Need help with heavy mite load
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  1. #1
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    Apr 2018
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    Santa Cruz, CA, USA
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    Default Need help with heavy mite load

    Need some advice as to whether I should use something besides OAV for one of my hives. I have 2 hives - one is 2 years old and another started as a nuc this year. I use the sugar roll technique written by Mich State and referenced by Nancy throughout the forum. My established hive is very healthy, consistently with mite counts of 3 or less (1/2 cup of bees). The nuc had very high counts from the very beginning and remains so now. I have treated both hives with OAV three times now (spring, summer, fall) and still have a count of 18 mites in the nuc. Maybe wrong, but I've treated the healthy hive each time I've treated the new hive since they are within 10 feet of each other. When I treat, I do it every 4 days for 4 times.

    I'm in California - still fairly warm and bees still bringing plenty pollen back to hive.

    Thoughts?

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  3. #2
    Join Date
    Oct 2008
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    Turnbow Hollow, Tennessee
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    465

    Default Re: Need help with heavy mite load

    Thermal treatment of varroa mites will kill the vast majority of the reproductive varroa mites which reside in the brood and capped brood comb. I am not sure what your daytime temperatures are but it may still be too warm to use Mite Away Quick Strips or Formic Pro which is a chemical treatment that kills reproductive varroa mites. OAV is a very good treatment for phoretic varroa mites. If your daytime temperatures are still too high for chemical treatment, try a Mighty Mite Killer. https://www.beehivethermalindustries.com/shop/

    Here is another great place to get more information.

    https://www.facebook.com/groups/275791919813444/

  4. #3
    Join Date
    Feb 2013
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    Humboldt Co., California
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    557

    Default Re: Need help with heavy mite load

    Go the Honeybee Health Coalitionís web site and read they Varroa control manual. Pay particular attention to the available products section as it relates to the temperature ranges necessary for them to be effective.

    I always have concerns about treatments this late in the year for fear of it being too late to control mite /viral complex in winter bees as well as a concern for losing a queen this time of year.

    Regardless, I would still try treating as I donít think there is much to lose.

  5. #4
    Join Date
    May 2011
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    Algoma District Northern Ontario, Canada
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    Default Re: Need help with heavy mite load

    The OP is using 4 treatments at 4 day intervals which sounds good. My feeling that quitting after the fourth treatment is not a good policy if mite levels are still high. When you have the mites on the run keep hammering them; dont stop and allow them to catch their wind.

    Could the difference in apparent effectiveness be caused by drift into the nuc or low level robbing due to lower defenses?
    Frank

  6. #5
    Join Date
    Jan 2016
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    San Mateo
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    504

    Default Re: Need help with heavy mite load

    Quote Originally Posted by mhansman View Post
    ... I do it every 4 days for 4 times.

    I'm in California - still fairly warm and bees still bringing plenty pollen back to hive.

    Thoughts?
    Four times every four days is only thirteen days. Barely enough to expose the mites from worker brood, but too short for drone brood, which mites prefer.

    How big is the new hive? I'm in coastal San Mateo Co, have found that OAV series could only save hives in combination with splits/brood breaks.

    Local beekeepers swear by Apivar and formic acid products. Haven't been able to find forage-free 56 days for Apivar; and have ordered those Canadian FA pads from Mann Lake but they were obviously damaged: cracked and wet inner wrap.

  7. #6
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    Mar 2013
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    Seattle WA
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    Default Re: Need help with heavy mite load

    Quote Originally Posted by baybee View Post
    Four times every four days is only thirteen days. Barely enough to expose the mites from worker brood, but too short for drone brood, which mites prefer.
    In my area the bees stopped raising drones in July, as soon a the annual drought / dearth hits. I would think that in Cali, which gets hit with a drought every year as well, would have very few drone cells this time of year. My best guess is that the 4 treatments should have helped a lot. If not, drift is a major problem.

  8. #7
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    May 2008
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    Port Orange, Florida, USA
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    243

    Default Re: Need help with heavy mite load

    Four treatments four days apart doesn't even cover one brood cycle of a bee and is only 1 1/2 times the life cycle of a mite, two mite life cycles would be a minimum to expect any type of control. I would treat for at least six 4 day treatments and count the mite drop 24 hours after each treatment if you have the time. It's not that you are doing anything wrong you just need to do it longer to nail them.

  9. #8
    Join Date
    Apr 2018
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    Santa Cruz, CA, USA
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    19

    Default Re: Need help with heavy mite load

    Really appreciate this forum.

    The answer to how big is the hive - it's two medium boxes at this point. Still plenty of brood in it.

    I did purchase some Apivar from Mann Lake today and will plan on trying it when it arrives. I like the idea of 6 cycles of the OAV as well, or testing after.

    It'll be good to have a couple weapons in the tool box to get this hive through winter.

  10. #9
    Join Date
    Jan 2016
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    San Mateo
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    504

    Default Re: Need help with heavy mite load

    Quote Originally Posted by mhansman View Post
    ...I did purchase some Apivar from Mann Lake today and will plan on trying it when it arrives.
    ...
    I wish I could apply Apivar. Minimum application time for Apivar is 42 days, plus two extra weeks before supers are allowed back on -- this makes it eight weeks, meaning that supposedly any honey collected between today and, at best, Dec 11 will be contaminated with a synthetic acaricide.

    The eucalyptus globulus start blooming around Halloween, two weeks from now, which, depending on the weather, may mean nectar flow. There are lots of flower buds on local eucalipti.

  11. #10
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    Mar 2013
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    Seattle WA
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    Default Re: Need help with heavy mite load

    Quote Originally Posted by Beeboy01 View Post
    Four treatments four days apart doesn't even cover one brood cycle of a bee and is only 1 1/2 times the life cycle of a mite, two mite life cycles would be a minimum to expect any type of control. I would treat for at least six 4 day treatments and count the mite drop 24 hours after each treatment if you have the time. It's not that you are doing anything wrong you just need to do it longer to nail them.
    Beeboy, you need to check your math. 4 treatments cover a total of 12 days. you would be treating on days 1,5,9 and 12. Worker bee larvae are only under the cappings for 10 days. Uncapped brood still gets exposed to OAV. Drone brood is a different story but this time of year most area in the US do not have much drone brood so it should not be much of an issue.

  12. #11
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    Rutland County, Vermont,USA
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    Default Re: Need help with heavy mite load

    Quote Originally Posted by dudelt View Post
    Beeboy, you need to check your math. 4 treatments cover a total of 12 days. you would be treating on days 1,5,9 and 12. Worker bee larvae are only under the cappings for 10 days. Uncapped brood still gets exposed to OAV. Drone brood is a different story but this time of year most area in the US do not have much drone brood so it should not be much of an issue.
    I have always understood that OAV is only effective on phoretic mites. Thus the 7x3 or 5x4 treatment schedule. I have also noticed a creeping in recommended dosing. First 7x3, then 5x4 now 4x4. Granted, it may be called for in some cases, but now it seems as it is being adopted as normal treatment schedules. J

  13. #12
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    Default Re: Need help with heavy mite load

    This is the first I am hearing of a 4x4 OAV treatment which obviously does not cover the same number of days as the other two recommended schedules. However, the schedules themselves, while based on math, are still arbitrary. I would treat every 4-5 days until the mite drop from the last treatment was near 0 if my hive was heavily infested. Or, treat once to knock down the phoretic mites and go with the Apivar strips. I don't understand the logic of sacrificing the bees to mites in order to get a fall honey crop. J, if the OAV is not getting the job done, go with something that will, like Apivar. Then resume OAV as a control treatment. Unless you are TF and doing your part to "build a better bee", there is no reason for a hive to die from mites with the tools we have at our disposal.
    Thankfully, the bees are smarter than I am. They are doing well, in spite of my efforts to help them.

  14. #13
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    Algoma District Northern Ontario, Canada
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    Default Re: Need help with heavy mite load

    I think I commented that the 4 treatments every 4 days was good. I guess I was thinking of the 4 day interval part but not the lack of sufficient time to cover the whole term of capping, esp with drone brood. I believe I did say to continue treatments till no more mites fall. I am not fixated on exactly 5 days spacing and often vary from four to five days depending on weather and other interference. I really kick myself for losing ground if I have gaps of more than 5 days though.

    If you have a lot of surrounding bees that have high mite loads, you have to remember that in drift from them rather nullifies the exposure timing that only applies to the bees continually exposed to your timing controls.

    I am pretty fortunate in this regard by being quite isolated from other bees.
    Frank

  15. #14
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    May 2008
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    Port Orange, Florida, USA
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    Default Re: Need help with heavy mite load

    Dudeit, "you need to check your math. 4 treatments cover a total of 12 days. you would be treating on days 1,5,9 and 12. Worker bee larvae are only under the cappings for 10 days. Uncapped brood still gets exposed to OAV. Drone brood is a different story but this time of year most area in the US do not have much drone brood so it should not be much of an issue."
    I was referring to how long the OAV is effective in a hive which from my experience is four days. After treatment #4 at day 12 the OAV will still kill mites for four days which is a 16 day treatment. I ended up using a 4 day, four treatment plan on one hive that had a major infestation but found that the hive needed two more treatments to reduce the 24 hour mite drop to an acceptable level.

  16. #15
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    Seattle WA
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    Default Re: Need help with heavy mite load

    Beeboy, Thanks for the clarification. One of the issues with written words is that they can often be misunderstood. I have used the every 4th day treatment a couple of times due to scheduling problems and found it to work well.

    MHansman, one of the issues I see here on the forum is the level of reinfestation talked about in California, especially in the bay area. Retreatment is often needed regardless of the treatment used and staying on top of the problem is really hard. You treat and see thousands of dead mites and 2 weeks later your numbers are still extremely high. I am convinced that the "organic" lifestyle seen in the area encourages irresponsible treatment free beekeeping and the numbers of treatment free beeks in the area are causing issues for others. FYI, not all treatment free beeks are irresponsible. A lot are VERY responsible and really know what they are doing! I am fortunate, I don't have the mite pressures seen in other locations in my area.

  17. #16
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    Apr 2016
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    Rutland County, Vermont,USA
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    Default Re: Need help with heavy mite load

    Can someone point me to a study that confirms that OAV is effective on mites in uncapped cells? This is the first I have heard this is such an affirmative way. Perhaps it is my misunderstanding of terms. I was taught that OAV is only effective on phoretic mites. My understanding of the term "phoretic" is that the mite is being transported by the host. In my mind this means a hatched adult bee, not an egg or larvae. Have I misunderstood this for my whole 3 years in beekeeping? J

  18. #17
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    Apr 2017
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    Default Re: Need help with heavy mite load

    I would NOT use the Apivar.

    I'm also in Santa Cruz and we're about to hit a big bloom with the Eucalyptus that will bloom in the next couple of weeks. Anything collected from the bees for the next 8 weeks will be contaminated. I think you made the right choice by choosing OAV and I wouldn't give up on it yet.

    I once noticed my mite drops were nearly zero after an OAV treatment. I replaced my OA with a higher grade than just "wood bleach" and my mite counts were HUGE! I would first, buy a higher or newer grade of OA. I would also stick to your treatment plan, treating both hives at the same time and at night. This will make sure to treat all the bees in the hive as you're missing all those on the foragers during the day. 4 treatments 4 days apart should definitely knock them way down.

    Also make sure you have a mite board or some way of seeing the drop each treatment. I've even seen people slide white political sign board, cut to size, in through a solid bottom board after each treatment to see what falls on it for the next treatment 4 days later.

    Remember our climate is different than most. We're about to head into the best time of year for beekeeping while others are putting their hives away for winter.

  19. #18
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    May 2008
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    Port Orange, Florida, USA
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    Default Re: Need help with heavy mite load

    I'm targeting the mother or breeder female mite with the shorter treatments that is only phoretic for a short time as she moves from brood cell to brood cell. Mites either go directly onto the worker bee which is their phoretic phase and stay active for weeks on the bees or move to another brood cell within about 30 hours and repeat the breeding cycle, in other words short term phoretic. By treating every 4 days the OAV crystal levels are increase in the hive and interrupts the breeder mite cycle as well as knocking down the rest of the phoretic mites present on the bees. It's an idea I've been working on and has worked well on a heavily infested hive that I experimented on this year.
    i don't know of any studies that show that OAV is effective on the mites present in uncapped brood cells, from what I understand the breeder female crawls into the uncapped brood cell and hides at the bottom till the cell gets capped then it lays a male egg followed up by females eggs. There not much chance of a breeder mite getting exposed to OAV once it's in the brood cell. Exposing them to OAV when they move from brood cell to brood cell is the obvious solution to stopping the breeders and shorter times between treatments seem to have a lot of potential in doing this. I'll get down off the soap box, just don't like mites or small hive beetles.

  20. #19
    Join Date
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    Scott county, Arkansas, Usa
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    Default Re: Need help with heavy mite load

    To add to what Beeboy said, mites hide under the jelly after they enter the cell. They have a breathing tube that allows them to do so. I would assume this would take them out of reach of OAV.

    Alex
    Ten years of Beekeeping before varroa. Started again spring of 2014.

  21. #20
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    Default Re: Need help with heavy mite load

    Beeboy01: yes, what you just said is how I understand the mite cycle and OAV, but earlier you stated that "Uncapped brood still gets exposed to OAV" and I thought you took that into account with your 4x4 schedule which actually covers 13 days. J

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