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

IPM 5.5 Fighting Varroa 5.5: Biotechnical Tactics II

Introduction 1 Drone Brood Management and Trap Combs 1 Powdered sugar dusting 4 The Oliver 15-second sugar dust method 6 Discussion 7 The one-two punch—30 seconds to knock out varroa! 7 My new website 8 References 8 Tactics: Biotechnical Methods II–The one-two punch Sixth in a series on Integrated Pest Management of varroa Note: this […]

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IPM 5 Fighting Varroa 5: Biotechnical Tactics I

(Photos to be added – check back) Fifth in a series on Integrated Pest Management of varroa In the “silver bullet” model, any mite kill less than 95% was considered ineffective. Unfortunately, the days of that kill rate are fading for most synthetic chemicals. It would be wise for beekeepers to consider an alternate model […]

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IPM 4 Fighting Varroa4: Reconnaissance Mite sampling methods and thresholds

© Randy Oliver 2006 Three strategies I’ve found that always fail when battling varroa are: 1. Denial—“I haven’t seen any mites, so my mite levels must be low.” 2. Wishful thinking—“I haven’t seen very many mites, so I’m hoping and praying that my bees will be OK.” 3. Blind faith—“I used the latest snake oil […]

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IPM 3 Fighting Varroa 3: Strategy – Understanding Varroa Population Dynamics

Fighting Varroa: Continued Strategy © Randy Oliver 2006 Joe Beekeeper typically has a gnawing feeling in his gut that the ways he’s been dealing with the varroa mite are starting to fail. I heard a complaint at a recent convention: “How long can we continue in a business where 30% of our assets die each […]

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IPM 2 Fighting Varroa 2: Choosing your Troops: Breeding Mite-Fighting Bees

Second in a series on Integrated Pest Management of varroa Originally published in ABJ, Jan. 2007 I got tired of getting my butt kicked by varroa. My first step in getting the upper hand on the mite was to forswear the coddling of wimpy bees with synthetic chemicals. This decision cost me dearly as colonies […]

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Oxalic Acid: Heat Vaporization and Other Methods: Part 2 of 2 Parts

Originally published ABJ Jan 2007 In my article last month, I detailed the use of the oxalic acid sugar syrup “dribble” for varroa control, with the consensus opinion being that the dribble method was both highly effective at killing mites in broodless colonies, as well as being safe for the beekeeper to handle. I’ve added […]

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IPM 1 Fighting Varroa 1: The Silver Bullet, or Brass Knuckles?

© Randy Oliver 2006, 2009 The varroa mite is the toughest challenge ever faced by American beekeepers. Our reaction to it reminds me of the five stages of dealing with trauma (greatly paraphrased from Kubler-Ross 1997): Stage 1: Denial (this isn’t happening to me! There can’t be mites on my bees.) Stage 2: Anger (You […]

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Oxalic Acid: Questions, Answers, and More Questions: Part 1 of 2 Parts

©Randy Oliver 2006 Why Oxalic Acid? European beekeepers, who have dealt with varroa much longer than we have, and who often face regulations that do not look favorably upon chemicals that may contaminate honey, noted that varroa is susceptible to organic acids–such as formic (in ants), acetic (vinegar), lactic (milk acid), citric (citrus fruits), and […]

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The Learning Curve – Part 2: Killing Mites without Killing Your Bees

Randy Oliver “U.S. beekeepers crossed the Rubicon of pesticide application when Varroa mites were introduced in the late 1980s. They literally “tore down the fence,” as one wag put it, quickly transforming themselves from anti-pesticide fundamentalists into willing pesticide applicators.”—Dr. Malcolm Sanford (2008). Those of us who remember the arrival of varroa, and the devastation […]

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The Learning Curve – Part 1: 2009 Progress Report

Randy Oliver Physicist Neils Bohr once quipped, “An expert is a person who has made all the mistakes that can be made in a very narrow field.” This definition clearly excludes me from being any sort of expert, since I exuberantly continue to make new mistakes in my own beekeeping adventures. It appears unlikely that, […]

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Powdered sugar dusting – sweet and safe, but does it really work? Part 3

By Randy Oliver Scientific inquiry can be exciting yet exasperating, satisfying yet frustrating! On these pages I share my own voyage of discovery, and enjoy the liberty of avoiding scientific formality. If one were to only read published papers, one might think that every experiment worked the first try, successfully answered a question, or made […]

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The Learning Curve – Part 5: The Future

Randy Oliver “I look to the future because that’s where I’m going to spend the rest of my life.” – George Burns Miticides in Development There are a number of new varroacides currently in development by various parties—some fairly close to release. Some are synthetics; some are naturally derived, such as propolis or plant extracts, […]

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The Learning Curve – Part 4: The Synthetic Miticides

Randy Oliver Paradise Lost The overall impact of the varroa mite upon beekeeping was recently brought home when I spent time with beekeepers on the Big Island of Hawai’i. Until recently, these lucky beekeepers enjoyed a true beekeeping paradise—abundant nectar and pollen flows, minimal agricultural pesticides, and best of all, no loathsome varroa or tracheal […]

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Powdered sugar dusting – sweet and safe, but does it really work? Part 2

By Randy Oliver One beauty of science is that it is anti-authoritarian. Physicist Lawrence Krauss put it well: “There are no scientific authorities. There are scientific experts, but there should be no authority figures whose statements are not subject to question by anyone….One of the greatest experiences scientists, indeed anyone, can have is to have […]

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The Learning Curve – Part 3: The Natural Miticides

I added a number of updates on May 2015, marking 15 years of successful commercial beekeeping in my operation without the use of synthetic miticides. Randy Oliver “It is not the strongest of the species that survives, nor the most intelligent that survives. It is the one that is the most adaptable to change”—Charles Darwin. […]

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