# Do Mites Cause Absconding?



## AHudd (Mar 5, 2015)

Grozzie2 posted an informative thread called "Anatomy of a Mite Crash;" https://www.beesource.com/forums/showthread.php?347723-Anatomy-of-a-mite-crash&p=1656069#post1656069

He specifically asked that no questions be asked so as not to have the thread spiral into an us versus them slug fest on treating. So, I am asking the Question here.

I had come to the conclusion that bees will abscond due to mite pressure in a last ditch attempt at survival. When the population dwindles down to the point that there are not enough bees to care for the brood and not enough bees to clean out cells so the Queen can lay eggs in a tight pattern. It is much less efficient to keep brood warm when it is scattered about. I thought this was the tipping point when the decision to abscond is made. When the collective comes to the conclusion that we can't survive under these conditions, there is not much they can do other than leave.

I thought this is why hives are found with honey and no bees. They have taken all of the stores they can to start a new life somewhere else, whether that be to try to start a new colony or beg their way into another. That may be why some people report finding a Queen and no bees.

I could very well be wrong. I would like to know.

Thanks,
Alex


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## Mike Gillmore (Feb 25, 2006)

Grozzie touched on that in his thread.



> An autopsy of the colony will show virtually no bees left, brood frames with a fair amount of spotty capped brood, now dead, probably a few with heads sticking out as they tried to emerge but didn't succeed. For those who have never seen it happen before, these symptoms must add up to 'they absconded' because it doesn't seem realistic for that many bees to die off so quickly. Reality is, they died, and that many bees did die off that quickly.


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## crofter (May 5, 2011)

I thought it was the straight mathematical abruptness of exponential decline. Virtually no brood rearing for replacement and the whole cohort of aged out foragers flying off to die (which is the pattern where possible, rather than dieing in the hive. 

Just my feeling, but I think it is nothing as romantic as hopelessly striking out in a concerted effort of _last ditch survivalism_.


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## AHudd (Mar 5, 2015)

Yes, I agree the decline is rapid. But, I keep reading where people say they had bees yesterday, today there are none or all they find is the queen. One recent poster claimed he had a lot of bees in a hive and he witnessed their departure. I asked if there were any bees left and he said none. 

I don't have any first hand experience with absconding. I did witness the rapid decline of a colony but I shook it out before it got that far gone and started treating the others.

I'm not doubting anyone, I'm just confused and trying to reconcile all the things I read. You know, things like it had lots of bees yesterday, they were coming and going like crazy and today none. They are not deliberately lying, maybe they just don't know the difference between normal activity and a robbing frenzy. Or they don't want to report that they haven't been in their hives for a month or more. IDK

I want to take everyone at their word. I don't have much experience dealing with varroa and all of the attending complications. It would make it a lot easier for people with my level of understanding to learn if people with my level of understanding would report factually what is occurring without trying to conceal our inexperience or lack of diligence. I think everyone understands that life sometimes gets in the way of our plans. It is also easier for people to help us if we report the facts accurately. But then, we have to weed out the BS from the rest without offending anyone.

Alex


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## grozzie2 (Jun 3, 2011)

AHudd said:


> He specifically asked that no questions be asked so as not to have the thread spiral into an us versus them slug fest on treating. So, I am asking the Question here.
> 
> I had come to the conclusion that bees will abscond due to mite pressure in a last ditch attempt at survival. When the population dwindles down to the point that there are not enough bees to care for the brood and not enough bees to clean out cells so the Queen can lay eggs in a tight pattern. It is much less efficient to keep brood warm when it is scattered about. I thought this was the tipping point when the decision to abscond is made. When the collective comes to the conclusion that we can't survive under these conditions, there is not much they can do other than leave.
> 
> I thought this is why hives are found with honey and no bees. They have taken all of the stores they can to start a new life somewhere else, whether that be to try to start a new colony or beg their way into another. That may be why some people report finding a Queen and no bees.


I didn't ask for 'no questions', I asked for 'dont ask about treatments', specifically to try keep the thread on track about the reasons a mite crash runs quickly, and how it can look like an abscond to those who have never seen it before.

The original post was long, but I did try to emphasize the important point around the 'perfect storm' of bee deaths happening during the crash.

A colony has 3 generations of bees during normal healthy colony development. a) The foragers, aged 3 to 6 weeks. b) House bees aged 0 to 3 weeks. c) The brood in development. In a healthy colony the forager generation is dieing off from the cycle of 'worked themselves to death', to be replaced with house bees that graduate to foraging, and emerging bees taking over the house bee duties. The system is stable.

The perfect storm of deaths culminates with all 3 generations dieing off simultaneously. Foragers die off on the natural aging cycle from working themselves to death. The house bees are dying off due to virus loads that impair the ability to do normal house bee tasks, so they crawl/fly away when they can not properly perform foraging duties. The emerging generation is highly compromised with even higher virus loads and deformations which prevent them from doing normal young bee tasks, so they crawl out and away to die, if they even get fully emerged before dieing.

At the beginning of this phase, from the outside, it appears to be a thriving colony, but it has just reached the point of no return. Foragers start to die off, and at the same time, older house bees are dieing as they should be graduating to foraging. Those that can fly, should be starting to forage, but more and more are being pressed into undertaker duties instead of foraging, which results it a rather abrupt slowdown of incoming resources. That causes the queen to slow / stop laying. A week into this phase you have a colony that is starting to dwindle very noticeably, and there is really no recovery possible anymore. Eggs are not being laid at a rate that can keep the population sustainable moving forward, and the house bee population isn't healthy enough to feed a generation of larvae properly even if the eggs end up in cells. Colony still has a fair amount of capped brood, but, soon doesn't have enough bees to properly incubate that brood, so the brood starts dieing in cells from chilling overnight.

One of the reasons behind the abrupt crash is the preference for drone cells by the varroa mite. As long as the colony is raising drones, mites will prefer to compromise the drone cells, so you will still be getting a relatively healthy worker population on each successive brood round. But there comes a point in the season where the bees stop raising drones, and at the same time are reducing the number of worker cells in progress. That is the tipping point, because now you have a larger mite population and no drone cells for them to try enter, so they end up in worker cells The colony goes from a small percentage of worker cells compromised by mites to suddenly having virtually all worker cells compromised. When you reach that point, where the majority of worker brood is mite compromised, that is the point of no return and the setup for the crash. The final coup de grace doesn't come for another brood cycle, but it's unpreventable once the mite population exceeds the brood population. ofc, this process accelerates dramatically if the mite population gets large enough to exceed the drone cell population before the colony stops raising drones.

I think this to emphasizes another point folks possibly overlook, the focus is always on mites as a percentage of bee population. That's not the ratio that matters, what matters is mites as a percentage of the capped brood population. Again follow some numbers. Healthy colony running 1500 eggs a day has a population of 60,000 (round numbers). Lets just postulate you measure a 2.5% mite load, so, estimate that at roughly 1500 mites in the colony, and roughly 30,000 brood in progress, of which 16500 will be capped workers (ignoreing drones which are likely not being produced anymore). But the queen slows down, and 2 weeks later you are down to 750 eggs a day, so that will result in only 8000 capped brood. In that same period, the 1500 mites becomes on the order of 3000 mites. Soon egg rate is down to 500 a day which will result in 5500 capped brood, and a mite population of over half that amount of brood. The mite growth cycle is NOT in sync with the bees, it's over a 2 week period while the bee cycle is 3 weeks. A couple more weeks into the progression, now you have more mites than brood, and only now is the original healthy forager population starting to expire from age. The perfect storm is in progress and far past the point of no return, but all along the population 'looks good' because it's been an almost full size forager population creating lots of entrance activity. Over the next couple of weeks the majority of the original forager population expires naturally, entrance activity grinds to a halt so the beekeeper opens the hive to look inside. What they find is a very small patch of capped brood, very few bees, and a colony on it's last gasp. If that check is delayed another week or so, you find a virtually empty hive, even tho it looked 'perfectly normal' at the entrance only 2 or 3 weeks prior. What you didn't see at the entrance was the process of 3 successive generations dieing off simultaneously. It's not unusual to find a colony in this state with a full stack of winter stores tucked away, ie lots of honey etc. OTOH, if there are other colonies in the area, it may well be robbed clean by the time you look inside.

In this scenario, what should have been the longer lived winter bees being raised late in the season actually became a generation of virus loaded house bees that could not sustain a healthy colony.

The reason this starts to look like an abscond to folks who were not aware of the pending mite problem is inherent in the genetics of the honeybee as a social insect. Unproductive bees will fly or crawl away from the colony for the good of the colony, they are altruistic. Another inherent trait, honeybees clean house, so any population left alive inside the hive will clean up, ie they will grab onto a dead bee and carry it away from the hive. The combination of these to instincts leaves the hive looking like 'all the bees left', and in reality they did leave, but they didn't leave to start a new colony elsewhere.


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## AHudd (Mar 5, 2015)

Sorry, you did say you didn't want questions about treatments. My mistake.

Thanks for the extra explanations. The point about % of mites to capped brood as opposed to merely % of mites to bees is something I hadn't thought about much.

When people say they were here yesterday, but all gone today, as in zero bees, is that an absconding caused by something other than mites? What could cause this in a two or three year old colony?

What I am very confused about is the point in time a hive becomes empty. Even exponential death of a population of 1000 bees doesn't happen within a 24 hour period, or does it? The answer to this question would clear up a lot of my confusion.

Thanks for taking the time to write the anatomy of a mite crash and for commenting here.

Alex


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## grozzie2 (Jun 3, 2011)

AHudd said:


> Even exponential death of a population of 1000 bees doesn't happen within a 24 hour period, or does it?


In a normal healthy colony, queen lays 1500 eggs a day, population is stable, that means bee are dying off at a rate of 1500 a day.

Now look at the crash scenario. The forager generation was produced in a more or less healthy state, so dieing off at 1500 a day 42 days after they emerge. The house bee population was produced with a slowing queen, somewhere between 500 and 1000 a day, call it 750. They are dieing off prematurely at that rate, so that's another 750 dieing at an age of about 21 days. The emerging bees are dieing quickly, they were produced with the queen laying 300 to 500 a day. Tally it up. 1500 + 750 + 300 = 2550. 2550 bees in warm weather will cover 2 frames, so, yes, look today and see 2 frames of bees at the tail end of the mite crash scenario, now look tomorrow, not a live bee left. You can easily have 2500 a day dieing off, and with no brood emerging, the population goes from big to nothing at a fairly rapid pace. You can have 15 to 20 thousand bees die off in a week in this scenario, so that a drop from what looks like 6 fully covered frames, to nothing, in a week.

I think there is another part folks tend to miss, populations look stable in a full size colony, folks overlook the fact it is a stable number, but, there is a high turnover of bees constantly. I point this out when re-assembling a hive with a newbie, and they are working to hard to try not squish a single bee when restacking boxes. In a healthy colony, 1500 bees are dieing off every day, so if we accidentally kill half a dozen during inspection, it's not a negligible effect on overall population. The exception would be during fall population contraction, when the colony is raising the longer lived winter bees. Personally, we dont inspect colonies anymore at that phase of the season, just weigh them and put on feed as necessary. It's far to late to try 'fix' anything anyways, either they are healthy and ready for winter, or they are dead and just dont realize it yet. There is no in between in the latter part of the season.


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## Eikel (Mar 12, 2014)

Have you read or heard Dr Samuel Ramsey's presentation on mites? It's off the OP of absconding but does provide a potential exacerbating factor in a rapid decline. His research is showing the mites are not truly phoretic (aka a benign passenger), we already knew that but he's scientifically proving the how and what the mites are parasiting. 

Specifically, the mites are feasting on the fat (vitellogenin) rather than the blood (haemolymph). Getting rid of the fat doesn't sound like a big deal, except for the bees it's more of an organ than just some cells laying around. Per Randy Oliver's definition, "Vitellogenin is used by other animals as an egg yolk protein precursor, but bees have made it much more important in their physiology and behavior, using it additionally as a food storage reservoir in their bodies, to synthesize royal jelly, as an immune system component, as a “fountain of youth” to prolong queen and forager lifespan, as well as functioning as a hormone that affects future foraging behavior!" 

The point being a heavy mite load depleting the vitellogenin undermines the whole population stability, the loss is virtually invisible to the beekeeper and enables a slight decline to become a landslide very quickly.

And just to complete my spin off into the deep end, the mites use external digestion where they secrete "juices" into the bees abdomen and suck out the good stuff. Once the mite has significantly robbed (but not killed) the bee, it will climb from the abdomen and find another host, i.e. a mite riding on a bee (frequently shown in pictures) has either just arrived on the bee or is leaving a sinking ship.


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## AHudd (Mar 5, 2015)

Thanks Grozzie for the further explanation.

Eikel,, I had heard about the Vitellogenin when it was suspected but nothing since then.Thanks, I'll start looking for that now. 

It seems I'm always behind on this.

Thanks again,
Alex


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## GeorgeManning (Nov 3, 2015)

Mike Gillmore said:


> Grozzie touched on that in his thread.


Could be a result of wasp pressure. If, during these last few weeks, wasps and bees are in and out of the hive and then you open that hive to see both wasps and bees robbing, and if you see emptied honey cells, you may have robbing that is caused by wasps that caused hive to abscond and soon after see bees robbing along with wasps. Look at the bottom board. It will tell you the rest of the story.


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## Oldtimer (Jul 4, 2010)

Over here our bees are descended almost entirely from Italians and Carniolans, with a very small amount of old British AMM genetics.

I get to see a lot of hives in various forms of distress because I have a part time job as a government inspector. As I see it, the majority of hives that die of mites here do not abscond, they just dwindle and the queen is normally among the last to die.

Absconding happens in a small percentage of these hives, when it does the swarm would typically be fist sized or smaller, and no bees or just a few straglers will be left in the original hive. I have used the odd queen from these swarms, but without human help the odds of any of these absconsion swarms surviving is near zero. Too small, and wrong time of year. 

Absconding is a very common survival startegy in some African bees, and they will do it for a variety of reasons, even sometimes, just from a beekeeper roughly handling the hive. I assume that when our NZ bees do it, it must be from some deeply embedded genetic code from way back. As has been said, it only happens when survival in the parent hive has become impossible, so it's a final attempt to survive, like a drowning man clutching a straw. But the great majority of hives do not do it at all.


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## elmer_fud (Apr 21, 2018)

this thread was started 2 years ago and then revivied


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## Jack Grimshaw (Feb 10, 2001)

Grozzie2
Thanks for posting a fantastic explanation.In my TF days,I saw this too often,especially after the spread of VDV-1. I have tried to explain this to a few beekeepers but it's like whack-a-mole.Every fall a new group brings up a "fall swarm that they missed" or " the bees absconded".
A few points I would like to add.
With the rapid decline in bee numbers,very often the queen is one of the last bees left.
The less experienced beekeeper sees steady bee traffic at the entrance and assumes all is well when in actuality,the declining colony has reduced defenses and robber bees go unchallenged.
Towards the end,the viruses become so prevalent that the larger larvae become infected and there is a change in appearance.They become less glossy,with a dull,almost yellowish colorization, very similar to EFB but with no twist.

Would you mind if I posted this in some other groups,most likely as a link to the original post.You can give us your real name or remain as grozzie2 from Canada.

Thanks again.


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## Fivej (Apr 4, 2016)

I am glad this thread was revived. It is an interesting discussion and not "time sensitive" Besides, not much discussion on the forums lately. 
I do not have an opinion as I do not have enough real life experience. I find myself being swayed by both points of view. I think it is logical that both scenarios are possible. I do think an abscond is not out of the question. There are several experienced members here who have said that absconds rarely happen and beekeepers too often use it as if it was common as an excuse for an underlying problem. The underlying problem these days is mites or mite related. J


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## username00101 (Apr 17, 2019)

I have never seen absconding, but I know beekeepers where it has happened.

The common theme are inadequate mite treatments.


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## msl (Sep 6, 2016)

I have seen it once... the nuc was started with a cell and given a broodless dribble in mid Aug.... and then got crushed by mite bombs.. When I saw it I knew what was up I went and grabbed the camera to shoot a quick video off the cuff as usual enjoy watching me fumble in the wind

a have had a few mini mating nucs abscond when it gets hot.. you come back and its empty except for some bees emerging and stumbling around wondering were ever one is, and this is what a "real" abscond looks like, they all go leaving the brood behind but this was the only time I have seen a full nuc or bigger abscond... and in realty they weren't a full nuc any more as the PMS cut them down to mini mating size.. if that..




__ https://www.facebook.com/video.php?v=1032865103891726


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## AHudd (Mar 5, 2015)

I just noticed today that this had been revived. 
The one thing I have noticed about my bees is that twice yearly treatments with OAV was no longer getting it done. My schedule is now 3 treatments 5/6 days apart after honey supers come off. I try to catch their brood-less period in the heat of Summer for a treatment before they start to raise Winter bees. Also, another treatment during the Winter brood-less period.
The only mite monitoring I do is through the Drone Brood in undesirable colonies. I built some bottom boards with an extra quarter inch between the bottom board and the brood box. They use this space to build Drone comb in the Spring. I scrape the comb off and flatten it with my hive tool. I leave it in the desirable colonies. I do the same with any comb between the brood boxes.
I bought some Drone frames last year that I will be using this year for raising Drones from my better colonies and for mite monitoring. 

Alex


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## Gray Goose (Sep 4, 2018)

AHudd said:


> Sorry, you did say you didn't want questions about treatments. My mistake.
> 
> Thanks for the extra explanations. The point about % of mites to capped brood as opposed to merely % of mites to bees is something I hadn't thought about much.
> 
> ...


Alex

IMO folks seeing "bee " traffic think the hive is ok.
some of these folks do not know the robbing traffic VRS the foraging traffic.
Some wish to hide the fact that they do not know or should have inspected sooner.
And there could be an abscond swarm, more data needs be collected. But earlier you said you try to take people for what they say. I try to understand what they "thought they saw" Words like "bee traffic" are simple English words but have different meanings to different people. 

IMO the collapse is across all 3 generations and can seem like an abscond, but likely is not. The loss would accelerate as more of the bees get sick and leave, and fewer are replaced, the last few could be in the hive or not depending on flying conditions.

GG


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