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EFB options

40K views 258 replies 24 participants last post by  Gypsi 
#1 ·
I do a bunch of cutouts and I bring them to my home yard to monitor for a while before bringing them to my main out yard, just Incase anything unpleasant shows up. Good thing I do that, I’ve got one that is now showing classic EFB. Does not look like AFB. I did this cutout in March and they built back up ok, now filling 2 mediums nicely.
I know others have dealt with this, my first thought is get some terra pro. How do I find a vet for that elusive VFD? If I can get it cleaned up, I’ve got some fresh queens coming ready soon to requeen.
its just in the one hive, I have a second hive back there that’s inside a log. That one came home from the tree company about a month ago, and I don’t know it’s health since it’s inside a log. I was planning on doing a cutout on that one this weekend, and actually found my problem while getting things ready for that job.
 
#3 ·
If it is only in one colony, my once bit twice shy advice would be to destroy the frames and scorch the boxes. Some people have been lucky in cleaning it up with Oxy Tet but it apparently often comes back. Though treated the bacteria can remain dormant in comb for close to two years. I wish I had been more aggressive or had diagnosed earlier!
 

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#4 ·
Very smart move to keep those bees separate during a quarantine period.

(And if you've got a quarantine yard, treat it like one, too: separate gloves & tools, etc.)

Having dealt with documented EFB in my own yard, I would act aggressively: I would do a double shook swarm, on to different equipment, followed by treatment. I would shook-swarm the bees first into old (but presumed uninvolved) boxes, or even ones just cobbed together for the event. Then a three days later shook-swarm them, again, into a new set of permanent, equipment.

I would also treat the suspect hive and every hive in the same yard.

I would destroy the equipment I discovered the EFB in, as well as the first set of boxes in the shook swarm series. Just take the modest economic hit of losing one round of good equipment and the interim equipment for the first shook swarm (which could a cardboard nuc box) over getting multiple sets of permanent equipment contaminated. I have a lot of stuff in storage - at least a hundred boxes, thousands of frames, etc., dozens of bases, tops, etc., which is contaminated. I don't know when/if I'll be ready to risk using it again.

But I wouldn't do any of this without getting a positive result on one of the field test kits on the suspect hive. Because other things look like EFB.

Good luck - I don't mean that sarcastically, at all. I really do hope it goes well for you. EFB is addressed far too casually, IMO. It's presence in a yard can become a chronic problem that takes a few years to work its way out, even with treatment. I am hoping that this, my third season since it was found here, will finally be the conclusive turning point. But my foraging weather is poor this year, so I may have a re-occurence.

EFB sucks!

Nancy
 
#6 ·
EFB sucks!
understatement of the year nancy.

i am scrambling at this time dealing with an outbreak. 8 multi-year colonies surviving off treatments have been euthanized. 3 others have been moved to a quarantine yard.

i'm not sure where it came from, but discovered there are now at least 3 'new' beekeepers within flying distance of my yards with bees imported from out of the area, at least 2 of which have yet to get a colony through a winter. haven't made contact with the third one yet.

quadruple dang. will update my thread when the dust settles, if it even does.
 
#11 ·
There was an interesting video from the National Honey Show. At one time England euthanized colonies and had low rates of efb. Once again getting rid of susceptible genetics. Once they started treating and salvaging, rates went up. Also there are different types. Are all bees equally resistant to all types? I suspect not. Message, stop moving bees around between regions.
 
#12 ·
could this be the video you are referring to lharder?

https://www.youtube.com/watch?v=z0B9o4GHq7U&feature=youtu.be

(highly recommended viewing to anyone wanting to get up to speed on efb, and my starting point for further inquiry into some of the ground covered in the video)

it turns out there are 35 different 'sequence types' of efb. the various types are differentiated from each other using a molecular genetic technique referred to as 'mlst', which stands for 'multi-locus sequence typing'.

it appears that efb typing is being used to determine the course of action for remediation. choices include shook swarm, oxytetracylcline, or destruction (burning) depending on the efb type.

preventative measures such as arranging apiaries to minimize drift and avoiding the mixing and matching of equipment/resources are also discussed.
 
#15 ·
Yes that is the one. Destruction would work for all types and would be the default tf option. Once it hits (its just a matter of time right?), I guess destruction and aggressive removal of contaminated hives, and decontamination of comb using our ionization facility would be my course of action. And of course robbing screens to reduce drift. Those I hope to put on earlier that later this year as soon as I can make them. Perhaps, requeening together with shaking onto good comb could be used, but would leave more lingering doubt in my mind. I would not use antibiotics as they make bees more susceptible to other infections such as Nosema. I am just starting to read papers by Nance Moran about bee gut microbiota. Not sure if I would want to disrupt that in my bees as in theory it could be a destroying a valuable resource.
 
#13 ·
Common-place beekeeping techniques of moving frames to equalize hives, making up splits and nucs from mixed hive sources, adding a frames of brood when coping with LW, or a queenless hive, not keeping all equipment segregated to a single colony's hive stack, and bringing in new colonies such as cut-outs and swarms are all way EFB spreads. And none of those are indicators of piss-poor beekeeping or even unskilled beekeeping.

I am no longer keeping a full set of separate tools for each colony (since I've had no confirmed indication of EFB for a year.) But I have painted each hive a different color and I have a full set of equipment for each colony and now NEVER move any frames or boxes between hives. (That's how I inadvertently spread in the first year - equalizing brood and stores frames between hives in very early spring, before any problem was evident.)

And I keep pollen patty on the hives until well into early summer (past fruit blossom and dandelion.)

@Squarepeg, do you have lab confirmation, either from Beltsville or the field test kits? Are you having any success (or do you even want to considering your TF goals) locating a source of Oxytet? Oxytet stopped my active infection cold (in just 3 days), but it still left me with infected colonies and dirty boxes.

And I'll say it, in case you feel the same way: I was ashamed and blamed myself and I agonized over whether to treat, or not. And I dithered too long over the decision - kept going back to the idea that once I needed to treat I'd always be have to keep going, or that I was perpetuating weak genetics. My view these days is: if you've got a confirmed case, just do shook swarms on to clean equipment and treat immediately and move on. In other words: don't dither. Your bees have acquired a treatable bacterial infection. The cure for active infection is Oxytet. The best way to reduce equipment losses and to prevent long-term chronic disease is to get them off the dirty combs and into clean boxes ASAP. And make sure you don't allow any swarming from an infected hive. Do whatever you have to do to prevent that, as a point of public health. Use extreme cross-contamination infection prevention program (clean tools and gloves for each hive, every time). Close your yard to any beekeeping visitors, or if you allow visits, lend them clothing and tools which stay in your yard. Find every yard within your foraging area and warm other beekeepers to BOLO for the signs. Don;t sell or'give away hives, nucs, or queens. Make no increase, unless forced to stop a swarm, so as to reduce as much as possible equipment with known, or even possible exposure to an outbreak that will nee irradiation, or other aggressive handling to rid it of EFB contamination, in the short run.
 
#14 ·
many thanks for all that nancy, and also to those of you who took time to send pm's. it's times like these that being tapped into a first class community such as this one means everything.

cliff notes version:

positive field test by 'vita honeybee (european) foulbrood test kit'

reported outbreak to state apiarist

will provide state apiarist samples to run in his lab, as well as send some off to beltsville

oxytet prescription obtained from dvm and filled

self imposed strict quarantine, cancelled nuc orders

euthanized colonies less than five deep frames of bees

moved 3 infected but stronger colonies to a 'hospital' yard away from any known kept bees, getting their first round of oxytet tomorrow

(more detailed version to be posted on my thread when i catch my breath)
 
#17 ·
here are a couple of short videos from about 8 years ago presented by dr. jamie ellis, the gahan endowed associate professor of entomology in the department of entomology and nematology at the university of florida.

my take at this point in my review of the literature is that he is under-representing the impact of the disease at both colony and the apiary levels.

https://www.youtube.com/watch?feature=player_embedded&v=05tCHtUyNHM

https://www.youtube.com/watch?v=wyiaV222JoQ&feature=player_embedded
 
#21 ·
Instructions in case of brood diseases in Finland:
It is not allowed to use antibiotics in beekeeping. In case of EFB the use of antibiotics is also considered unnecessary and harmfull. EFB does not make spores and the main cause is colony stress.

Usually a colony with minor EFB outbreak will survive by itself, only give time to heal.
Serious outbreak will need about the same procedure as AFB.

In a small outbreak of AFB (just couple infected larvae): shaking bees to clean frames, and feeding with sugar.
Serious AFB: burning frames and bees, disinfection of boxes (flaming, Virkon S solution wash).

Sometimes EFB and AFB are hard to distinguish. Even laboratories have sometimes difficulties, because EFB bacteria grows so wildly, and there are so many different forms of it, that it can cover other, possible AFB, bacteria.
 
#23 ·
It seems that some sources can rightfully claim that EFB was/is easy to control. Now it appears to be coming to light that there are many different strains of the disease, some of which definitely are more virulent and persistant; easier to initiate and longer surviving on comb.

Up until about a year ago the ease of obtaining OxyTet and similar antibiotics and their use to routinely treat hives may have kept a lot of EFB (and AFB) hidden. I think there should be a lot more emphasis and awareness, esp. for new beekeepers and also many who have years in the business when the disease was rare and easily swept under the rug.

EFB is quite easy to spot when it is active but not so easy to identify at times when there is no brood. In other words easy to miss on a dead out. I am not sure yet about my diagnosis of suffocation by snow and dead bees blocking entrances. Could be EFB prevented the start of normal mandatory spring broodup. So far just storing those hives.

I have several nucs on order that I will set up on new equipment and watch them carefully.
 
#24 ·
Lots of good info here. Thanks.
I caught a whiff of smell coming from this hive the day before that concerned me. When I got the chance the next day, I put on the veil and brought the smoker and hive tool out. First frame showed dead developing larvae slumped down in the cells. There were scattered capped cells with apparently normal capping, not sunken at all. I grabbed a stic and tried the stick test on 7 or 8 and the contents of the normal cells came out milky white and not stringy at all. The dead open larvae also didn’t make the string. Quite a number of the dead larvae looked fairly mature and had that head up canoe shape I’ve read about with sac brood. Now I’m not as sure which I have, so I need to send in a sample. In the mean time,I’m going to shake them into a nuc and bag the combs and frames into the freezer, probably will end up burning them.
As soon as I got done inspecting, I carried my smoker back to the garage with the hive tool, washed my hands thoroughly (I inspect bare hand), scorched the hive tool and wiped the smoker down with alcohol (once it was out, because boom!)
Now I’ve got to clean all my cutout equipment even more thoroughly. Fortunately I haven’t done another yet. I usually bag cutout combs into the freezer then set them out in late summer to let the robbers clean it up. That bag is going right in my next fire.
 
#25 ·
#27 ·
SP, I have not had EFB or AFB in more years than I can count, but dealt with both in the past. EFB is easily cleared with oxytetracycline. Fortunately, most bees will eliminate EFB on their own if given time. I treated EFB with Oxy about 30 years ago and requeened the colonies. There were no recurrences.

The $65000 question is where did it come from. EFB can be brought in with infected equipment. It is far more likely that a nearby beekeeper had a colony collapse with disease that your bees robbed out.
 
#28 ·
I usually get one or two cases of EFB a year. Last year I had 8, this year 7 and counting. It may be that a nearby infected and neglected apiary caused the big breakout last year. This year I think the bees got at equipment bagged for sterilization (rats had chewed holes in the bags, and the sterilization facility only allows small beekeepers a few days in spring) in late winter. I removed the equipment right away but I think the damage was done: I had hoped that 6 months and a few hard freezes would have meant the robbing did no harm, but alas it seems I was wrong. This experience suggests that at least locally we have a pretty durable strain of EFB around.

I have over the years done the medicate-shook swarm-medicate protocol. While it is usually successful, it is not always successful. And the colonies are so set back they take all season to recover. So....since that method requires medication that is now hard to obtain, and was always expensive, and a set of new equipment, and the bees really struggle to rebuild....I now euthanize once I get a positive Vita Life test kit result; it is important to prevent spread.

Euthanasia with a big bottle of rubbing alcohol when all the bees are home and in cluster (night) is quick and as merciful as it gets.

I have not found that EFB just clears up by itself, in a flow, when the bees are fed etc. It just gets worse and worse and spreads. I know some Canadian researchers were looking at samples last year to see if there are different strains. I suspect there are tougher types of EFB around these days.

Countries with low foulbrood rates practice no tolerance for the condition, euthanizing affected colonies and destroying/sterilizing all equipment. That may weed out "poor genetics" but I think we are wrong to place too much blame on the bees. The larger benefit is that euthanasia and equipment burning/sterilization reduces the available pool of foulbrood to be passed around.
 
#29 ·
i appreciate the feedback dar. i suspect the efb originated from nearby imported colonies that became deadout under the care of beginning beekeepers but i have no way to know for sure.


And the colonies are so set back they take all season to recover...

I have not found that EFB just clears up by itself, in a flow...

I know some Canadian researchers were looking at samples last year to see if there are different strains. I suspect there are tougher types of EFB around these days.
i was very surprised to see how quickly the population of strong overwintered colonies became depleted even though were were having an excellent flow and they were building up very nicely coming out of winter. most were not worth trying to save by the time i got my field tests and antibiotics in.

so far:

8 colonies euthanized

3 colonies moved to isolated 'hospital' yard and...

1 colony shook swarmed but absconded prior to being given terramycin

1 colony shook swarmed and given terramycin, already dwindled badly but treated as more of an experiment to check for antibiotic resistance

1 colony is recovering without treatment and the last capped brood frame is showing improvement from less than half the cells reaching capping stage to over 80% capped.


hopefully the u.s. and canada will adopt and make available efb typing which appears to have a lot to do with guiding the course of action in the u.k. as seen in the video linked above.
 
#30 ·
I have not found that EFB just clears up by itself, in a flow, when the bees are fed etc. It just gets worse and worse and spreads
yep... that was my experience as well, old vs new I guess.
My it took me a while to see it, my bees are fairly hygienic so sick larva was being removed, the hives just didn't take off and build up... by the time I knew what was up it seems to have gotten in the cell builder...
My TF roots boned me, all the "old" advice was really appealing... I tried waiting for the flow to get better, then shook swarming, etc. Antibiotic was a line I swore I never would cross,(but like mite treatments, I did) but when I did it was much later than was good for my bees, I lost/put down a lot of hives and I ended up taking huge winter losses.

EFB is a bit of an odd duck, hygienic behavior is ineffective against it, and in fact, Hygienic stocks tend to be EFB susceptible, something to think about in terms of VSH and selecting for mite resistance.
 
#31 ·
yep... that was my experience as well, old vs new I guess.
Hygienic stocks tend to be EFB susceptible, something to think about in terms of VSH and selecting for mite resistance.
Maybe it is EFB that I have had all these years, and not AFB. Sort of dissapointing…

It is just that awfull smell, which is not sour, it is much worse, which has said to me this must be AFB. When trying to make the stick test, it usually is not at all sticky, but of course everything rotting and wet organic material is somewhat sticky. I don’t know. But as I said, the smell is something that I have made up my mind years ago: this is AFB. And that there usually are some sunken, usually more like torn apart and broken, capped larvae cells in the late phase of this disease.

Once I posted one or two honey samples to a field survey and when the results came I remember the advisor told me that there is no AFB in my honey but “EFB is growing so wildly that I´m really surprised if you don´t have some serious problems!” Which I didn´t. He added that sometimes in these situations the EFB bacteria growth overruns the growth of AFB. But again, maybe it was only EFB.

The EFB has become more aggressive if this really is EFB what I have had, one or two hives every year so long I can remember. I have shaken them to clean combs, given food frames from clean hives, that’s all. One of the biggest beekeepers in Finland, Mesimestari (who actually has now sold all his hives and concentrating in packaging honey and selling equipment) had to buy ozone treatment machinery to clean combs. So bad was his situation with EFB.

It is well known that acetic acid kills EFB bacteria, too. Didn´t know anything about ozone.

When lecturing or writing I have very openly told other beekeepers about having foul brood problems in my beekeeping. Often have I gotten that comment that I´m putting too much stress on my bees, foul brood disease and no mite treatments. Many have considered that a combination impossible to win.

Maybe the fact that we have in Finland the worst foul brood situation in whole Europe has been an advantage to me, maybe bees in Finland have some resistance towards these diseases.
As I have told many times, there are several beekeepers saying that my bees have good resistance towards brood disease. Knowing how many years I have had it, I´m not at all surprised if there was some truth in these comments. I even have used some sick hives to build queen cells. Some rot, some survive.
 
#32 ·
I also am coming to the opinion that a lot of the old "expert" wisdom about EFB, either doesn't hold up anymore or or only was valid when a large share of the managed bee population in the US was routinely treated with antibiotics, even in the absence of symptoms, or maybe was never true. I don't know.

Knock on wood, I have so far seemed to have left it behind, this year. But at huge cost to my hive count (I am down to only four colonies), and to my pocketbook after buying multiple sets of brand new equipment, and endless hours of extra work and worry since it first appeared here three years ago. And I did treat, finally.

Although we blame varroa for nearly every problem these days (with good reason) I think the varroa crisis may be obscuring co-existing, perhaps now increasing, problems with EFB. In my yard, I control varroa with intensive monitoring and pro-active - not reactive - treatment. (Though the work of intensive monitoring buys me the chance to treat fewer times per year and still get excellent control.) So, perhaps the EFB issue is more visible.

I think I am going to give acetic acid treatment (for the equipment) a try this summer, since I have been unable to organize a trip to a gamma radiation facility that uses 15KGrays.

If I am truly past the crisis, I will be making increase this year - which I have not done in four years - as I am down to just one colony apiece in two of my four long-running queenlines, having lost one queen line (of my original four) entirely.

EFB sucks!

Nancy
 
#33 ·
At the Missouri spring conference this year, I attended a class regarding EFB.

They recommended a shook swarm onto new frames. Then a few days later doing it again. Said that the bacteria could live in honey stored in the honey stomachs and be transferred to the new frames. The idea was that any honey would be used to start building comb the first time. As soon as the second shook swarm was done, to begin a feeding, I believe with antibiotics. All used equipment should then be burned, including the first set of shook swarm equipment.
 
#34 ·
The really scary part is that the reservoir of disease may not even be in your own apiary! If it is being brought in from surrounding bees, either feral or managed colonies, it puts you on a treadmill.

To do the most assured eradication method of the double shakedown involving destroying two sets of new equipment, would be very costly. If you also had to buy new bees it would be prohibitively expensive for many people. Without assurance that it would even be successful it could surely dampen your enthusiasm.

I am down from 13, to 1 apparently health colony. I have a couple of nucs on order for a trial. This summer will decide whether I am out of beekeeping or not.
 
#35 ·
I think this thread is very timely. I will be keeping an eye out for this scourge. Euthanasia, equipment destruction will be my strategy. Luckily my bees and equipment are not so expensive.

Some of our problems are proper isolation of equipment. I have plans to get a 40 ft container for unused boxes. Be real helpful to have to store contaminated boxes until they could be ionized or properly disposed of.
 
#37 ·
Why do you think those feral bees are so magical:D I hope you are right.

Uncertainty makes a person jump at shadows. I still dont know for certain that I suffocated colonies last winter. Just failed to commence brood up. Something that killed the queens could give similar symptoms. No sign of laying workers but dont know whether that would happen with rapidly decreasing populations. With no larvae to examine a person loses his main evidence to assess EFB

I also have one very weak colony that apparently has no queen to which I donated a frame with healty bees and all stages of eggs etc., to see what they will do with it re starting cells and will check to see if the brood continues healthy or shows slumpy discoloured EFB signs.

If I am really lucky EFB signs wont develop. I will be happy then to know I goofed up and allowed them to suffocate. They appeared healthy going into winter and were strong until late winter: perhaps I did get rid of the EFB last season. If so I will be able to repopulate those hives I have stored away.

I have a couple of Dadant deep frame hives built and an observation hive that I was looking forward to playing with. Such anticipation keeps us going!

Like Nancy said "EFB sucks"!
 
#38 ·
Why do you think those feral bees are so magical I hope you are right.
They aren't magical, but their level of genetic diversity is very high compared to the average commercial queen in the U.S. Genetic diversity gives them a better chance of having genetics to resist diseases.

Hygienic stocks tend to be EFB susceptible
I agree that previous testing seemed to indicate that hygienic bees were EFB susceptible, but it is not proven that there is a linkage between the traits. In other words, it is very likely that bees can be selected for both hygienic behavior and EFB resistance. This would be a very good question to investigate for a breeding program.

We had problems with both AFB and EFB prior to the mass die off of bees in the late 1980's and early 1990's. As the number of colonies in an area decreased, disease problems disappeared. The only case of AFB I saw in that time frame was in 1997 near Gadsden Alabama when a friend asked me to check one of his colonies. It was heavily infected with AFB. We burned it that night. The colony had been purchased from a beekeeper near Albertville and was a recently established colony put into 20 year old equipment. I suspect the equipment had spores that infected the colony.

Two things help with diseases, keeping fewer colonies per yard, and regular comb renewal. Comb renewal in particular is associated with healthier colonies of bees. This is one of the reasons I am renewing quite a few of my Dadant combs this year. The combs being renewed are from 2016 when I moved my bees into square Dadant equipment. I am not having to deal with a disease so the comb renewal is purely for preventive reasons. I expect to renew about 1/4 of the combs in my hives each year going forward. This is fairly easy to do with spring splits by letting each split build a few new combs while culling older combs. Brother Adam wrote that comb renewal is an important factor in disease prevention.
 
#41 ·
They aren't magical, but their level of genetic diversity is very high compared to the average commercial queen in the U.S. Genetic diversity gives them a better chance of having genetics to resist diseases.
A commly held belief that seems not so much in at least the post varroa age, moving bee means moving genetics

“the feral bees in our study region are of recent origin, we found higher genetic diversity in managed than feral honey bee colonies”
“Feral bees had a stronger immune response, even though they were less diverse. However, our findings indicate that the increased genetic diversity of managed A. mellifera may not bear fitness benefits thatcorrelate with immunocompetence. Our results support that management increases genetic diversity in honey bees probably as a result of admixture among progenitor populations as honey bee queens are shipped among regions (Harpur et al. 2012). Domesticated species are generally thought to be less genetically diverse than are their wild relatives (Wang et al. 2014). However, honey bees are unique in that feral bees are derived from domesticated lines in their nonnative range. In addition, honey bees, even when managed, undergo a mix of local breeding, regional dispersal, and natural reproduction among hives from different sources. Yet, what is interesting is that despite this diversity of managed bees, they are less rather than more immunocompetent than the feral populations, suggesting that while diversity matters to immune function, so may the ability of natural selection to increase the frequency of resistant varieties.”

López-Uribe1 Et Al 2017 http://elsakristen.com/docs/LopezUribe_2017_Apis_diversity_immunity.pdf
Diversity is a double edge sword, ferals have had diversity removed as they have been subject to MORE selective pressures… think about it, the whole point of a bond program is a whole bunch of the diversity dies off.


I agree that previous testing seemed to indicate that hygienic bees were EFB susceptible, but it is not proven that there is a linkage between the traits. In other words, it is very likely that bees can be selected for both hygienic behavior and EFB resistance.
Problem is you can’t select for what you don’t have. Hygienic behavior stocks were sussfully selected do to the ability to easily empirically test the trait.
But it has been done.. The early Weaver program was left with EFB/chalk plagued stocks after bonding out a few thousand hives, they had to work very hard to combine efb/mite restiance
it has also failed, Kefuss was able to turn around the EFB issues in his Chile stock, but never got the mite restiance up top TF like he had in France

I think feral bees would quickly develop resistance should a new efb type come through but for a while it would be miserable. I am interested to see how studied feral bees do should an disease outbreak like this hit them.
Well I am not sure they developed genetic resistance to the old EFB to begin with, centuries of “bond” and bees are still sustibult to it
in his book (1853) Quimby notes “Mr. Weeks, in a communication to the N.E. Farmer, says, "Since the potato rot commenced, I have lost one-fourth of my stocks annually, by this disease;"

“Mr. Quimby said foulbrood was not as bad in 1870 as it had been ten years earlier. (This was probably because Italian queens were just being introduced and they are more resistant to European foulbrood)”
https://static1.squarespace.com/sta...story+of+the+empire+state+honey+producers.pdf

About 100 years of “bond” between Quimby recognizing foulbrood and the “invention” of antibiotics… and it still plagues us as it plaged them pre treatment era
 
#39 · (Edited)
Leroy, feral bees in the old days lived so far apart there was little drift between colonies. Any colony with brood disease would simply have struggled and died out. I expect the reason we have a lot of drift between bees in an apiary and between apiaries nearby is that bees never had to develop an ability to go home to a specific 1' window. The only colony for a mile or two was their own! See a colony = getting home....you just needed to be close-ish.

But now we keep them in apiaries, and in my area we are close to banks of pollination bees in the nearby blueberry fields in summer and also in winter if they are guested on local fields as winter yards. Density = drift.

This density drives the sharing of disease and pests. And alas, the pests and diseases can shift their genome far faster than bees do (and are not further challenged by the bees' multiple drone father reproduction strategy, which exerts a very strong pressure against fixing traits). Any kind of resistance you might breed into bees will push the pest/disease genome to a more successful strategy.

Until the foulbrood vaccines (now in research and development) are available, the best defense against pests and disease is to limit their concentration in the bee landscape. This is why countries who practice rigourous euthanasia and equipment destruction/sterilization have low incidences of foulbrood. There ends up being a lot less disease to get around, and the appearance of foulbrood is time-limited, which time limits the opportunity for spread. They also control for mites, which apparently can vector EFB.

I suspect the constant medication of bees to suppress foulbrood also drove the production of ever more resistant and virulent foulbroods. Bee shipping and mobile pollination help move those pathogens around?
 
#42 ·
Now that deserves more information. On a local level, feral bees would tend to stabilize genetics meaning that bringing in managed bees would increase diversity "OF THE FERALS". On a regional or nationwide basis, would you argue that the managed or feral bees have more diversity? Be careful with this one as there is indeed a study showing very low genetic diversity in commercial queens.

This is more telling.

"These findings suggest that genetic diversity is positively associated with immunocompetence in feral honey bee colonies, and that the benefits of genetic diversity are obscured in managed bees, perhaps as a result of artificial selection. We hypothesize that high genetic variability provides the raw material upon which natural selection acts and generates adaptive genotypes in unmanaged populations. Feral populations could be useful sources of genetic variation to use in breeding programs that aim to improve honey bee health."

Seems to me that this counters most of what you attempted to posit.

As for selecting for EFB resistance, that would be fairly easy to do empirically. Set up disease challenge experiments. One way it could be done non-destructively would be to capture a test population from each colony and challenge them with EFB to see which are least affected. Then breed from the colonies that have the best test results.

The study you quoted is testing for "immunocompetence". While it is a valid research result, this was not shown to correlate directly with EFB or AFB resistance. It is kind of like having general disease resistance to bacteria, but maybe still susceptible to viruses or vice versa.

This does not come even close to the common house fly which has resistance genes far more advanced than most other insects. If the honeybee had the resistance genes of the house fly, we might currently be overwhelmed with hordes of honeybees.
 
#43 ·
On a regional or nationwide basis, would you argue that the managed or feral bees have more diversity?
Harper EtAl 2012 Management increases genetic diversity of honey bees via admixture.

"Reduced genetic diversity is a common feature of domesticated animal and plant populations (Brufordet al. 2003) that has been implicated as a cause of col-ony declines in honey bees (Oldroyd 2007; vanEngels-dorp & Meixner 2010). However, we observe an opposite pattern: managed populations have more genetic diversity when compared with their progenitors in E. and W. Europe"
 
#50 ·
a copy of the email i sent to beltsville this am:

"Greetings Dr. Evans,


My name is **** and I am a beekeeper located in northeastern Alabama.

I had a recent outbreak of what appears to be a quite virulent strain of EFB. I first I noticed poor capped brood patterns and discolored young larvae in a few colonies in late March of this year. Not having experienced EFB prior to this I misinterpreted what I was seeing as chilled brood.

After realizing it wasn’t chilled brood I ordered VITA test kits for EFB. There was about a two week delay from ordering to receiving the kits and having the time and weather to do the sampling. Test results were postitive.

From late March to late April, 5 out of 9 colonies in one yard and 5 out of 11 colonies in another yard succumbed and dwindled so badly that I euthanized them. 3 out of 3 colonies at another yard are not affected as of yet. I went ahead and obtained a VFD for terramycin and now have it on hand for possible use going forward.

I have since discovered that there are several new beekeepers within flying distance of the affected yards who have imported bees from out of the area. None of them have successfully overwintered a colony resulting in almost 20 deadouts over the past 3 years. I can’t be sure but I'm guessing this to be the most likely source.

I have been combing the literature and trying to bring myself up to speed with EFB. I have a few questions that I hope you may be able to help with.

1. I see that in the U.K. MLST is being performed on isolates from the VITA test kits to determine the sequence type and to some degree suggesting a course of action for remediation. Is anything like being done here in the U.S.?

2. Does Beltsville test positive EFB samples sent to it for resistance and sensitivity to Terramycin?

3. I was surprised to learn that melissococcus plutonius can survive in honey and on comb for quite a long time and exposure to it can result in new infections. Are you able to confirm that this is happening based on your experience with the samples sent in for processing at the Bee Research Lab?

4. After euthanizing the colonies I brought in the equipment to include quite a few honey supers of drawn comb most of which had not been filled with new honey yet. I have washed this comb with mild pressure from the garden hose, use an air compressor to dry it, and then applied a spray of 3% bleach. Is it possible to have this comb sampled to see if it still holds melissococcus plutonius?

5. I am currently speaking with a gentleman who has an adjunct position at Alabama A & M University in Huntsville. He is involved with their irradiation lab. I am interested in having all of the equipment irradiated, but it doesn’t look like that facility is going to work for this application. Are you aware of any industrial irradiation facilities (other than Sterigenics in New Jersey) that offer sterilization of bee equipment?


Sincere thanks,

****"
 
#99 ·
a copy of the email i sent to beltsville this am...
(see post #50)

the answers received from beltsville today:

"1. I see that in the U.K. MLST is being performed on isolates from the VITA test kits to determine the sequence type and to some degree suggesting a course of action for remediation. Is anything like being done here in the U.S.?

With Dr.Kirk Anderson (copied) we hope there will be an assessment of virulent strains of EFB in he future, to date the recommendations for antibiotic use are consistent regardless of the identified strain and we might assume that symptomatic larvae are the defining trait of virulence, as with strains of the AFB agent.

2. Does Beltsville test positive EFB samples sent to it for resistance and sensitivity to Terramycin?

3. I was surprised to learn that melissococcus plutonius can survive in honey and on comb for quite a long time and exposure to it can result in new infections. Are you able to confirm that this is happening based on your experience with the samples sent in for processing at the Bee Research Lab?

I would say yes to weeks, not years, but this is really for the bulk of bacteria. Naturally, there must be some living or non-living site that maintains M.plutonius when brood are absent (seasonally or in deadouts) but I do not know of any firm tests of viability for more than a few weeks in hive substrates/honey. That will be useful information.

4. After euthanizing the colonies I brought in the equipment to include quite a few honey supers of drawn comb most of which had not been filled with new honey yet. I have washed this comb with mild pressure from the garden hose, use an air compressor to dry it, and then applied a spray of 3% bleach. Is it possible to have this comb sampled to see if it still holds melissococcus plutonius?

yes we can culture from this comb if you send it

5. I am currently speaking with a gentleman who has an adjunct position at Alabama A & M University in Huntsville. He is involved with their irradiation lab. I am interested in having all of the equipment irradiated, but it doesn’t look like that facility is going to work for this application. Are you aware of any industrial irradiation facilities (other than Sterigenics in New Jersey) that offer sterilization of bee equipment?

We have used Sterix (maybe same as in NJ but we used North Carolina) and they are good, but pricey...likely more than hive bodies/frames are worth, unfortunately. Your bleach method can likely have the same efficacy in my opinion

and in another response from beltsville:

Thanks **** and all, yes EFB is definitely resurgent. As for sterilizing equipment, would Dr. **** consider an ethylene oxide chamber? This was used as a norm for treating foulbrood suspect frames in Maryland but is no longer in use. We did a commercial trial with ETO vs. gamma irradiation and fond the former was better at sterilizing. There are permitting issues as it is a biohazard but overall the regulatory and cost hurdles seem less than irradiation.
I just sent a note on your other questions, re the virulence of EFB strains, you might loop in our colleague Dr. Kirk Anderson with USDA-Tucson (kirk.anderson@ars.usda.gov), who is keen on typing strain types with virulence in the hive.
 
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