mite count on Pupa threshold

Discussion in 'Pests and Diseases' started by Daniel Y, Aug 28, 2012.

  1. Daniel Y

    Daniel Y New Member

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    I just pulled about 20 drone pupa from there cells. At 10 pupa the mite count was at 1.5 mites per. at 20 the count had fallen to 1 per. I suspect that count is low but don't recall what the number is where I really need to treat. I expect to treat this hive before winter sets in regardless. Jsut hoping someone can give me the number for a mite count on pupa. I can find it for drop count no problem.
     
  2. efmesch

    efmesch Active Member

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    I don't think the count is based on how many mites/pupa but rather how many pupas are infested in the hive. You seem to have close to 100% infestation. I think you're on the verge of a serious outbreak and would recommend that you initiate treatment immediately. That could mean "simply" removing all drone brood from the hive (not so simple if they are mixed in with other brood that you want) or choose any one of the other treatments discussed in the relevant threads.
     

  3. tecumseh

    tecumseh New Member

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    no matter what the process mite count needs to be somewhat 'normalized' to the season.... basically early in the season you should expect varroa population to be low and later in the season high.

    I often test for varroa by plucking drones but since I am do not treat this information does not promote any direct action. indirectly a high count gets those hives used for splits and the low number for drone production and sometimes honey. this is almost always done in the early part of the year. basically the protocol is if I see a varroa on a drone pupae here and there I figure this is within bounds... more than one varroa or when single varroa on drones pupae reaches +30% get a hive a high varroa count designation.
     
  4. Daniel Y

    Daniel Y New Member

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    Efmesh, Actually I found less than half with mites since nearly any pupa with mites had more than one. Two of the first ones I found with mites actually had three. I was not thinking about the percentage of pupa infested as I was counting. Still I agree that is enough that the next round of drone brood could very well be a 100% infestation. The good news is that frame did not get returned to my hive. What other mites are in there will die in the cells since I put it in the freezer. I may be at about 40% infestation right now.

    I have never seen a mite on an adult bee either. Hopefully that means my bees have some pretty good hygeneics toward Varroa.

    I am in the process of getting Oxalic Acid and building a vaporizer. I know that this requires more than one treatment but am not certain just how many treatments are needed or how often. I was thinking once a week for at least 5 weeks in a row.

    Here is my reasoning. any brood is uncapped for 8 days. So first treatment at least 25% of the brood is still uncapped, 75% uncapped and avoided treatment. The end of week one 25% of the caped brood has emerged and introduced any mites to uncapped brood cells. they will be treated during the second treatment. Again for third and forth treatment at which time 100% of all brood will have emerged and every cell int he hive will have been treated at least once while it was open. The 5th week is just insurance due to nothing being perfect. IN addition I am jsut weeks away from my queen slowing down for the year. treatment will be far more effective with less brood in the hive.

    My other two concerns at this time is the level if any of Nosema and Tracheal mites. I don't have a microscope so cannot examine for those. I hate to just treat because there might be a problem. But at the same time my instinct about varroa seems to have been right on the money.
     
  5. PerryBee

    PerryBee New Member

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    I have never read anything about mite "counts" on exposed pupae. The other thing I would be extremely wary of is relying on "seeing" mites on adult bees. Mites often spend time hiding under the abdominal plates on the underside of bees.
    Oxalic acid (in vapour form) can be used to knock back mite levels (even during brood periods) if used several times at regular intervals. I remember reading somewhere that weekly (or every 10 days) for a 3 week period? Not sure about 5 weeks.
     
  6. Daniel Y

    Daniel Y New Member

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    Perry, Here is what I have read and like about OA. First it is not considered a chemical treatment. Second it is mild and I have heard you could treat with as much as 8 times the recommended dosage before worry about overdose. Third it is said to be extremely effective and the only treatment I have seen claimed to kill 100% of the mites, that is exposed mites though.

    Being that I am on the verge of winter here, brood will be reduced and I assume not much drone brood wil be produced during teh winter, as well as I will be treating at all that I can live with just three treatments. Btu it will be a nerve wracking winter for me, lol. Just kidding.

    IN truth I am nos scrambling to get the parts for my fogger. I just ordered the acid on e-bay and the SS fittings online as well. Now for the week long wait for anything to arrive. I will be building my chamber with aluminum rod and a glow plug in the mean time.

    Not that I am taken by surprise to find varroa. Btu I am a bit surprised at my reaction now that I ahve found them. It is a bit unsettling to think something is in my hive harming the bees. I bit like someone breaking into my house. Maybe I am just overworked lately. I have been much busier than I shoudl be. But overall I am a little bit surprised at how this all hit me.
     
  7. PerryBee

    PerryBee New Member

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    I have said it before but I will repeat it again on the offhand it may perhaps ease the burden/conscience of a few new keeps.

    When I first started keeping bees (not all that long ago) I was convinced that I could do it "differently", that somehow under my vigilant watch, my bees would not fall victim to many of the dreaded maladies that seemed to pervade the beekeeping community at large.
    It did not take long for reality to humble me. You can do everything right (and believe me I do not fall into this category) and still experience hardship and heartbreak.
    Discovering/recognizing your bees have a problem is a huge step in the right direction, and should be a boost to your confidence, confirming that indeed you are on the right path.
    :thumbsup:
     
  8. efmesch

    efmesch Active Member

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    Actually I found less than half with mites since nearly any pupa with mites had more than one. Two of the first ones I found with mites actually had three. I was not thinking about the percentage of pupa infested as I was counting. Still I agree that is enough that the next round of drone brood could very well be a 100% infestation. The good news is that frame did not get returned to my hive.

    What other mites are in there will die in the cells since I put it in the freezer. I may be at about 40% infestation right now.
    You might consider inserting frames with drone cells to serve as a "magnet" for varroa females to lay eggs on the drone larvae and then regulary remove and freeze those frames before emergence.
    I have never seen a mite on an adult bee either.
    It's not a pretty sight seeing them on the bees, either stationary or walking around.

    Hopefully that means my bees have some pretty good hygeneics toward Varroa.
    I "second" that.

    I am in the process of getting Oxalic Acid and building a vaporizer. I know that this requires more than one treatment but am not certain just how many treatments are needed or how often. I was thinking once a week for at least 5 weeks in a row.
    The current recommendations in Israel are to use Check-Mite (left in the hive at least 6 weeks) or give three weekly treatments with Amitraz (=Tak-Tik). Basically your reasoning is in agreement with the local timing lapse but you are being super cautious. It could be that the limitation to 3 treatments is because here we are dealing with a selectively toxic miticide.

    The method we use is to take a strip of filter paper (about 2X7 cm) chemically treated so that it smolders slowly without a flame. The strip is folded lengthwise to form an upside down "V". Two drops of amitraz are driopped onto the strip, in the middle. After a short drying wait, it is lit and pushed into the entrance of the hive where it smolders, smokes and burns, releasing the amitraz into the hive. This methohd also eliminates tracheal mites.
    The big problem is the appearance of resistant mites and this issue is constantly being monitored.

    Let Perry's words serve as some consolation. You can be doing everything just right and your bees will still pick up an infestation. It's not your fault and the only thing you can do is treat the problem as best you can.
    I'm very interested in hearing how things go with the oxalic acid treatment.
    Keep us posted.
     
  9. heinleinfan

    heinleinfan New Member

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    What others have said: some times things just happen. You can do things 100% perfect as a keeper, but your bees fly all over. You can't control what happens in other bee yards and in feral colonies, so sometimes your ladies are going to bring things home with them.

    With varroa...I actually approach dealing with varrao like I used to approach dealing with fleas and ticks on my outdoor animals. They were flat out going to have them. There's no way I could have possibly kept them free of fleas/ticks without constant chemical treatments, which I personally don't like to do. But, I could keep a good eye on them and use preventative natural methods, made sure they never got enough to threaten their health...and gave them a flea bath if I absolutely had to.
     
  10. Omie

    Omie Active Member

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    If it was me, I'd just start scraping off the capped drone larvae in that hive. That would put a serious dent in the mite's breeding nursery plans. Get 'em where they breed. :) A weekly round of that over the next 3 or 4 weeks would make a noticeable difference. By that time the production of drones will drop off anyway.

    Oxalic acid treatment *is* a chemical treatment. Hey it ain't fairy dust- it kills mites. Whether it is considered to be harsh or mild or 'man-made' or 'organic', magical, natural, blah blah blah...is totally up for debate ...hopefully elsewhere! ;)

    All beehives have mites. If a particular hive of mine can't handle a normal load of mites with my occasional splitting and drone culling assistance, then I prefer that particular hive to die off or be requeened.
     
  11. tecumseh

    tecumseh New Member

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    a snip..
    I have never seen a mite on an adult bee either. Hopefully that means my bees have some pretty good hygeneics toward Varroa.

    tecumseh:
    as Perry has suggested above most mites attach on the underside of bee (bottom side of abdomen) so you are unlikely to see adult varroa. hygienic bees come in two flavors. lets call the first brood disease sensitive (which can be field tested) and the second varroa sensitive hygienics (there are some behavioral clues relative to capped brood but not easy to test in the field). most surviving bees in today climate will like have some degree of brood disease sensitive hygienics. a 40% infestation rate would suggest that the hive does not have much varroa sensitive characteristics. 'by the book' varroa infestation rates at or about 30% suggest the hive has large problems and is likely well on the way to crashing.

    I would be curious to know if the existing frames contains newer or older comb.
     
  12. Daniel Y

    Daniel Y New Member

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    Tecumseh, All but 5 of my frames are brand new this year. This particular frame has had comb drawn in it for no more than 60 days. this was no question the one and only brood ever in it.
     
  13. tecumseh

    tecumseh New Member

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    thanks for the answer.

    so 5 frames do have some age on them and the newer frames are to the outside of the boxes with some significant drone brood in the one or two frames toward the outside wall? <guessing that here is where you were plucking drones????
     
  14. Daniel Y

    Daniel Y New Member

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    Let's see, I inspect my hives standing at the east side counting frames 1-10 nearest to furthest from me. so the western most frame is number 10. I hope that makes since. If I recall correctly this frame was number 9 of the lower deep with 10 being all honey. So yes it was an outermost frame of brood in the hive. Also keep in mind it was an empty frame that was placed temporarily due to lack of foundation at the time I needed it. This is the reason I was removing it in the first place. I found it full of brood so wanted to allow the brood to emerge. Once most of the brood had I used the rest to do my pupa inspection.
     
  15. tecumseh

    tecumseh New Member

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    if you can imagine the primary brood nest as a basketball (set inside a square box) the drone brood and queen cells are typically situated on the outside surface area of the basketball. so two frames (9 and 2 using your own reference) should contain the highest number of drone brood and this is the locations where you should expect to see the largest concentration of varroa. the real problem with a high varroa infestation rate is about this time of year the brood production will wane and the production of drones will sometimes halt altogether. this then leaves the still growing varroa population to go for the next best (from the varroa point of view) resource for food and reproduction which is worker brood.

    your numbers could be a statistical (not so random) problem... then again it may be quite accurate. here I would likely use some soft treatment to get the hive thru the next few month and place a mark on it to use this hive for nuc rearing come spring time. that is... however large or small the hive might be I would break it into as many nucs as possible come spring time and at that time kill the queen outright.