An old disease with now new solutions
James E. Tew
Tempus fugit
Time flies. Since 1974, I can document publishing more than 600 beekeeping articles for the popular media. This collection does not make me special, nor am I a record-setter. Others have written and accomplished much more. But what my multitude of published bee article contributions makes me understand is how much time has passed and how quickly it passed – and how much things have changed – or not.
In 2011, I wrote a piece that I have always remembered. I hope you, the reader, will not take offense, but most of my articles are “for the moment.” A year later, or so, I have few specific memories of many of my articles. Forgettable – right? But “Keeping Bees as best we can – with what we know,” has been one article that I have always remembered. In that article, I wrote that we had, “lots of questions with few real answers,” and that as beekeepers we were, “keeping bees in the gap.” By “gap,” I meant that we were being forced to routinely make management decisions in the gap between a question and its answer. I find myself in this reminiscing state-of-mind because one of my colonies has European foulbrood – again. Different year. Different colony. Same disease. I’m back in the gap. I am in the space between the question, “What do I do about European foulbrood” and that question’s mostly non-existent practical answer.
European foulbrood then
When I began beekeeping in the early 1970s, European foulbrood (EFB) was a prominent “legacy” disease that was well documented in the beekeeping literature. During those days, the primary concern about EFB was distinguishing it from American foulbrood (AFB) which was (and continues to be) a much more serious malady. At that time, the answer to the question, “What do I do about European foulbrood?” was to treat EFB colonies with three doses of Terramycin and the gram-positive, non-spore forming, bacterial disease would clear up. If not, treat with three more doses and it would either clear up or Winter would be approaching, and the self-limiting disease would fade away on its own. If the disease reoccurred the next season – you know the drill – treat with Terramycin. The antibiotic was cheap and was readily available from bee supply sources. Antibiotic application was a routine beekeeping procedure.
European foulbrood now
As you know, Terramycin, and antibiotics in general, are now much more restricted within beekeeping and within society in general. To use them, beekeepers are required to get a prescription from a veterinarian. I’ve never done that, and I don’t really know how to tell you how to find such a beekeepingly-educated person. Currently, I don’t see that as my purpose here.
For several decades, we had an imperfect solution for controlling EFB. Antibiotics. The clear reality is that I do not have access to bee antibiotics now. (As a hobby beekeeper, I sense that I probably never should have had such access.) So now, I am in the EFB gap. I have the question, but I do not have the answer.
The diagnosis
This season, I knew one of my package colonies had a drone layer. The last time I checked the other packages, they were all thriving. One package colony almost immediately replaced its queen, but it did so successfully and was now rushing to catch up. All seemed good this Spring and Summer.
As I opened what had heretofore been a thriving package colony, I was met with the characteristic smell of decay and spotty brood pattern of a failing colony. This is a beekeeper moment that only comes with experience. My first thought was, “Oh my stars, is this American foulbrood!” I admonished myself to stay calm and to form an enlightened diagnosis.
Essentially only larvae were affected. From this characteristic and from other symptoms, I voted against AFB. But now, there is a new kid on the bee disease block – Bee Parasitic Mite Syndrome (BPMS). It was a reasonably quick call to decide that, while varroa mites may have been the EFB vector, this colony was not collapsing from a massive Varroa infestation. Nope. This is a case of European foulbrood – again. I had an outbreak in two colonies three years ago. Both died.
At that moment, as I stood by the colony, I did not care that the name of the causative agent had changed multiple times in the past decades. As I stood by the colony, I did not care (much) at what stage the larvae is in when it dies. As I stood by the colony, I did not really care that it could have been infected bee bread that caused the illness. I wanted one clear thing – just one thing. I wanted to know what to do help this ailing colony recover – right now. Yet, that information was not available, but I was given some suggestions (guesses) that were thought to help. Thanks. Welcome to the frustration of decision-making in the gap.
The modern-day EFB treatment conundrum
This colony’s EFB case was advanced. Part of the colony’s problem was that it had a beautiful, productive queen. She was producing major amounts of brood, and much of it was diseased. The brood patterns were nicely formed. Multiple frames have been filled with brood. This was a good queen that was producing copious amounts of diseased brood.
Antibiotics
In the old days, I would most likely have had some antibiotic product on hand. Back then, having a powdered sugar mix at the ready, was perfectly normal colony management. During the halcyon days of antibiotic beekeeping, the procedure was: (1) See the disease – (2) Treat the disease with antibiotics – and (3) End of the disease story (so to speak).
But this is today. The procedure would go something like this: (1) See the disease. (2) Stop everything. (3) Contact a veterinarian who participates in the bee health program. (4) Wait for a return call. (5) Get a prescription (I suppose). (6) Get the script to a supplier. (7) Mix and apply material. (8) Wait and watch. Days have passed – maybe even weeks. From my view, for hobby beekeepers, antibiotics are no longer a quick fix. They probably never really were.
So, for a EFB gap beekeeper, I’m comfortable writing that antibiotics are not practical. But the use of antibiotics is still possible. For full instructions, see: Dr. Chris Cripps’ thoroughly written Bee Culture article at: “Do I need a vet for my bees?” https://beeculture.com/do-i-need-a-vet-for-my-bees/
Requeen the EFB afflicted colony
Of course, requeening the sick colony is a common suggestion. For most of us, blaming (or praising) the queen’s performance is a universal approach to many modern bee colony management recommendations.
In this instance, for EFB management, it is thought that the break in brood rearing gives worker bees in the sickly colony time to remove diseased larvae and to clean the cells in preparation for new healthy offspring.
Additionally, it is suggested that the queen’s progeny was genetically susceptible to European foulbrood – to a greater or lesser extent. Ideally, the new queen would fortuitously produce future progeny that was more resistant to European foulbrood – but there is no guarantee. So, while this is a rational plan, you are going to be out of time and money for buying and installing the new queen – all without a promise of improved EFB genetic resistance.
To get a grip on the huge picture of typical annual bee colony management, I sense that beekeepers break that big picture into smaller ones. So, in one instance, maybe I am worrying about swarming, while in another smaller picture, I am concerned about controlling robbing behavior. Even later, I wonder what to do about Varroa populations. As are most management topics, these examples are all interconnected. They do not truly stand alone.
When I replace the queen in my EFB-infected colony, I am addressing EFB pathogens, but I am also unintentionally affecting this colony’s ability to gather stores for Winter. Its worker population will have been stunted by the queen replacement procedure. But this colony would have had foraging problems anyway – too much of the queen’s brood output is already undersized or outright dead. Adding to the morass, there is yet another variation on the disease control theme – by replacing the queen and causing a brood break, I have unintentionally set back the in-hive Varroa population. While I was trying to control EFB, I did a pretty good job of lowering Varroa populations. Am I practicing queen management or am I controlling varroa? Oh, wait! I’m supposed to be trying to control European foulbrood.
Destroy diseased brood combs
Another common recommendation is to destroy all brood combs in the sick colony. While I am inclined to implement that recommendation, that does not mean that I do not feel some pain as I destroy six or seven brood frames with a beautiful pattern of sickly brood. Good queen, but bad brood results.
A perfunctory review of the function of a burn pile in the apiary rarely gets mentioned, but it should. The typical burn pile is an important beekeeping tool. Destroying diseased frames of combs, destroying old combs with too much drone comb, burning broken frames, or disposing of spent hive bodies, are some examples of the usefulness of the “burn pile.” No bee disease can contend with fire. Burning diseased combs is usually a good idea.
My EFB – my problem
I know. My EFB challenge is actually my bees’ problem but seemingly my bees are losing this battle. I need to step in. It’s what I do. I’m a colony manager, but exactly what should I do?
- I will destroy about eight brood frames and reduce the colony to a single deep.
- I have already been feeding thick sugar syrup to simulate a nectar flow.
- The queen. What to do with her? In order to stop brood production, I removed (caged) her from the colony and have allowed the colony to start the process of emergency queen production. That is the cheapest move I can make.
I can’t take credit for #3 above being all my doing. Yes, I caged the queen and left her in the colony. I only wanted to see if the colony’s level of hygienic activity would quickly go into high gear with the queen out of circulation.
I returned five days later, mentally prepared to find a dead caged queen. She was fine, but with the colony still showing signs of diseased larvae, the nurse bees had started numerous emergency queen cells on a small amount of remaining brood. It was a “humph” moment for me in the yard. Rather than release the queen back into her own colony, I would permanently remove her and allow the bees to finish what they had started – building a new queen and cleaning the final remnants of the EFB infection. That would require me leaving a couple of diseased brood frames in the colony on which the queen cells were developing.
My ulterior motive
In yet another of my package colonies having an entertaining story, is a colony that has a beautiful, marked, drone-laying queen. Classic. Just classic. In some ways, like the EFB queen, the drone layer is producing prodigious amounts of brood – but it’s all drones. I should have addressed this issue several weeks ago, but honestly, I kept it for photographic purposes. How about I try this move – I replace the drone-laying queen with the EFB queen? Gasp! Gasp! Choke!
White1, in his classic EFB bulletin produced in 1920, wrote, “European foulbrood is not likely to be transmitted by queens or drones. Whether they ever do so has not been demonstrated.” While I did nothing that could be called a thorough EFB literature review, what I did perceive in my web-based review is that other than making antibiotics nearly impossible to use in my hives, few advances have been made in managing this disease. As antiquated as I might sound, returning to classic, pre-antibiotic scientific information has practicality.
It’s not just EFB . . .
European foulbrood is not the only bee disease with an uncertain course of action. In reality, beekeepers do not have a definitive protocol for any bee disease or pest. So bottom-line, when I find European foulbrood in my colony, I can plan on that colony being a marginal player in my apiary. In fact, it has a good chance of dying. I can requeen and fiddle with combs. I can feed. I might even resort to antibiotic use, but when all is considered – for this season – this colony will not be a producer this season. I sense that the most I can hope for is for it to be strong enough to survive the looming Winter.
My saga is not new. EFB issues have always been like this. During recent decades, it could be said that we have gone a bit backwards. The upside of my situation is that at least my colony had EFB and not American foulbrood (AFB). That would have been much worse. See – things are not all bad.
Dr. James E. Tew, Emeritus Faculty, Entomology, The Ohio State University and One Tew Bee, LLC
tewbee2@gmail.com
https://www.honeybeeobscura.com
1White, G.F. 1920. European Foulbrood. United States Department of Agriculture. Bull. No. 810. Government Printing Office. Washington. 47 pp.
