# Winter Dead-Out Mystery



## 71159 (Jun 26, 2009)

Hello!


I have been keeping bees near the ND/MN border for a number of years now and in that time, I've witnessed some hive losses. Usually, I can pinpoint the problem enough to feel like I understand it (queen failure, mites, starvation, etc). Well, this winter, I went into the season with 4 very strong hives and one reasonably strong hive (1 Italian, 4 Carniolian). I set the hives up for winter in October, installing mouse guards, bee quilts, and candy boards. I left each hive with 2 deep brood boxes and one medium super of honey to winter with. Hives were tilted forward, had exits at top and bottom, and protected from wind. Basically, the same set up I use every winter and I rarely lose a hive. Anyhow, this fall was warm and the bees were active, so my biggest concern was that they’d blow through their honey stores too quickly. I walked past the hives for the first time since November (when all looked fine) the other day when it was nice. All five hives were silent. I couldn't hear the cluster buzz up when I knocked on the hives and saw no indication of life. This afternoon, it's almost 50 degrees out, so I went out to pop the hives open and see what the deal was. All five hives have at least 80# of honey left in them- one deep and the super are completely untouched and the bottom deeps are quite full. Each hive has about 10-15 healthy looking (right color, wings look good, etc) dead bees in it, no queen, no brood (wouldn't expect brood). There weren't any dead bees outside of the hives, no sign of dysentery, no sign of starvation, no mouse invasion- nothing. 


I was wondering if you have any idea as to what could've happened. I'm not sure if the frames are safe to use again or how to avoid a repeat in the future. I'd appreciate any insight you might be able to offer.


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## camero7 (Sep 21, 2009)

put those dead bees in a plastic bag with some alcohol and send them to Beltsville.
http://www.ars.usda.gov/Main/docs.htm?docid=7472


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## Michael Palmer (Dec 29, 2006)

Not even a few cells of brood?


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## beemandan (Dec 5, 2005)

Did you do any mite testing?


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## 71159 (Jun 26, 2009)

Michael Palmer said:


> Not even a few cells of brood?


There are a couple cells of capped pupae in there. It looks like the caps were being chewed off and some had bees that were partway out. My guess is that the bees inside the hive emerged after the rest left and the bees that didn't emerge got too cold before coming out. There are no eggs or larvae (or evidence of them) anywhere.


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## 71159 (Jun 26, 2009)

beemandan said:


> Did you do any mite testing?


Sticky boards periodically through the year. One of the hives was treated in the spring with Hopguard. The others had unremarkable counts all year. They all got grease patties in the fall (for tracheal mite prevention), but they seem untouched and I have no reason to believe there was a tracheal mite problem.


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## Michael Palmer (Dec 29, 2006)

fliese said:


> There are a couple cells of capped pupae in there. It looks like the caps were being chewed off and some had bees that were partway out. My guess is that the bees inside the hive emerged after the rest left and the bees that didn't emerge got too cold before coming out. There are no eggs or larvae (or evidence of them) anywhere.


I figured there would be. And that there would be some that died trying to emerge. and that there would be lots of honey left in the hive, but very few bees...

Once again. The symptoms point to varroa mites. Classic in my opinion.


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## 71159 (Jun 26, 2009)

Michael Palmer said:


> I figured there would be. And that there would be some that died trying to emerge. and that there would be lots of honey left in the hive, but very few bees...
> 
> Once again. The symptoms point to varroa mites. Classic in my opinion.



Even without deformed wings and no mites visible on any part of the bees in there? Where did the rest of the bees go?


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## Michael Palmer (Dec 29, 2006)

DWV isn't the only varroa enhanced virus. It's the bees' instinct to get the sickness away from the colony. The sick bees left one by one until the colony was depleted of bees. Sick bees leaving and no healthy young bees to replace them.


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## 71159 (Jun 26, 2009)

Michael Palmer said:


> DWV isn't the only varroa enhanced virus. It's the bees' instinct to get the sickness away from the colony. The sick bees left one by one until the colony was depleted of bees. Sick bees leaving and no healthy young bees to replace them.


Wow. I never would've guessed. Thank you for your input. Would there still be evidence of the mites in the hives so I could verify? I can't believe that five hives would all fall together with low mite counts on the sticky boards going into winter. Would you suggest treating all hives in the fall, even if they don't seem to need it? I've never had mite problems before and last year was the first that counts got high enough to need any intervention. What a shame.


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## Michael Palmer (Dec 29, 2006)

Pull those partially emerged worker bees with a pocket knife. You may see the DWV there, and/or flat, stunted abdomens. 

What are "low" sticky board mite counts? Have you ever done an alcohol wash? Also, what's in the neighborhood? Fall mite drift can overwhelm a colony of bees...even after they have been treated. What were your results using Hopguard. I don't believe it's a very efficacious treatment.


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## 71159 (Jun 26, 2009)

Michael Palmer said:


> Pull those partially emerged worker bees with a pocket knife. You may see the DWV there, and/or flat, stunted abdomens.
> 
> What are "low" sticky board mite counts? Have you ever done an alcohol wash? Also, what's in the neighborhood? Fall mite drift can overwhelm a colony of bees...even after they have been treated. What were your results using Hopguard. I don't believe it's a very efficacious treatment.



I pulled a couple bees out and they look totally normal, so no DWV or the like. That said, I was reading a bit online about symptoms of mite death in a hive and saw mention that the mites will leave a white substance on the top of the cell. I do see areas in the brood chamber where the empty cells have a small white splotch on the upper inside surface.

Low counts for mites are <20 mites in the board after 4-5 days. At least that's what I've always looked for. The Hopguard seemed effective when I used it. There was a massive drop off of mites during the treatment and then when I put the sticky board in after treatment was over, there were 3 mites after a week. 

I live out in farming country now, so the hives have woods on one side, a slough on one side and fields on the remaining sides. This year, those fields were soybeans. If you go out their foraging distance, you'd hit maybe 6 houses and the rest is cropland.

Again, than you so much for all of your help. I really appreciate you taking the time to figure this out for me


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## Richard Cryberg (May 24, 2013)

fliese said:


> Sticky boards periodically through the year. One of the hives was treated in the spring with Hopguard. The others had unremarkable counts all year. They all got grease patties in the fall (for tracheal mite prevention), but they seem untouched and I have no reason to believe there was a tracheal mite problem.


I really do not want to start a public pissing contest over sticky board testing versus other methods. My opinion based on experience and a lot of reading, including Randy Oliver's site, is there is only one reliable mite counting method. The alcohol wash. All other methods are loaded with problems and sticky boards are just about the most unreliable.

You treated one hive with Hopguard and the others were not treated at all. Hopguard may work sometimes if the temp is perfect. It never is going to work really well. By far the easiest treatment is apivar. Where it still works its effectiveness is very high. Around 99% kill. Nothing else we have comes close to that. But, there are pockets of resistance showing up so its days are probably really numbered. I put apivar on every hive late March or no later than April 1 automatically.

For a fast kill MAQS is effective providing temps are right. It will generally shut down the queen for a week and will kill some brood and perhaps bees. It will kill the occasional queen.

Oxalic is now legal either as the dribble or vapor. Both are highly effective but the dribble seems a bit harder on the bees, but not near as bad as MAQS. If brood is present neither will kill mites in the brood. So, both need to be repeated every week for three weeks.

By the time you see things like DWV symptoms your hive is likely dead but it just does not know it yet unless it is early in the year. Hives showing virus often take two months or more to clear out the virus after the varroa are killed. Where you live you need to be pretty mite free (down to one mite per 100 bees or less) by about Aug 1 to allow time to raise healthy winter bees. I go into winter with lower than 2 mites per 100 bees in early Sept in a worst case and still have an occasional hive die. Lost one out of 17 this winter.

I am surrounded by people who do not control mites. They have winter losses of 50% to 90+%. None ever have the low losses I have. Some do make a half hearted attempt. Such as blindly throwing on a MAQS strip Sept with no mite counts ever and no other treatment ever. Sept is simply too late to raise healthy winter bees. Does your doctor tell you to take an antibiotic simply because it is January and lots of diseases go around in Jan? I hope not. I would hope he told you to get a flu shot months before that and a pneumonia shot if you have not had the current immunization months before that.

Dick


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## 71159 (Jun 26, 2009)

Good to know. Up until this point, I've lost one hive to starvation, one to it being too cold to break cluster and move (so basically starvation) and one to a failing queen late in the year (I let it die out instead of trying to save it). Maybe I've gotten lucky. I don't pretend to know what the best practices are. I really try to avoid harsh treatments or treating for things that aren't a problem though. I don't like the idea of treating for mites if the counts are low because it'll only add to the resistance problem (much like I don't worm my sheep unless they have a parasite load that warrants it). Anyways, it sounds like I should switch to alcohol shakes and just accept that I'll be sacrificing some of the population, which is ultimately better than losing the entire hive. Like I said, last year was the first year that I had any indication that I had mite issues, so it was the first time I ever had to treat, and turns out the first year I've had a massive loss like this. They've generally wintered beautifully for me without anything other than the IPM practices that many books talk about (such as sticky boards). Live and learn, I guess. I just wish I could've learned this lesson on one hive instead of five.


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## aunt betty (May 4, 2015)

Beltsville, Maryland has the answers you seek. 
Send them some samples and they'll email you the results.
http://www.ars.usda.gov/main/site_main.htm?modecode=80-42-05-40


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