1st Honey bee pests, diseases and poisoning revision post: EFB and AFB

This is a 1st revision post for the British Beekeeping Association’s Module 3 Honey bee Pests, Diseases and Poisoning exam, which I plan to take in March. This year I’m doing the correspondence course, so I have a tutor who will set me papers and give me comments on my answers. Here’s my attempt at the first paper set.

Section A 

A1.   i) list the notifiable bee diseases and pests in the current UK and European legislation

The Bee Diseases and Pests Control Orders 2006 for England and for Wales lists the notifiable diseases and pests:

  • American foul brood (AFB)
  • European foul brood (EFB)
  • Also, the pests Small hive beetle (Aethina tumida) and Tropilaelaps spp. mites, which are not yet in this country and we must be alert for.
Tropilaelaps mite

A varroa mite on the left, compared with a Tropilaelaps mite on the right. Courtesy The Food and Environment Research Agency (Fera), Crown Copyright.

ii) who do you notify if you suspect one of  your colonies has a notifiable disease or pest?

Your local government National Bee Unit inspector. All beekeepers in England, Scotland and Wales should know who their local inspector is. If not, see the Beebase Contacts page to find out.

A2.   why are combs with suspected EFB no longer sent to the National Bee Unit laboratories for confirmation?

Hmm; I’m going to guess that this is because inspectors now carry lateral flow test kits with them in the field.

A3.     with what other diseases or conditions can EFB be confused

European Foul Brood is an e(arly) bacterial brood disease, so it affects mainly unsealed brood. EFB bacteria mass inside the gut of an infected larvae, which can cause death from starvation. When an uncapped larvae dies it lies in an unnatural attitude suggesting pain – twisted spirally around the walls, across the mouth of the cell or stretched out lengthways.

Infected larvae are discoloured yellow-brown and have a ‘melted appearance’, with loss of their usual segmentation. Some dark sunken cappings may be present, but the cell contents will not form a rope with the matchstick test. The dead larvae form scales that can be easily removed by the bees. The brood pattern will often appear patchy and erratic as dead brood is taken out by the workers.

EFB may be mistaken for:

  • AFB, some strains of which kill uncapped larvae and form scales – but unlike EFB scales, AFB scales are difficult to remove. Sometimes EFB larvae make it through to the sealed brood stage before dying, when there may be greasy, perforated sunken cappings similar to AFB – however the contents underneath the cappings are usually quite different.
  • Parasitic mite syndrome caused by varroa infestation – dead larvae/pupae which die at the uncapped brood stage discoloured brown or black, watery or firm, eventually drying to a scale similar to EFB which can easily be removed. Newly emerged bees are often deformed or have deformed wings. As with EFB, there will be a poor brood pattern.
  • Chilled brood, which causes dead brood usually present in all stages, especially at the edge of the brood nest – unsealed brood turns very dark brown or black in colour before drying up.

Can anyone think of any others?

EFB testing – shaking

Emma and I found out in April just how easy it is to confuse EFB with other diseases. In my post ‘Trouble in bee-land‘ I took some photos of what I thought might be EFB or another brood disease. A lot of other commenters who looked at the photos agreed with me. However, Andy Pedley got a negative result using a EFB testing kit and concluded that the brood had become chilled.

A4 if EFB is present in a colony in Spring why does it appear to disappear in summer? 

If larvae are well fed, and can manage to take in enough food to feed both themselves and the EFB Melissococcus plutonius bacteria, they can manage to survive with EFB bacteria in their gut. As the brood nest reaches its peak in size in mid June the nurse bees will be stretched to feed all their charges, so EFB may claim more victims. Once the brood nest reduces in size later in summer, an efficient colony will be better able to feed its larvae well and the disease will ‘appear to disappear’. A good nectar flow is crucial for this.

A5.     in the USA antibiotics are routinely used prophylactically as well as to treat colonies with AFB.  What are the dangers of such a practice?

I had to look up what ‘prophylactically’ means – the dictionary says “Acting to defend against or prevent something, especially disease; protective.” This is not something I’m familiar with, as the treatment for AFB here is to destroy an infected colony through burning, and I believe using preventative antibiotics against AFB is illegal.

I read online that although antibiotics can be effective at preventing infections from establishing they can also suppress the visible symptoms of AFB, thereby masking an infection. Some antibiotics, including the tetracyclines, do not kill the bacterium causing AFB, they just stop it multiplying – hence the lack of visible signs.  Meanwhile the disease could be spread to nearby hives while the beekeeper remains unaware that AFB is present.

There are also reports of AFB bacteria developing resistance to Terramycin (oxytetracycline) antibiotic in honeybee colonies in parts of the world where it is routinely used against diseases.  Additionally treating can weaken the hive, because Terramycin may kill a percentage of the brood.

Printer-friendly pdf version

Burning an AFB infected colony, the control method used in the UK. Courtesy The Food and Environment Research Agency (Fera), Crown Copyright.

This is only the first section! Will try to do the second section tomorrow.


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.
This entry was posted in Disease prevention, Exams and tagged , , . Bookmark the permalink.

26 Responses to 1st Honey bee pests, diseases and poisoning revision post: EFB and AFB

  1. It is so interesting to read about your studies. I wish we had such courses here in the USA. In the US, people are coming to realize the dangers of using antibiotics regularly in hives and many beekeepers are going a more natural and chemical-free route. I thought it was interesting that it was a question because I think ALL American beekeepers could really benefit from that realization. One of the many reasons it would be great if we had some sort of certification course as you do. I think it would inspire more responsibility. More beekeepers doesn’t always mean BETTER beekeepers.


    • Emily Heath says:

      To be fair, many of the US beekeepers whose blogs I follow use no chemicals or treatments at all in their hive. I do use Apiguard (thyme based) and oxalic acid (a compound found naturally in plants like rhubarb) for anti varroa treatment. I wonder if it is the commercial beekeepers using these antibiotics routinely.

      I think the BBKA exams are great as they help you learn info you’d never learn from just opening the hives up. You need the practical experience too, but the exams give you a scientific background which helps enhance the practical knowledge.


  2. pixilated2 says:

    You make me feel better for making the choice not to put ANYTHING in my hives. I have had my colony in a TBH for almost 4 years and they are going strong and looking beautiful without my interference.

    We see resistance to antibiotics in human bacterial infections due to misuse, so why wouldn’t we see the same resisting response in infectious bee organisms? Also, the information you shared about burning hives with AFB makes sense when you think about it… Though it would be sad to faced with that prospect. Thanks for sharing this with us!
    ~ Lynda


    • Emily Heath says:

      Hi Lynda,

      Glad your bees are doing well. I do use Apiguard (thyme based) and oxalic acid (a compound found naturally in plants like rhubarb) for anti varroa treatment, but they are not antibiotics. Luckily not many hives here become infected with AFB – probably more would if inspectors treated rather than immediately burning.


    • Deb Weyrich-Cody says:

      Hello Emily and Lynda, Regarding antibiotic treatment of AFB infected hives… Once infected there is no turning back and destruction is absolutely the only way to stop further spread; antibiotic action is useful only to prevent infection. Lynda, I Ieft a (PFAF)link for Goldenrod on your post and believe it mentions something about antibiotic action. If this is so, I’m guessing that there are other plants that bees already use to self-medicate as well… From that assumption, I’d say that the pre-emptive method/prophylactic application of Oxytet(racycline) is once again poking our noses into the bees’ business when it’s not necessary and a healthy hive will not succumb to disease, but instead have natural resistance – a strong immune system, if you will.
      Good on you Emily, for working WITH Nature, not against her! I only pray that more beekeepers worldwide will take up the natural methods of keeping healthy, strong hives.
      Here’s to healthy living for us all! Cheers, Deb


  3. Correction: there are Small Hive Beetles in this country! They are to be found at a place called Sand Hutton near York. You have to walk through a refrigerated corridor and undergo security checks to see them.


  4. Good luck with your testing Emily. It really is a lot to remember and be familiar with. I keep reading about bee ‘troubles’ in the UK. Is it worse there than elsewhere?


    • Emily Heath says:

      Thanks 🙂

      I don’t think it is worse here than other countries, for instance we don’t officially have problems with colony collapse disorder, and nasty pests like the small hive beetle aren’t bothering us yet. Varroa is the worst problem, and also the bad weather this year, which may be a result of climate change. The UK is a very densely populated country, so there is probably more competition between hives for limited amounts of nectar too.


      • Does not climate affect the stresses on the hives, making weaker bees more susceptible to disease and parasites? Just asking because I really don’t know other than what I read on your site and Emma’s site. I did not know that you officially did not experience colony collapse. Lucky too. It really is a complicated and ill defined issue.


        • Emily Heath says:

          Yes – if the bees are trapped inside for days at a time, then one of the problems is they will have difficulty collecting pollen. We were giving them sugar syrup to replace nectar, but really they need pollen too to provide protein, which is necessary to feed the brood and help bees develop properly. Bees which receive a less nutritious, varied diet will be more susceptible to disease. We could buy in pollen patties but there is the risk that pollen collected from other hives could spread disease to our bees.


          • Hi Emily, I saw a snippet on a beekeeping board on research in progress by Dr. Diana Sammataro (USA) in which she was exploring the impact of honeybee feed sources on Varroa levels. To her complete surprise (comparing wild fed vs. real pollen fed vs. pollen substitute fed colonies) the brood in the pollen substitute fed hives was infested with 5x more mites than in the other two groups…horrific. She is in the process of re-running the study now to see if the results hold up for replication. Meanwhile, I tossed all my pollen substitute patties!


            • Emily Heath says:

              That is terrifying. I wonder what the link could be, as I was thinking perhaps AFB/EFB could be transmitted through pollen patties, but not varroa, as surely live mites wouldn’t be in the patties? Or is there a link between pollen substitute and poor nutrition, perhaps the pollen substitute just doesn’t do the job and this weakens the colony?


  5. Anna says:

    I always like when you do the revisions, I end up learning along with you.


  6. whitt98 says:

    Always enjoy your posts – and I learn things which is bonus. Good luck on your next round of exams. Here in Sacramento, California it is just turning to autumn, lovely warm days, cool evenings. My bees are still very active.


  7. I’ll be book marking this post for future reference. Very useful. Good luck with the exam.


  8. P&B says:

    Thank you very much. As a novice beekeeper, I have learned a lot from this post.


  9. I am going to really benefit from your revision posts now on the road to my first module. Another great post, Emily!


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