However, this is in cattle ticks, not Varroa.

At least, not yet, though there are numerous anecdotal reports of Varroa resistance.

I’ll deal with resistance in a separate post. It’s an important subject and avoiding it is a priority if amitraz-containing compounds are going to remain effective for Varroa control.

Cost

At about £6 per colony, amitraz-containing treatments are not significantly more expensive than the majority of other approved miticides, perhaps with the exception of Api-Bioxal which is appreciably less expensive (though more restricted in the ways it can effectively be administered 4).

Apivar ...

Apivar …

When you purchase a couple of packets of Apivar – enough for 10 colonies – it might feel expensive 5. However, it’s worth remembering that this is still less than the likely ‘profit’ on a couple of jars of your fabulous local honey per colony per year, which seems pretty reasonable in the overall scheme of things.

And, if you look after your colonies well, you are maximising the potential yield of honey in the future … so you’ll be able to afford it 😉