Every last mite ?
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  1. #1
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    Default Every last mite ?

    Until this year I've been dosing with VOA once a year during one of the warm days we often get here in mid-winter - which has proved enough to keep the Varroa problem in check - but had been planning to engage in a program of multiple-dosing during the season from now on ...
    But as someone pointed out when I mentioned my use of anti-robbing screens and wider spacing between hives to help stop intra-apiary infestation - none of these measures will stop the bees from bringing back into the apiary mites they pick up from outside of it.

    This has caused me to challenge (in the academic sense) the rationale behind attempting to eliminate every last mite from a colony with 4 doses every 5 days, because of this subsequent mite importation from outside.

    I was particularly impressed by a talk given by Marion Ellis about the Varroa mite [https://www.youtube.com/watch?v=q4WvPNmS7uc] in which he graphically demonstrated the consequences of treating mites at various times of the year - i.e. the mite populations which later resulted - the object of doing so being NOT to eliminate every last mite, but to decimate the mite population sufficiently such that it never has enough time in which to recover the numbers required to cause a colony collapse.

    I'm now wondering whether such a strategy of 'acceptance' might be preferable to the pursuit of a complete (albeit temporary) elimination - with a single dose (say) being given monthly, or bi-monthly throughout the season - that is, for those with really large numbers of colonies.
    LJ
    A Heretics Guide to Beekeeping http://heretics-guide.atwebpages.com/

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  3. #2
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    Default Re: Every last mite ?

    I remember someone posted that he was doing once a month single treatments during flying season. He didn’t say if he was monitoring the mite populations tho.
    Rod

  4. #3
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    Default Re: Every last mite ?

    I believe you are on the right path. Eliminating every mite is close to impossible. Knock them down to the point where they stop causing major issues and move on. There is a point of diminishing returns with treatments. A full treatment to kill 1,000 mites is worth the time taken. A full treatment to kill 1 mite, probably not worth the time and money. Would you really want to spend $15.00 on a MAQS treatment to kill only one mite? Marion Ellis has the right idea.

  5. #4
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    Default Re: Every last mite ?

    Quote Originally Posted by little_john View Post
    This has caused me to challenge (in the academic sense) the rationale behind attempting to eliminate every last mite from a colony with 4 doses every 5 days, because of this subsequent mite importation from outside.
    You'll never eliminate them all. But there is a distinct difference between a mid winter treatment with OAV and one done mid season. The mid-season application only attacks mites not protected by cappings, and is apparently about 95% effective, so, you get roughly 95% of only 1/4 of the mite population, hence the desire by some folks to do multiple applications over a period, so they expose the entire population. Still wont get them all, but, at least get the majority.

    I take a different approach. Mid season we dont bother with OAV, to much effort for to little return. I'll do a formic flash mid season. Reading will suggest one formic flash application will attack 90% of mites, including those under cappings. You are in England, I believe formic flash is an acceptable mite intervention over there too. It's a quick, easy and cheap way to intervene and attack the mite population without setting back the bees, one flash application is roughly equivalent to OAV done 3 or 4 times on a schedule. Even purchasing thru the spendy retail channels, formic is not really that expensive. A 4 liter jug goes for 48 bucks here, and that's enough to do about 130 formic pads. Works out to around 36 cents for the acid, then a couple pennies for the carrier, and cost goes down to under 25 cents if you are doing larger numbers and buying the 20 liter jugs. Most i know around here use meat pads, a few just use paper towels. The setup is really simple and quick. Using the example of doing 20 colonies, you put 20 of the meat pads in a plastic container, pour in 600ml of acid then put the lid on the container and leave it sit for a few hours to let the pads soak up all the acid more or less evenly. Take the container out to the bees, pop a lid, smoke the bees off the top bars, drop the pad on the area clear of bees and put the lid back on. Just be careful of temperatures, dont do the flash when it's to hot thru the day.

    We usually do a round of formic after spring honey comes off, and I'll put the pads on in the evening so they dont get immediately exposed to the daytime high temps.

  6. #5
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    Default Re: Every last mite ?

    Mid-season, steady-state and only about 30% of mites are phoretic. You'll get a maximum of 95% of them. Mathematically I reckon it would be better to restrict any treatments to broodless periods (or perhaps times when there's markedly reduced sealed brood). A monthly - or whatever - schedule might also be problematic with honey supers on.
    The Apiarist - beekeeping in Fife, Scotland

  7. #6
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    Default Re: Every last mite ?

    The purpose of repeated applications isn't to get every mite, it's to get them as they become susceptible to the treatment.

  8. #7
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    Default Re: Every last mite ?

    Quote Originally Posted by dudelt View Post
    I believe you are on the right path. Eliminating every mite is close to impossible. Knock them down to the point where they stop causing major issues and move on. There is a point of diminishing returns with treatments. A full treatment to kill 1,000 mites is worth the time taken. A full treatment to kill 1 mite, probably not worth the time and money. Would you really want to spend $15.00 on a MAQS treatment to kill only one mite? Marion Ellis has the right idea.
    I think Marion Ellis is right - but (having been reminded of the percentages of phoretic mites by grozzie and fatshark), and bearing in mind the discovery of Samuel Ramsey and the need for healthy winter bees - on further reflection maybe a compromise solution is the better approach ...

    So I think from now on it'll be a single course of 4 x 5-day treatments in late summer, followed by my usual broodless 'mid-winter' treatment (which is due any day now ...). It may well be that the single mid-winter treatment following so soon after the multi-dose renders it somewhat redundant - but I'll consider that to be part of a 'belt and braces' approach.

    Thanks for the input - it's been very useful.
    LJ
    A Heretics Guide to Beekeeping http://heretics-guide.atwebpages.com/

  9. #8
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    Default Re: Every last mite ?

    That's pretty much my regime LJ. My bees don't go to the heather so I treat straight after taking off the summer honey. I then always treat midwinter. If you treat early enough to protect the winter bees from Varroa/viruses then there still some time left with brood still being reared for the residual mites to replicate. The likelihood is that early (enough) treatment leaves higher mite levels midwinter. Indeed, you could even argue that if there's no midwinter drop on treatment then it's likely the colony was treated too late in the season!

    Since we're lucky enough in temperate climates to have a broodless period it's an ideal opportunity to 'give them an additional kicking'.

    My mite levels were so low this autumn that I added Apivar strips to a few hives just in case the OA had somehow 'failed' ... it hadn't. I got no additional drop.
    The Apiarist - beekeeping in Fife, Scotland

  10. #9
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    Default Re: Every last mite ?

    Quote Originally Posted by little_john View Post
    ...
    This has caused me to challenge (in the academic sense) the rationale behind attempting to eliminate every last mite from a colony with 4 doses every 5 days, because of this subsequent mite importation from outside.
    ...
    - with a single dose (say) being given monthly, or bi-monthly throughout the season -
    ...
    LJ
    They say mite population doubles in three-four weeks during brooding period. Meaning the answer, again, depends on initial infestation level.

    In this study they counted mites on foragers leaving or entering hives claiming that mite migration alone could be a factor in the fall spike in mite numbers.

    According to their results, in the fall, 2% of both leaving or returning foragers have phoretic mites on them. Not sure they have documented the frequency at which foragers enter the wrong hives (or foragers with mites on them). If 1% of returning foragers are from other colonies, which is a great overestimation, then there will be one mite migration event per 20,000 foraging flights (provided this mite changes the host). Of course, migration rate could be much worse with collapsing hives in the vicinity.

    Besides, the same number of 2% for both leaving and entering bees most probably means they just counted bees from the same colony. In addition to the possibility of no lost foragers, their sampling technique just isn't sensitive enough for picking up the mite migration events.
    Confusing, to say the least.
    Last edited by baybee; 12-08-2018 at 05:52 PM.

  11. #10
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    Default Re: Every last mite ?

    There's reasonable data on drifting ... 1% over three days is one figure. The other thing that reflects this is the microsatellite analysis to show parentage ... something like 13-45% are from a queen other than the one in the hive if I remember.

    The other work on mite migration is Mangum if ABJ about 7 years ago, summarised here.
    The Apiarist - beekeeping in Fife, Scotland

  12. #11
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    Default Re: Every last mite ?

    THis year, I treated 4 times or so (with horizontal hives, not sure of efficacy, no bottom board, hence the multiple treatments). Mite counts were at 2/300 via alcohol wash - in September. I did no summer treatment, I did do summer splits.

    Someone I was mentoring started with a package, had a mite count of 6/300 in Aug or Sept, then had 60+ mites/300 in early Dec. Those were imported.

    So, I will be continuing solely treating during broodless periods for my overwintered hives and splits - I will start treating in late Sept, and treat probably twice a month, after 2 different fly days each month. That's when they seem to go robbing - Oct, Nov, or maybe even Dec - hives are weakening from mites and robbers can't be repelled.
    I'm not going to follow this treatment regimen because I want to kill every last mite... but because if an incursion of mites from robbers (or bees seeking sanctuary in a strong hive, fleeing a dying one) happens to a hive, I want it to be impacting the bees for a short time. I'll be able to tell from the mite drops whether the bees went robbing and brought back mites. They will be markedly higher than past mite drops post OAV, or staying the same, not 90% lower. Saw that with another beek who was using OAV in Sept and again in OCt, then had to do again in Nov and now the Dec one is very low mite drop post OAV.

    I

  13. #12
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    Default Re: Every last mite ?

    Quote Originally Posted by baybee View Post
    They say mite population doubles in three-four weeks during brooding period. Meaning the answer, again, depends on initial infestation level.

    In this study they counted mites on foragers leaving or entering hives claiming that mite migration alone could be a factor in the fall spike in mite numbers.

    According to their results, in the fall, 2% of both leaving or returning foragers have phoretic mites on them. Not sure they have documented the frequency at which foragers enter the wrong hives (or foragers with mites on them). If 1% of returning foragers are from other colonies, which is a great overestimation, then there will be one mite migration event per 20,000 foraging flights (provided this mite changes the host). Of course, migration rate could be much worse with collapsing hives in the vicinity.

    Besides, the same number of 2% for both leaving and entering bees most probably means they just counted bees from the same colony. In addition to the possibility of no lost foragers, their sampling technique just isn't sensitive enough for picking up the mite migration events.
    Confusing, to say the least.
    Quote Originally Posted by trishbookworm View Post
    THis year, I treated 4 times or so (with horizontal hives, not sure of efficacy, no bottom board, hence the multiple treatments). Mite counts were at 2/300 via alcohol wash - in September. I did no summer treatment, I did do summer splits.

    Someone I was mentoring started with a package, had a mite count of 6/300 in Aug or Sept, then had 60+ mites/300 in early Dec. Those were imported.

    So, I will be continuing solely treating during broodless periods for my overwintered hives and splits - I will start treating in late Sept, and treat probably twice a month, after 2 different fly days each month. That's when they seem to go robbing - Oct, Nov, or maybe even Dec - hives are weakening from mites and robbers can't be repelled.
    I'm not going to follow this treatment regimen because I want to kill every last mite... but because if an incursion of mites from robbers (or bees seeking sanctuary in a strong hive, fleeing a dying one) happens to a hive, I want it to be impacting the bees for a short time. I'll be able to tell from the mite drops whether the bees went robbing and brought back mites. They will be markedly higher than past mite drops post OAV, or staying the same, not 90% lower. Saw that with another beek who was using OAV in Sept and again in OCt, then had to do again in Nov and now the Dec one is very low mite drop post OAV.

    I
    If we accept the highlight in first quote as being reasonably true, and that viral titres are relative to mite load and take a number of brood cycles to be brought under control, should we not start at the earliest convenient date to start hammering the varroa in order to raise healthy wintering bees and avoid possible early fall collapse from the exponential mite growth in the face of normal bee population reduction?

    Your relative treatment time compared to mine is different for certain. I agree that ongoing treatment into fall may well be necessary if one is getting indrift from surrounding colonies. I just dont see the wisdom in considering earlier mite treatments as being wasted.

    Perhaps I am misunderstanding something.
    Frank

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