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Varroa Management

Allow me to start with an excellent assessment by Bee Culture’s Phil Craft (BC July 2015):

Perhaps beekeepers who have come to the craft in the last few decades aren’t aware of the effect varroa had when it first arrived on this continent and of how it earned its full name, Varroa destructor. Whatever the reason, every year, beekeepers all over the country lose colonies to mites and the viruses of which they are carriers, and they never know what hit them. They blame pesticides,or CCD, or habitat loss, and sometimes those really are causes, or at least significant factors. However, too, too often, the underlying cause is a lack of effective management, which allows a mite infestation to overwhelm a colony or weaken it to the point that it succumbs easily to other stressors. The most frustrating thing about these losses is that they don’t have to happen.

Watch Dennis vanEngelsdorp explain why mite management is critical for colony survival, and which methods work or don’t at https://www.youtube.com/watch?v=4bm3Y4t1NwQ


The Varroa Problem: Part 16b – Bee Drift and Mite Dispersal (cont.)

First published in: American Bee Journal, May 2018

Contents Bee Drift and Mite Dispersal (continued) 1 So why do colonies allow bees to drift in?. 1 The sheer numbers involved. 4 The amount of mite drift into other hives. 5 Collapse and Robbing. 7 What happens to all the mite-infested bees when a colony collapses?. 8 Swarms coming back to bite you in […]

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The Varroa Problem: Part 16a Bee Drift and Mite Dispersal

First published in: American Bee Journal, April 2018

Contents Bee Drift and Mite Dispersal 1 Dispersal of varroa. 2 Phoresy, grooming, and host preference by the mites. 3 The shifting of varroa’s preferred transport. 6 Our unnaturally close placement of hives in apiaries. 7 Measured rates of hive-to-hive worker and drone drift. 7 The Diffusion of Mites. 8 Are some hives more attractive […]

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Selective Breeding for Mite Resistance: 1000 hives, 100 hours

First published in: American Bee Journal, March 2018

Contents Quick summary. 1 First assessment—early July. 1 Breeder disappointment. 2 Second through fourth assessments. 3 The final tally. 3 The Cost of the selective breeding program.. 4 what’s next. 4 Control of matings. 5 Analysis of the late-season Failure to Maintain low mite levels. 5 Could the spikes have come from mite reproduction?. 11 […]

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How to perform an alcohol wash

If you prep correctly, it only takes a few minutes to determine the varroa infestation rate of a hive.  Here I show how to do it in under 4 minutes. View a video that my assistant Brooke Molina shot the other day with her cell phone:

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The Varroa Problem: Part 15 – Modeling the Effect of Mite Treatments

First published in: American Bee Journal, February 2018

Contents Early-season mite management. 2 Mid-season mite management. 4 Late-summer mite management. 4 A day-by-day model 5 The basics of oxalic vaporization. 6 The optimal interval for OA vaporization treatments. 9 Fall-winter mite management. 13 Acknowledgements. 13 Notes and Citations. 14   The Varroa Problem: Part 15 Modeling the Effect of Mite Treatments Randy Oliver […]

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Extended-Release Oxalic Acid Progress Report #3

First published in: American Bee Journal, January 2018

Extended-Release Oxalic Acid Progress Report #3 Randy Oliver ScientificBeekeeping.com First published in ABJ January 2018 As the synthetic miticides predictably lose their effectiveness across the world, beekeepers are turning more and more toward oxalic acid to control varroa. Unfortunately, oxalic is not a very efficacious treatment when there is brood present. To that end I […]

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The Varroa Problem: Part 14- Virus Dynamics and Treatments

First published in: American Bee Journal, January 2018

Contents The problem with waiting too late to treat. 1 Virus dynamics and miticides. 3 The question of timing. 3 the proportion of mites that are in the brood. 5 Efficacy of treatments. 8 The problem with the bombs. 8 Coming next. 10 Acknowledgements. 10 Notes and Citations. 10     The Varroa Problem: Part […]

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The Varroa Problem: Part 13 Using the Mite Model

First published in: American Bee Journal, December 2017

The Varroa Problem: Part 13 Using the Mite Model First published in ABJ December 2017 Randy Oliver ScientificBeekeeping.com It’s been nearly 25 years since I saw the first varroa mite in one of my hives, and it’s been a wild ride since then.  Not only for our bees, but also for the business of beekeeping, […]

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The Varroa Problem: Part 12- Building a Model

First published in: American Bee Journal, November 2017

The Varroa Problem: Part 12 Building a Model First published in ABJ November 2017 Randy Oliver ScientificBeekeeping.com      In my last article, I showed the basic math of varroa buildup during the period of broodrearing, and the subsequent decline of the mite population when no broodrearing was taking place.  My simple graphs were illustrative of […]

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Extended-Release Oxalic Acid Progress Report #2

First published in: American Bee Journal, October 2017

  Extended-release Oxalic Acid Progress Report #2 Randy Oliver ScientificBeekeeping.com First published in ABJ October 2017      There has been a huge amount of interest in the extended-release application of oxalic acid for controlling varroa.  I and my collaborators have been working hard to collect the data necessary get this treatment approved for use by […]

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The Varroa Problem: Part 11- The Math of the Mite

First published in: American Bee Journal, October 2017

The Varroa Problem: Part 11 The Math of the Mite Randy Oliver ScientificBeekeeping.com First published in ABJ October 2017      I’ve previously written about how the seasonal buildup and decline of the honey bee colony is a function of the birth and death rates of the workers [[1]].  Varroa follows a similar buildup and decline […]

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The Varroa Problem: Part 10-Smokin’-Hot Mite Washin’

First published in: American Bee Journal, September 2017 - this version updated

The Varroa Problem: Part 10 Smokin’-Hot Mite Washin’ Randy Oliver ScientificBeekeeping.com First published in ABJ September 2017      If you had asked me even a month ago as to how many of your hives to sample for varroa, I’d have suggested using Katie Lee’s plan of 8 hives per apiary [[1]] (in truth, we’ve rarely […]

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The Varroa Problem: Part 9- Knowing Thine Enemy

First published in: American Bee Journal, August 2017

The Varroa Problem: Part 9 Knowing Thine Enemy First published in ABJ August 2017 Updated Dec 2021 Randy Oliver ScientificBeekeeping.com      “If you know the enemy and know yourself, you need not fear the result of a hundred battles”– Sun Tzu.  We are all beekeepers; we are also all varroa keepers (some of us better […]

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The Varroa Problem: Part 8 – Regulatory Cascades, Varroa Tolerance, and a Moon Shot

First published in: American Bee Journal, June 2017

The Varroa Problem: Part 8 Regulatory Cascades, Varroa Tolerance, and a Moon Shot Randy Oliver ScientificBeekeeping.com First published in ABJ June 2017      In writing this series, I skipped ahead over some details so that I could publish my suggestions for setting up a breeding program for mite resistance in time for this season’s queen […]

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The Varroa Problem: Part 7- Walking the Walk

First published in: American Bee Journal, May 2017

The Varroa Problem: Part 7 Walking the Walk Randy Oliver ScientificBeekeeping.com First published in ABJ May 2017      I’m not one to tell any beekeeper what they “should” be doing—it’s up to nature, the market, personal preference, and history to determine what works.  In my last two articles, I’ve discussed ways to go about breeding […]

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