Notes from a talk by Norman Carreck – colony losses, native bees, pollen diversity and the small hive beetle

Yesterday I went to a talk by Norman Carreck, which was organised by the London Beekeepers Association (LBKA). One of the great things about being a beekeeper in London is being able to hear expert speakers like Norman. He is currently Science Director of the International Bee Research Association (IBRA), based at the Laboratory of Apiculture and Social Insects at the University of Sussex.  He has kept bees since he was 15, obtained the National Diploma in Beekeeping in 1996, is a member of the Technical and Environmental Committee of the British Beekeepers Association, a member of the Examinations Board for the National Diploma in Beekeeping, a member of the “Bee Health Advisory Forum” for the Defra “Healthy Bees Plan”, the UK member of the Executive Committee of the international honey bee research network “COLOSS” and Senior Editor of the Journal of Apicultural Research.

Norman Carreck

Norman Carreck

Despite all Norman’s achievements he came across as an unassuming and modest speaker, who took plenty of time to answer everyone’s questions afterwards. His talk was about research projects carried out by COLOSS  (which stands for Prevention of honey bee COlony LOSSes), on the themes of colony loss monitoring, local bee vs imported bee survival, pollen diversity and the small hive beetle.

How COLOSS works

It’s an international, non-profit association set up following the publicity surrounding colony collapse disorder in 2006, when many beekeepers first reported losing large numbers of colonies. There are 722 members in 89 countries worldwide, with membership open to scientific professionals interested in the well-being of bees. COLOSS holds regular meetings, but has very little money, so the individual members fund themselves to attend. Norman told us that in a way this lack of money is an advantage – as it means members aren’t competing with each other for central funding from COLOSS, which encourages mutual cooperation.

Colony loss monitoring

To try to gather data to establish whether honey bee losses are a genuine global phenomenon, COLOSS members came up with a standardised questionnaire for beekeepers. A lot of thought went into the questions in order to take account of the differing lengths of international beekeeping seasons and practices. Norman mentioned that although both the British Beekeeping Association and National Bee Unit do annual surveys which ask beekeepers some of the same questions, COLOSS has had difficulty getting the results of these surveys – which has been a frustrating situation.

A female varroa mite - © Crown copyright 2010 "Courtesy The Food and Environment Research Agency (Fera), Crown Copyright"

A female varroa mite – © Crown copyright 2010 “Courtesy The Food and Environment Research Agency (Fera), Crown Copyright”

The surveys carried out so far indicate that colony losses do in general seem to be higher than 30 years ago – but there are no obvious patterns to this – with losses varying between countries from year to year. Climate itself doesn’t appear to be a big factor, as beekeepers have developed their own systems to cope with their particular climates. Weather is important but doesn’t explain all the losses. Varroa is very important, with higher losses occurring when beekeepers don’t treat against mites. Areas of intensive agriculture also tend to have high losses – this may be due to a lack of forage diversity for the bees, particularly at times of the year when the main farming crops have finished flowering. The most recent results available are for losses over the 2014/15 winter.

Are people keeping bees suitable for where they live?

COLOSS scientists wanted to compare how successfully individual strains of the European honey bee (Apis mellifera) cope in a range of environments. To do this they set up an experiment comparing 16 genetically different strains at 21 locations, across 11 European countries. At each location, a local strain of bee was compared with two other strains. For three years, six colonies of each strain (so 18 in total) were monitored for honey production, disease, colony size etc at each site. They were not treated for varroa, which meant several died early on.

The results of this study were published in a number of papers, including ‘The genetic origin of honey bee colonies used in the COLOSS Genotype-Environment Interactions Experiment: a comparison of methods‘ (Francis, 2014) and Honey bee genotypes and the environment‘. Across all the locations, there was no one strain that consistently had better survival rates. BUT there was a statistically significant difference between the survival rates of local and non-local bees – local bees survived longer. One reason for this could be that local bees have adapted to cope with local strains of pathogens. Whatever the reason, the study indicated that local bees do better. Food for thought for beekeepers who regularly import queens from the other side of the world or buy in packages from hundreds of miles away.

Andrew Abrahams

Andrew Abrahams

There has been some doubt over whether it’s possible to keep your bees pure, considering the queen honey bee will mate with as many local drones as can catch her. Andrew Abrahams is the only beekeeper on the Isle of Colonsay in Scotland and asked one of the Scottish heritage bodies for assistance in getting legal protection for his dark European honey bees. He was initially refused it and told bees shouldn’t be on the island at all, but eventually he won protection in a new Scottish government order which makes it an offence to keep any honey bees on the islands except the dark European honey bee, Apis mellifera mellifera. For more on this, see:

I notice Andrew runs beekeeping courses on the island. My husband Drew spent many summer holidays as a child on Scottish beaches, including stays on Colonsay… hmm maybe he can be persuaded that we really need to show our new baby the beauty of the Scottish islands and their wildlife!

Anyway, a study on the ‘Genetic integrity of the dark European honey bee‘ (Pinto et al 2014) confirmed that Andrew Abraham’s bees are pretty pure Apis mellifera mellifera; more surprisingly, even openly mated bees from Sussex University campus had a lot of Apis mellifera mellifera in them. Local strains survive well. COLOSS are currently putting together a book on sustainable bee breeding, to advise beekeepers on making the most of the bees we have rather than importing them.

Pollen diversity

CSI Pollen logo

In 2014 COLOSS began a “C.S.I. Pollen” study asking beekeepers to help collect data on the diversity of pollen collected by their bees. To take part, each beekeeper needed three colonies, each fitted with a trap to collect pollen on ten dates over a year. After each collection, the beekeepers were asked to separate out 20g of the pollen on a white tray and count the number of different pollen colours they could see.  Norman commented that this is not a perfect test as one plant may produce pollen grains which look like different colours (for example maize pollen is darker when wet), but at least all the beekeepers have done the sampling in the same way, so the data is standardised.

During 2014, 465 beekeepers in 24 countries took part. The initial data gathered from English and Welsh beekeepers during 2014 indicated that pollen diversity declined as the beekeeping season went on. The study was expanded during 2015, with many more beekeepers from 27 different countries taking part. The original data is still being analysed and a draft paper has been written.

The surveying will continue in some countries during 2016, including England, Wales, Scotland, Ireland and France. More volunteers are needed, so contact Norman if you’re interested.

Small hive beetle (Aethina tumida)

Like the Asian hornets, most UK beekeepers will be aware of these pests and the threat that they may reach us sooner rather than later. Norman described the beetles as “fairly repulsive things”, which make varroa mites look attractive in comparison.

Small hive beetle, Crown copyright

Small hive beetle, “Courtesy The Food and Environment Research Agency (Fera), Crown Copyright”

The beetle larvae hatch out in the hive and feed on comb containing pollen or honey, damaging the comb by tunnelling through it and defecating, which makes the honey ferment and run out of the combs. Heavy infestations of the larvae turn the combs into a sloppy mess that U.S. beekeepers call a “slime out”.

Once ready to pupate, the larvae leave the hive and burrow into soil, before emerging as adult beetles 3-4 weeks later. The adult beetles seek out bee colonies to mate in, then the females lay masses of eggs within cracks and crevices amongst the hive to start the cycle again.

One of the challenges in keeping the beetles at bay is that we don’t know how far the larvae travel to pupate. Norman could only say that they can wander “quite a long distance”. Additionally, the adult beetles fly – again we don’t know how far. More research is needed to confirm this.

1996, Florida
The beetles are native to sub-Saharan Africa, where they are a minor pest but not a serious problem. As usual the activities of humans moved them around the world, with the result that in 1996 beekeepers in Florida suddenly found their colonies full of the beetles. They wiped out many colonies and rapidly spread to several different states, where they remain today.

2004, Portugal
Beetles turned up in Portuguese colonies containing queens imported from the US (another reason not to import foreign queens). Some were discovered in the cages the queens had been released from. The Portuguese authorities moved quickly to burn all infested colonies and fortunately the beetles were eliminated.

2014, Southwest Italy
Beetles were discovered in Italy in 2014, causing panic. The Italian authorities started destroying lots of hives by burning, then sprayed insecticides to kill any beetles which might have been pupating underground. They found 61 infected sites and destroyed over 3,500 colonies. However, due to the sheer number of beekeepers in the area, not all apiaries were inspected.

Around 20,000 packages of bees were exported from Italy in 2014. In the UK our National Bee Unit inspectors tracked down any packages imported from Italy and inspected them – all were found to be clear of beetles. Other countries were not so thorough; for example the Polish government said it did not have the financial resources to inspect imported packages.

To try to help, COLOSS ran articles on the beetle in IBRA’s Bee World journal and organised a task force. A book called The small hive beetle in Europe which Norman has edited will be available soon. At a conference organised to debate the options available, it was clear that the patience of Italian beekeepers for the government’s policy of destroying hives was wearing thin. Compensation from the government took a year to arrive and then only compensated the beekeepers for colonies destroyed, not for loss of income from queen exporting or honey sales. Rumours began that beekeepers were not reporting beetles to authorities and quietly destroying infected colonies instead (or perhaps not destroying them).

2016, Italy
Some more cases were found in December 2015… with virtually all sightings including adult beetles, which indicates that they’re breeding. Norman suspects the chances of eradicating the beetles in Italy are slim.

Coping with the small hive beetle

African bees have developed strategies to deal with the beetles, for instance entombing them in propolis traps. European honey bees do this too, to a certain extent. So we don’t entirely know why they are such a problem for European honey bees. One theory is that African plants provide more propolis, so African bees just have more of it available to contain the beetles.

After the initial problems in the US, many beekeepers there have now learnt to live with the beetles. Sloppy beekeeping seems to be the main issue which allows the beetles to get out of hand and reproduce in vast numbers. Good apiary hygiene, such as processing honey immediately, not storing old comb/keeping honey combs in fridges or freezers, helps keep numbers low. Smaller hives also assist the bees in keeping beetles contained, as does not inspecting too often (beetles are released as beekeepers move combs apart and break propolis seals open).

Norman is sure the beetles will reach the UK eventually. They are attracted to the smell of rotting fruit and have even reproduced in rotting bananas under laboratory conditions. This means they could potentially move around the world in fruit consignments or pupating in pot plants, not just through bee imports.

They like dry, sandy soil, so damp, waterlogged clay soil like we have in some areas would deter them. They could potentially do well in the New Forest, which has light, sandy soil. Unfortunately the early detection methods we have are not good. Traps work well if you have lots of beetles; but if you only have one beetle in your hive there are plenty of other nooks or crannies it could end up in. Our WBC hives would be perfect for beetles to hide in!

See also…

The Laboratory of Apiculture and Social Insects at the University of Sussex, which Norman is based at, is running some workshops this summer/autumn. These are only £10 to attend and must be booked in advance as they are popular. You can choose from:

And a couple of videos of Norman lecturing:

This post is dedicated to my cat Bob, in honour of his steely determination to stop me typing it. 

About Emily Scott

I am a UK beekeeper who has recently moved from London to windswept, wet Cornwall. I first started keeping bees in the Ealing Beekeepers Association’s local apiary in 2008, when I created this blog as a record for myself of my various beekeeping related disasters and - hopefully! - future successes.
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14 Responses to Notes from a talk by Norman Carreck – colony losses, native bees, pollen diversity and the small hive beetle

  1. The small hive beetle runs rife through this area of Australia. We’ve had it here since about 2002. It was hoped that they’d die off in winter as they don’t like the cold weather, but of course bee hives are toasty warm all year. In spring and summer when they are active, they spread through colonies quickly. For backyard beekeepers, it’s a matter of staying on top of them with traps. If you don’t, in warm, humid years they can wipe out colonies. This year I’ve known several beekeepers who have lost their hives to slime out. All of them had their hives in areas with a lot of native forest and scrub.

    I see 2 main problems: For professional beekeepers, they can’t keep checking and changing traps – it’s just not feasible if you have 1000 hives. For hobbyists, it’s easy to think you’ve won the battle by reducing the numbers of beetles in your hives but they can (and do) live outside of the hives in summer so they keep re-infesting your hives.

    I personally would prefer small hive beetle to varroa – I would dread having both. Good luck keeping them at bay!


    • Emily Scott says:

      Thanks Laura! Norman briefly mentioned Australia during the talk and said that the beetle was doing well in coastal areas of Australia where the soil is damper, but not so much inland. They sound yucky but I think you’re right to prefer them to varroa, which is probably the bigger killer.


  2. The small hive beetle sounds dreadfully scary when our bees are already coping with varroa, viruses, fewer forage and mild winters/climate change. Lets just really hope another dastardly thing doesn’t reach our bees!


  3. Wow, Emily, really informative. I like especially the balanced nature of the surveys you have cited. All too often people want there to be only one cause, failing to understand how complex ecosystems are. Just one niggle for me though: the queen bee isn’t ‘promiscuous’ which tends to be a pejorative word especially reserved for human females. She does exactly what she should do to ensure the strength of her colony. In a way, perhaps human females are driven by the exact same instinct….


  4. Wendy says:

    Interesting post and a reminder again about how human activity has threatened honey bee survival. It is a worry about the small hive beetle coming to the UK seeing that it isn’t already eradicated where it’s found. Obviously I hope it isn’t inevitable. It is fascinating, too, to see the characteristics of the different strains of honeybee and Andrew Abraham’s isolated colony will make a great study. Looking at the photo, I wish my hives were in such a scenic location!


    • Emily Scott says:

      I hope it’s not inevitable too and that all the experts are being overly pessimistic. But then it’s even reached Australia, where they’ve done a great job at keeping varroa out so far.


  5. Very interesting Emily, thanks for this informative report.


  6. I really appreciate you keeping us up to date on the info. I prodded Kourosh as he has met someone over here who is looking for volunteers to monitor the pollen collection (he forgot to contact him but now he will!) Amelia


  7. Pingback: Notes from a talk by Norman Carreck – colony losses, native bees, pollen diversity and the small hive beetle — Adventuresinbeeland’s Blog | Premo from London Blog

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