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