Threshold for treating Varroa

Discussion in 'Pests and Diseases' started by d.magnitude, Aug 29, 2010.

  1. d.magnitude

    d.magnitude New Member

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    I just did a count for each of my 3 hives for a mite drop onto a sticky board after 48 hours. I used corrugated plastic (the kind with a grid printed on it) coated with Vaseline slid under each SBB.

    There were about 30, 21, and 60 mites on each board respectively. I have to say "about" as they are pretty hard to spot with all the debris and varroa-colored-pollen all over the boards. Next time maybe I'll bring a magnifying glass. Btw, I did this a couple of months ago for kicks, and found less than 5 per hive (but this is their first year).

    I just wanted to ask if anyone else uses this method, and if so, what is the threshold before you treat for varroa? I seem to remember reading somewhere that you should treat if you find a count of 50 or more after 24 hours. If that's the case I should be in the clear, but if I find I need to treat, I'll probably try a powdered sugar shake.

    -Dan
     
  2. Iddee

    Iddee New Member

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    One count is not reliable. You should do 3 days worth and then use the average drop. Then 50 is a good threshold to use, although that isn't locked in stone. A monthly 3 day count will tell you if they are increasing, decreasing, or staying the same.
     

  3. camero7

    camero7 Member

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    I think an ether roll or an alcohol wash is much more reliable and will give you all the information you need to decide whether to treat or not... anything over 10 mites with those methods, I'd treat.
     
  4. d.magnitude

    d.magnitude New Member

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    Thanks,
    I may try an ether roll next time. I've read about it, but have never come across any numbers about how many mites is "too much" with that method. How many bees do you try to get in the jar? Perhaps I should ask what volume of bees? 1/3 of a quart jar? Has anyone tried a powdered sugar roll as an alternative to ether?

    I do like the idea of not making a separate trip back to the hives in 2-3 days to check the boards (unfortunately, they're not in my backyard). Also cleaning the "goo" off the boards afterward is never fun.
     
  5. Iddee

    Iddee New Member

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    A sugar roll, in my opinion, is as accurate as an ether roll, and it feeds the bees rather than killing them.
     
  6. tecumseh

    tecumseh New Member

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    The literature suggest that none of the methods are very reliable. <this is likely at least a good proportion of why Iddee #2 comments should be highly considered. This pivots on a standard statistical practice that when you know you have a large error term in any one data point... then simply repeating the sampling enough times and the error terms will council them selves out.

    I have done sugar roll and this is no more precise than anything else. You don't kill the bees but counting at the end of the process requires a pretty good magnifying glass. some kind of funneling device is necessary for me to get a good sample in the quart jar in the first place. with the sugar roll method where you take the sample in the nest somewhat to highly effects results. along the edges or the brood nest (not from honey supers) should give you a more reliable number. as suggested in the paragraph above the average of multiple samples should yield a much more reliable number. I noticed in one of the later edition of the ABJ that a canadian bee science guy had developed a double lidded screen jar (think two mason jar rings glued together in opposite directions with a bit of small hardware cloth in between) for making the sugar roll process a bit easier as a field test. you put the bees and powdered sugar in one end, rolled them around and then shook excess powder and mites to the other bottle. the mites (supposedly) stood out pretty well on the wall of the other jar.

    good luck and do report back your results if you have the opportunity.
     
  7. Iddee

    Iddee New Member

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    Using a large mouth peanut butter jar makes it easy to scoop them off the open brood.

    Sprinkling the sugar into a silver or white pan with a 1/4 inch of water in it dissolves the sugar and makes the mites stand out. They are very easy to see.
     
  8. rast

    rast New Member

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    I also just use a 3 day "normal" fallout count. To make it easier, use a spray nonstick cooking oil instead of Vaseline on the count board. Also you kinda need to know your bees, I don't know how else to put it. The more "hygienic" a hive is, the more mites they will groom off themselves and each other, hence, a higher mite count on a board. But a lower count in the capped brood where it counts.
     
  9. d.magnitude

    d.magnitude New Member

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    Well, I decided to go ahead and try the powdered sugar roll method today, but ran into a hitch or two.

    I did get some pointers on the Penn State Xtension page. Namely, I should try to get 200-400 bees (1/4 - 1/2 cup) in the jar, and a count of 10-12 mites per 100 bees may (according to them*) warrent treatment. They went on to say that if there is brood in the hive (let's hope there always is), you should assume you have double the count of mites that were shaken out of the jar. So in that case, 5-6 mites shaken out per hundred bees might warrent treatment*. Now there are some numbers I can work with! Just what I was looking for.

    Iddee, your tip about shaking the sugar out into a pan of water was brilliant! Dissolved the sugar like a charm. Tec, your tip about using some kind of funneling device to get the bees in the jar- also brilliant! I should have listened to it. :oops: I just shook, brushed, or otherwise tried to coax the bees into my wide-mouthed jar with little success. I got 1 /8 cup of bees in there at best- not nearly enough for any kind of good sampling. I guess they just did not want to cooperate. After I found it was not working so well, I thought I would spare the rest of my hives from the same treatment.

    I plan on returning well equiped with a pan of water and a funnel or a bent piece of sheet metal. Oh, and a camera. Wish me luck!
     
  10. tecumseh

    tecumseh New Member

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    snip..
    They went on to say that if there is brood in the hive (let's hope there always is), you should assume you have double the count of mites that were shaken out of the jar.

    tecumseh:
    this multiple is seasonally adjusted by the quantity of brood in the hive. therefore a higher number in the spring when you have lots of brood and lower in the fall of the year when brood relative to live bees is lower.

    I found one of those old fashioned light fixture reflectors works quite well for a funnel. I simple opened up the hole where the light should be and glued on a ring from a mason jar.

    and yes most certainly good luck...
     
  11. d.magnitude

    d.magnitude New Member

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    Well, I never did get the funnel rigged up, so I did another 48 hr. stickyboard and just pulled them today. My results were (averaged to a 24 hr. drop) 49, ??, and 20 mites. It seems hive #1 rose dramatically, and #3 dropped a bit since last time. I guess there is always the chance that I mixed up the boards between pulling them and counting, but I don't think so. I think I'll begin a powdered sugar dusting regimen for all the hives soon.

    Hive #2 was ?? on the mite count. I'm afraid it has much bigger issues now. There were what seemed to be too many wax cappings and wax moth larvae covering the board to even do a mite count. Easily 100+ wax moth larvae. This has been the weakest of the hives for a while, and I have to admit I made a MAJOR mistake recently. I've been feeding it syrup to help it along, which it has been taking very slowly. Last Thurs. I gave it a batch with HBH to encourage them to take it, but I also cracked the outer cover for some ventilation. When I visited today, I saw lots of bees going thru that top opening and a little fighting at the bottom entrance. I did not have the time or the gear to go into the hive and investigate, but I closed the top and stuffed a little grass into the already-reduced bottom entrance to reduce it some more. I fear they may be doomed...

    My question is this: The wax moths could not have just moved in since two days ago, laid eggs, and had them hatch already, could they? Was this hive destined to fall to the wax moths anyway? And is there anything I can do about it now? Unfortunately, I can't get to them again until Monday at the earliest due to scheduling, but even if I was equipped, I wouldn't have know what to do about it today (other than the closing off I did do).

    I'm pretty heartbroken, and feel pretty guilty and ignorant at the moment. But I did start a nuc from split this year, so hopefully I'll at least go into the winter with 3 colonies, just like I started.
     
  12. tecumseh

    tecumseh New Member

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    as myself and another local beekeeper have decided with hive #2 finding and preserving the equipment (vs total wax moth destruction) makes for a successful day. which is to say preserving the capital of the pull wax + equipment is more important than maintaining some count number of hives.

    d. writes:
    The wax moths could not have just moved in since two days ago, laid eggs, and had them hatch already, could they?

    tecumseh:
    I am not exactly certain of their life cycle but yes they work extremely quick and yes the hive could have been destined to fail (although the cause may be only generally associated with the wax moth). it was likely something else and some post analysis of the problem might be useful for your own understanding. if the sticky board was nasty with mites that could reasonable be your answer.

    what to do somewhat depends on what is in the box when you get back to it. reduce the hive to a space the population can cover. if there is very little population you may wish to combine. freeze any tainted frames for a minimum of 24 hours. those with little food value (honey or pollen) and unbrooded up wax I usually just set out into the sunshine since the wax moth really have no interest in just pure wax.

    I do think you have learned (at least I hope so?) that feeding does have it downside and that feeding without tight equipment with hive entrance reducers in place is somewhat to highly ineffective.
     
  13. d.magnitude

    d.magnitude New Member

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    Thanks Tec, I have plastic foundation in these hives, so I'll walk away with my foundation at the very least (but I still hope to do better than that). This hive was on the weak side (I believe) because of two breaks in the brood cycle due to supercedure. I did get an idea of the mite level through the debris on the sticky board- it actually did not seem that bad, similar to my hive that had 20 or so.

    Having previously underestimated the tenacity of wax moths, I have a couple of questions about how I might proceed:
    "reduce the hive to a space the population can cover"

    I'm afraid that if I reduced this hive to a size the population could cover, that might only be a 5-frame nuc. And I don't think a nuc that size would have much chance of building and making it thru the winter at this point. Even if it was a single 10-frame deep, that would be dicey, and I might have better luck combining. Thoughts?

    "if there is very little population you may wish to combine'

    If I combine, say, one 10-frame deep from this hive with another strong hive, does it have to be wax moth free, or can I count on the strong hive driving out and destroying any remaining moths and larvae in short order? If I did this, I reckon I would try to use the 10 least-destroyed frames from my hive, freeze the rest and save them for another day.

    "freeze any tainted frames for a minimum of 24 hours. those with little food value (honey or pollen) and unbrooded up wax I usually just set out into the sunshine"

    I guess I'm not completely sure what you're suggesting here. After these frames are frozen/sunned out, are you suggesting I just put them away til next year? Or are you saying I would then turn around and give these back to my reduced hive, or "treat" them as such before using in my new combine?

    Thanks for bearing with me, I want to make the most of this situation. Anyway, depending on the state of the hive when I see it, this may all be moot; I'll let you know. And yes, I have learned my lesson about the dangers of feeding and how seriously destructive robbing can be.
     
  14. d.magnitude

    d.magnitude New Member

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    Wow, these bees always throw me for a loop. :confused: Judging from the wax debris, and worms, and occasional moth I found on my stickyboard, I was sure I had wax moths in this hive. I went today, equipped to break it down and put it in the freezer. When I opened it up, I found NO evidence of wax moth damage- none. Could it be that the debris on the sticky board was just from the robbing going on in the hive, and the wax moths just made a home in that cozy space on the board under the SBB? That's my best guess.

    Unfortunately, this hive's still got big problems. There was robbing going on (it may have subsided when I reduced all entrances down), and I conclusively found this to be a laying worker hive. Almost every available cell was littered with eggs, some even on top of pollen! Workers really are awful layers! My question is where to go from here?

    Should I shake out this hive and just let all the bees find their way into one of my other 3 colonies? If so, what should I do with all the eggs, pollen, and nectar left in these frames? Leave them out (100 yards away) and just let it get robbed out before putting in storage? I could put them right on top of my other hives to be cleaned out before storage, but I don't want my other hives moving honey up into these boxes; they're pretty well organized at this point.

    Or should I try to reduce this hive down to one deep, and combine with another strong colony already in 2 deeps? Would the laying worker part "straighten out" in the presence of the queenright colonly?

    Thanks for the advice. I should see about changing this to a new thread.
     
  15. Iddee

    Iddee New Member

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    I would shake all the bees out of the LW hive, freeze it, then spray it with BT and put it away for the winter. If this were April I might try to save it, but in Sept. it is a waste of time and money.
     
  16. tecumseh

    tecumseh New Member

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    d....
    it seems you have identified primary cause in that superscedure suggest that either the queens produced were of weak genetic material, poorly mated or as I SUSPECT HERE that multiple superscedures may mean that the unit was wrestling with serious mite problems and multiple superscedures breaks the mite rearing cycle. another suspect to add to you cast of 'most likely suspects' would be nosema. this latter suspect is actually numero uno on my 'most likely suspects' list these days. <I use suspect here in that I have no ABSOLUTE proof but I do know when I apply remedies the problem does (or does not) quickly recedes;

    a d. snip...
    I'm afraid that if I reduced this hive to a size the population could cover, that might only be a 5-frame nuc. And I don't think a nuc that size would have much chance of building and making it thru the winter at this point. Even if it was a single 10-frame deep, that would be dicey, and I might have better luck combining. Thoughts?

    tecumseh:
    this might be a worthwhile thing to try and you have little to loose. I know folks do overwinter in small size boxes in many areas. I have overwintered here in units as small as baby nucs boxes plus 5 frame mediums and deeps. Details for overwintering in small boxes at your location would require someone a bit closer to the area than myself. Bjorn or Michael Palmer would be the two names I place at the top of the list for such detail.

    a d. snip..
    If I combine, say, one 10-frame deep from this hive with another strong hive, does it have to be wax moth free, or can I count on the strong hive driving out and destroying any remaining moths and larvae in short order? If I did this, I reckon I would try to use the 10 least-destroyed frames from my hive, freeze the rest and save them for another day.

    "freeze any tainted frames for a minimum of 24 hours. those with little food value (honey or pollen) and unbrooded up wax I usually just set out into the sunshine"

    tecumseh:
    freeze any frame you have a question about for 24 hours. this destroys the eggs and reduces the larger problem to a manageable level. 24 hours or so later you can reuse the frames in any way you see fit. slightly infested frames are reclaimable by a good strong hive but I would not want to place a highly infested frame on any hive (and basically I can't see the egg of wax moth so why take the chance?)

    another d snip..
    I guess I'm not completely sure what you're suggesting here. After these frames are frozen/sunned out, are you suggesting I just put them away til next year? Or are you saying I would then turn around and give these back to my reduced hive, or "treat" them as such before using in my new combine?

    tecumseh:
    once frozen for 24 hours you can go either way.

    a d snip..
    Thanks for bearing with me, I want to make the most of this situation. Anyway, depending on the state of the hive when I see it, this may all be moot; I'll let you know. And yes, I have learned my lesson about the dangers of feeding and how seriously destructive robbing can be.

    tecumseh:
    absolutely no problem and your are very much welcome. you write well enough I can easily imaging your problem. do report back. since I have large number of migratory beekeeping hives (bweaver and company) set down here each year I am well versed in the topic. I still loose a hive/small nuc from time to time.

    and good luck...
     
  17. d.magnitude

    d.magnitude New Member

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    Iddee, Thanks, I may do just that today. My only question is that these frames are loaded with eggs. Is it ok to leave that much "protein" sitting around all winter, or should I figure out some way to have my other bees clean it up? Also, is the BT you're referring to still not labeled for beekeeping use? I love the idea of using BT to protect equipment, but I feel funny about using an "unapproved" product on honey I may sell.

    Tec, Not sure if you read my post #14; this no longer seems like a wax moth problem, but a laying worker hive. What do you think of my "false wax moth reading" theory? Please, add any of your knowledge to my LW problem. By the way, I have read up a bit on overwintering nucs, and I have one nuc (5-frame deep, with two 5-frame meds) I'm going to try to overwinter (I have high hopes). I'd be game for overwintering a reduced version of this colony, but not aqueenless version!

    Thanks again guys. This forum has taught me so much. I'm pretty sure I've gotten some bad advice from beeks I've personally met, so I'm going to consider this site, collectively, my mentor for now.
     
  18. Iddee

    Iddee New Member

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    It wouldn't hurt to allow them to clean it up, if it is placed far enough away to prevent a robbing incident from beginning.

    I wouldn't recommend it if I didn't feel comfortable with using it. I am not a scientist in the field of biological chemicals, or whatever it would be called, but I am comfortable using Zentari for certain larva.
     
  19. d.magnitude

    d.magnitude New Member

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    Before I go through with this LW hive shake out, I had a last minute thought. I still have a hive that I have not confirmed to be queenright. It's been very aggressive for months now, so I don't think the "meanness" is necessarily due to a lack of queen, but it has prevented me from being extremely thorough in my inspections. Last time, I got 75% of the way through that hive, and still saw no eggs/larvae before I had to retreat.

    I'm thinking I should put a frame w/ eggs in this hive to make me comfortable, and then wait a few days to a week for them to accept this (or not, if they don't need it), before shaking out my laying workers. I'd hate for a laying worker to find her way into this hive when it's vulnerable and turn it into a LW hive as well. Decent plan?

    About the Zentari, I'm still up in the air. It does appeal to me as a convenient, safe control, and I've used BT aplenty in my days of organic farming. I wish it were "labeled", but then again we throw all kinds of stuff in our hives that's not "labeled" for beekeeping use (sugar, essential oils, Crisco etc.). I'll have to revisit the "Certan" thread.
     
  20. Iddee

    Iddee New Member

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    If I eat a certain substance on a regular basis on my veggies, why should I be worried about eating a bit of it on my honey just because some politician hasn't received a large enough kick back to approve it in writing for beehives?