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3 Weeks ago the hive was booming. Today, there's hardly any bees. The ones in the cells have several that are dead...some have tongues hanging out. I found a hive beetle a couple weeks ago and switched to beetle base board today. There were 3 medium supers almost all full and looked great and normal. I found the queen. She's hasn't been laying very many eggs. When I flipped out the screened bottom board with the beetle board, I saw several culled larvae. The tray under the screen has a beeswax/oil "glue" on it and there are barely any mites and it's pretty clean. This is in SE Nebraska.

I removed 2 of the honey supers, thinking they couldn't take care of so many resources. That leaves them with the brood box and one super.

Any ideas?

I'd add photos, but who can see anything with a max file size of 200K. :/
 

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Could be pesticide poisoning. I would not rely on a bottom board for mite detection. Pull a frame and check some drone brood for mites. The mites prefer drone brood so if there is a lot of mites there then it is likely there are a lot in the hive.
 

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Did you get a chance to look at their wings? I have seen hives fall to deformed wing virus very quickly.
 

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snipsel,

I am in your area. I don’t discount the pesticide explanation, but in my experience, this is the time of year when hives around here can crash very quickly due to mites. The thing same thing happened to me several years ago, and it was a bitter lesson. My two biggest, most productive hives crashed like they fell off a cliff. Believe me, I changed my beekeeping practices after that!

What was your mite count? Had you begun treatments?

The bigger the hive, the harder the crash, since the higher rate of brood rearing can allow them initially to support a higher mite population. Then, when the hive cuts back on rearing brood, like they do this time of year, but the mites continue to reproduce at an exponential rate, the mite load per bee gets to the point where the hive cannot sustain it. Then they crash. Randy Oliver describes this in much clearer terms on his website, scientific beekeeping.

Pupae with their tongues sticking out is one indicator of a crash due to mites. Another thing you can look for is mite guano on the upper side wall of the cells. It looks like sugar crystals only much smaller. The guano is not a sure fire indicator, just a clue.
 

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Mite growth is exponential.

100 mites.
200 mites
400 mites
800 mites
1600 mites (3% - Danger Will Robinson, its time to act)
3200 mites (6% - This hive is in trouble, but if he isn't doing an alcohol wash, the beek doesn't know it)
6400 mites (13% - this hive is sick, very few hives are going to recover from this)
12,800 (25% fatal to the hive)
 

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Mite growth is exponential.

100 mites.
200 mites
400 mites
800 mites
1600 mites (3% - Danger Will Robinson, its time to act)
3200 mites (6% - This hive is in trouble, but if he isn't doing an alcohol wash, the beek doesn't know it)
6400 mites (13% - this hive is sick, very few hives are going to recover from this)
12,800 (25% fatal to the hive)
Sorry to correct you but this is not exponential growth. That is a standard linear growth (2x).
Exponential growth (n x n) is like this:
2
4
16
256
65,535
etc.

Sorry, my mathematics is showing.
 

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Sorry to correct you but this is not exponential growth. That is a standard linear growth (2x).
Exponential growth (n x n) is like this:
2
4
16
256
65,535
etc.

Sorry, my mathematics is showing.
Exponential function is - Y=AB^X.
It is not N*N and not X^N.

So, for a meaningful talk - first define your base (that would be B in Y=AB^X).
For classroom examples, the base of 2 is often used and the coefficient A is often 1 (for convenience).
For mite growth talks, I am not even sure what IS the correct base B and what is correct A.

It is all in Wikipedia, folks.
:)
 

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That would be squared (x)2. Sorry, I'm an Engineer, the nerd is strong in this one...
X^2 - is quadratic function, not exponential function (N^X).

To be more general, X^N is power function (vs. the exponential function - N^X).
So these are some important nerd details.
:)
 

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The list is not linear. Doubling each interval (or generation) is exponential. Don't believe me? Paste it to an excel spreadsheet and plot it. Go ahead and prove it to yourself. That is an exponential curve. The formula there in that list is not 2X, it is 100* 2^X where the exponent X is the number of generations of mites, or Y=AB^X that Greg pointed out.

Your mistake was in not realizing that while the second number is in fact 2x the initial population, the third number is 4 times the initial population, and the fourth number is 8 times the initial population and so on. Linear would be 100, 200, 300, 400.

In actuality, mite populations do more than double per generation, they grow at P*e^rt where P is how many mites you started with. e is Euler's number. t is the number of brood cycles. Since each female produces 3-5 females per brood cycle then setting t to the number of brood cycles simplifies determining r, or if we average at 3.5 mites per generation (accounting for deaths of the mother mites), then about 130%. I didn't intend to get into that, I was trying to answer snispel's question in an easy to understand way by showing how a population of 100 mites that doubles each generation can very quickly overwhelm a hive. I did not intend to get into a mathematics discussion (which I can do, I am an electrical engineer) but please do go back and plot those numbers on an excel graph and tell me if you still think it is linear.
 

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It is not always mites.
It can also be nosema ceranea.
Unfortunately without a microscope you can't confirm it.
When it reaches a critical level in the brood nest/nurse bees the hive crashes quickly.
 

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When the hive HAD many many bees, and no longer does, then for some reason about 6-8 wks ago very few bees were being produced, and now most of those are dead/dying/migrating to another queenright hive.

Typically a hive that had a queen, swarmed, did NOT get a queen back will NOT crash in population like this. There will be "winter bees" left behind, which are bees that emerged from the capped brood after no more larvae needed to be fed. So we can rule out that - unless your hive went queenless 4-5 months ago. They will store honey very well when queenless. We do not have details provided about last sighting of queen/eggs/larvae, so can't rule out a hive that did not get a queen back a long time ago (as in, June).

But.... case study from my apiary... I did alcohol wash on my hives (15) in early June. One had 30 mites/300 bees - 10% of the bees had mites, and likely 20% of the brood had mites. This is bad. I treated all hive 3-4 times in Fall with OAV, no other hives had more than 5/300 (and those had virtually no mite drop on bottom board after treating, so may not have been a true problem in the hive).

So.... I did one OAV, one Formic Pro pad, still had mite counts of 10/300 by July, finally did 2 formic pro pads. Population down to 1/3 of original size - I got 3 supers out of this hive before the crash - by end of July.

They are recovering nicely thanks to support from other hives. At least 6000 mites fell on the bottom board, dead or dying, over the coarse of treating for several months.

So.... what happened? To JUST this hive? Well, either my mite treating over the winter failed, OR they found a hive dying of mites in May and imported more than honey. :(

Then I missed it - and those imported mites got a foothold. That is my theory at this point - if this hive had a crushing mite load over winter, they should not have been super strong in spring and made 3 supers for me before end of June.

That may be what happened here. A mite wash on the current bees may reveal much. A check for mite frass (as previously posted, small white sugar-looking dots on the sides/roof) will also show if the mites reproduced in the hive. Mites that successfully reproduce poop on the sides/roof of the cells; otherwise they poop on the larvae. That's of course harder to see.

If you can't check the mite population in May, then just treat, would be my advice. I find it cheaper to check for mites in May. I'm looking for 0/300, and usually find that. Higher levels than that would prompt me to treat. I like a clean slate.
 

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3 Weeks ago the hive was booming. Today, there's hardly any bees. The ones in the cells have several that are dead...some have tongues hanging out. I found a hive beetle a couple weeks ago and switched to beetle base board today. There were 3 medium supers almost all full and looked great and normal. I found the queen. She's hasn't been laying very many eggs. When I flipped out the screened bottom board with the beetle board, I saw several culled larvae. The tray under the screen has a beeswax/oil "glue" on it and there are barely any mites and it's pretty clean. This is in SE Nebraska.

I removed 2 of the honey supers, thinking they couldn't take care of so many resources. That leaves them with the brood box and one super.

Any ideas?

I'd add photos, but who can see anything with a max file size of 200K. :/
You are describing a typical dead out from mite infestation. Emerging bees with their tongues out. Biggest colony population in the yard. Booming weeks ago, dead today. Queen and handful of bees left (not always, but common).

The hive that has been churning the most brood through the season was also churning the most mites. Those are always the ones to be wary of in the Fall. The hive that swarmed mid-season and is just getting its feet back under it do not usually have bad mite counts this time of year. The more capped brood cells in your hive, the more mites you are breeding.

I strongly encourage you to read grozzie2's link to thread above. I think you will find a very familiar story.
 
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