# Blueberries and EFB



## wildbranch2007 (Dec 3, 2008)

http://www.loudounbee.org/reports/EFB.htm

Severe outbreaks of EFB often occur after bees have been to blueberry plantations for pollination

http://www.extension.org/pages/2369...isease-affecting-honey-bee-brood#.VE4zF_ZASM8

European foulbrood occurs on all continents where honey bees are kept (Shimanuki 1997). During the early 1980's in the U.S., it was historically severely problematic in New Jersey during the spring cranberry and blueberry pollination season. This created some suspicion that low nutrition in pollination fields were having an effect on EFB occurrence, but this did not seem apparent in trials conducted by the USDA (Herbert and Shimanuki 1984). This regional outbreak in New Jersey pollination fields was not consistent. Herbert et al. (1987) reported that in 1986-87, European foulbrood could not be found in the New Jersey, USDA test colonies, while previous to 1986 the disease was a serious problem.


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## drlonzo (Apr 15, 2014)

It would seem that according to the literature the problem may not be at all with the area/crop being pollinated, but instead the fact that someone brought some hives with EFB into the area and the bees from those hives have ended up in yours by drifting etc. This would in fact spread the bacteria as the bees have it within them. However, it would seem like there would be a need for many bees that were in fact laden with EFB spores to enter a hive with good population to do harm. 

But then again, If it were noticed after the pollination of a certain crop, it would also seem that there is something around there that is laden with the spores that the bees were getting into and bringing back to the hive. 

To figure it out for certain a person could place a few hives to test with after the pollination had ended and all bees were gone. If the hives ended up with EFB then it could be said that it was something environmental causing the outbreaks, however if it were the opposite and the bees didn't get EFB then the problem would more likely remain as a problem with someone bringing bad hives in for pollination.

Just my take on the situation.


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## sqkcrk (Dec 10, 2005)

Thanks Thomas. That is my question. No way can I leave any hives behind. I take them out so the grower can do some spraying that would be lethal to any bees left behind. There are no other hives in the area. This blueberry farm is quite isolated and distant from other blueberry farms and other bee hives. But what you wrote makes sense.


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## drlonzo (Apr 15, 2014)

Mark, How many of your hives ended up with EFB after pollination?


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## sqkcrk (Dec 10, 2005)

Yeah, that's a good question. Out of the 240 in blueberries, I'd estimate maybe 24(?). I'm not sure. And it cleared up over time.

What brought this question to a Thread on beesource was a question I got asking about the "relationship between AFB and EFB". I'm not aware that there is one. It isn't like one follows another. I have never seen them both in a hive at the same time either.


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## drlonzo (Apr 15, 2014)

Interesting. I just read another article about a study done in the UK on EFB. It seems that there is actually a reinfection rate in colonies that have been treated for EFB. Here's the link http://www.extension.org/pages/23697/shook-swarm-and-otc-antibiotics-for-european-foulbrood-control#.VE5Gg2d0w5s 

So you had about 10% infected during pollination. Since I'm not in the pollination game at the moment, please give me a crash course, how long were they there, and what was the previous crop and time there? 

I haven't ever heard anyone of any knowledge say there was a relationship between them.. They are both caused by bacterial spores, but both are a different spore. I'm not sure they could both be in a hive at the same time really. Considering one kills the brood before being capped, and the other after the capping.


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## sqkcrk (Dec 10, 2005)

Hives were moved from NY to SC in November 2013. In March 2014 hives were moved from SC to NC around March 18 and stayed on site for about 6 weeks. So the previous crop was the previous Summer's locations where honey is produced, where they had been from late May until late November.


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## drlonzo (Apr 15, 2014)

Well that does narrow the ability of getting into anything in the previous location. In your original post you mentioned last spring, are you speaking of the spring of 13, or 14? 

If it were the spring of 13 then, what is in the article I posted the link for sort of makes sense about the reinfection of the colonies. Do you recall how many you had come down with EFB then? 

If it were just this year, then only a finger could be pointed at the location they were in as the fault for sure.


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## odfrank (May 13, 2002)

I had three EFB colonies all last year, they went through the winter, recovered late and produced a late box of honey. They were treated with Mann Lake patties, which for a long time made no improvement. Several others died and were melted down. One box in the melt pile caught a huge swarm and is thriving. Here is the video of it coming in: 

https://www.youtube.com/watch?v=PvR0ybmcs1A&list=UUdeOrgFk3sLorf8olIvQeog


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## JSL (Sep 22, 2007)

Mark,

EFB today is not what it was say 20 years ago. There appear to be more virulent strains out there and can travel on or in the bees themselves. There are instances of EFB infections on new equipment started with packages. EFB still appears to be stress induced, but once it gets started it can devastate the colony.


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## sqkcrk (Dec 10, 2005)

drlonzo said:


> Well that does narrow the ability of getting into anything in the previous location. In your original post you mentioned last spring, are you speaking of the spring of 13, or 14?
> 
> If it were the spring of 13 then, what is in the article I posted the link for sort of makes sense about the reinfection of the colonies. Do you recall how many you had come down with EFB then?
> 
> If it were just this year, then only a finger could be pointed at the location they were in as the fault for sure.


By "last Spring" I meant the Spring of 2014. I don't recall any EFB at this location the two previous years I had bees there or the previous years anywhere.


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## drlonzo (Apr 15, 2014)

With that information it makes my mind swirl a bit. Is there a possibility of contaminated equipment? Possibly from an outside source?

Of course you would have had to put it into use last year, to have it cause problems this year.. 

I know you're commercial, did or have you possibly hauled someone else's bees for them during the time you took yours to the blueberries? With netting over the hives, the bees could easily enough move between them and cause an EFB problem if those hives had it. 

Just the thought that there would be enough bees from other hives while in the fields that migrated to your hives having EFB to cause an outbreak seems not likely. I would tend to think that they would have to have gotten into something like old hives with EFB in them around that area to get enough spores to cause outbreak. Something strange for sure..


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## beeware10 (Jul 25, 2010)

mark
way back in the 70's and 80's it was a problem for norm sharp. I don't believe they pick it up from other bees. back then norm blamed it on stress and poor pollen. paul cappy was his hired man back then. maybe he would be a good person to ask.


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## sqkcrk (Dec 10, 2005)

drlonzo said:


> I know you're commercial, did or have you possibly hauled someone else's bees for them during the time you took yours to the blueberries? With netting over the hives, the bees could easily enough move between them and cause an EFB problem if those hives had it.


Nope, never haul anyone else's bees.


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## azbees (Jul 23, 2011)

Mark
how many hives did u have on how many acres? 
I pollinated some alfalfa seed and had some EFB and blame it on stress of bees due to lack of forage and probably had weaker queen's.


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## Haraga (Sep 12, 2011)

That's odd that alfalfa in bloom was poor forage. Is there anyway that we could link this to neonics?


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## sqkcrk (Dec 10, 2005)

azbees said:


> Mark
> how many hives did u have on how many acres?
> I pollinated some alfalfa seed and had some EFB and blame it on stress of bees due to lack of forage and probably had weaker queen's.


240 hives on about 140 acres of blueberries and they gained weight.


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## BMAC (Jun 23, 2009)

drlonzo said:


> I know you're commercial, did or have you possibly hauled someone else's bees for them during the time you took yours to the blueberries? With netting over the hives, the bees could easily enough move between them and cause an EFB problem if those hives had it.


interesting thought on community netting. Certainly sharing loads is a concern but i think more of a concern at holding yards rather than on the truck. However contaminated nets probably cant be ruled out, especially for afb. I would be more concerned about contaminated wax and honey getting on the nets, but mashed up bees in nets can be issues too.


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## wildbranch2007 (Dec 3, 2008)

sqkcrk said:


> Hives were moved from NY to SC in November 2013. In March 2014 hives were moved from SC to NC around March 18 and stayed on site for about 6 weeks. So the previous crop was the previous Summer's locations where honey is produced, where they had been from late May until late November.


did the guys that drop hives around you in SC, that didn't go to NC also have the same problem?
You were going to treat with APIVAR in the spring, were you treating while in blueberries?
how was the honey/pollen flow in SC b/4 you went to NC?


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## Michael Palmer (Dec 29, 2006)

JSL said:


> Mark,
> 
> EFB today is not what it was say 20 years ago. There appear to be more virulent strains out there and can travel on or in the bees themselves. There are instances of EFB infections on new equipment started with packages. EFB still appears to be stress induced, but once it gets started it can devastate the colony.



Joe, I was taught years ago that the EFB problem with bees on blueberries was because an acidic environment was created within the colony. Any truth to that?


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## JSL (Sep 22, 2007)

Mike,

I can't comment on the acidity as I am uncertain of that one. The early research suggests it is more of a timing and nutrition issue. Bacteria are present in the hive and the surrounding environment. When both bacteria and developing bees are being fed adequately, there are little or no visible symptoms. When that balance is broken, such as poor protein coming in or a sudden change in foraging patterns such as a sudden nectar flow, things change. More bees become foragers, putting a strain on feeding duties. Then there just seems to be EFB hot spots.

Older EFB studies suggest the disease would clear itself as the season progressed. Today's EFB seems to persist longer and be more devastating. Perhaps our bees are more stressed today.

I think the most challenging part of EFB is the low level/background infections, present in operations, especially queen rearing operations. The signs are subtle, but hard on queen cells too.


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## Ben Little (Apr 9, 2012)

Interesting stuff, I only had 122 rented to blueberry growers this year but I saw no signs of EFB in any hives. 
I wonder if it was someones bees that drifted into the hives that caused the EFB ?

I will definitely keep an eye on this issue if there is in fact an issue with bees contracting/developing EFB somehow from Blueberries because it is my main pollination crop.


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