Comparing Varroa Mite Treatments (What Beekeepers Use)

Updated on September 11th, 2022

Varroa mite infestation is nearly universal in honey bee colonies and represents one of the biggest threats to any colony’s survival. Beekeepers can choose from a variety of miticides (synthetic or organic chemicals) designed to mitigate the impact of varroa.

Comparing varroa mite treatments among beekeepers we polled, the most popular and effective treatment against varroa mites is oxalic acid. Another organic substance, formic acid (sold as Mite Away Quick Strips® or Formic Pro®) and Apivar®, a synthetic miticide, were 2nd and 3rd, respectively.

The vast majority of 178 beekeepers surveyed used multiple miticides, a widely accepted practice to avoid developing resistance to one chemical. Many also used non-chemical procedures as part of an integrated pest management system.

Miticides are pesticides specifically designed to target mites but not honey bees.

Beekeepers also told us what methods they prefer for checking infestation levels and other information.

In this article we will provide the results of our poll.

What Are Varroa Mites?

Varroa destructor mites are parasites that attach themselves to honey bee brood and adult bees.

Varroa mites feed on the host leading to varroosis, a parasitic disease. Varroosis weakens the bee’s immune system making it more susceptible to other diseases and viruses. Varroa aid the spread of disease as they move around the colony.

Varroa mites are found in virtually all honey bee colonies and reproductive growth is exponential. Left unchecked, varroa mites and the viruses they spread will eventually cause a colony to collapse.

It is extremely difficult, if not impossible, to eradicate varroa from honey bee colonies. Most beekeepers work to control their population and limit the damage they cause.

The 2018 NYS Beekeeper Tech Team Report (available here) says that 61% of colonies sampled indicated a mite infestation level that requires “immediate treatment to prevent colony death”. It also says, “Varroa mite levels are a significant predictor of winter loss in New York State.” In the 2016 report, the survey sample indicated 90% of colonies had Varroa. The presence of Varroa is nearly universal among bee colonies.

Our article Varroa Mites: A Complete Treatment Guide provides much greater detail about the varroa destructor mite, methods of testing the level of infestation and various ways to mitigate its impact on your hives.

About Our Varroa Mite Treatment Poll

Varroa mitigation is a popular, and occasionally controversial, beekeeping topic.

A lot has been written on what beekeepers can or “should” do to mitigate varroa. We decided to ask beekeepers in a number of Facebook beekeeping groups to find out what they actually ARE DOING.

While we received 178 responses, this is not a scientific study.

Not surprisingly, respondents to our survey were overwhelmingly U.S. based. Canada and the UK were next and a number of other countries had one response.

The U.S. responses came from 37 states, led by Maine (10.2%) and New York (8.2%).

Beekeeper Experience

Respondents to our questions had a wide variety of beekeeping experience, both in terms of years of beekeeping and the number of hives managed.

Do Beekeepers Use Chemicals To Control Varroa Mites?

Properly used chemicals are very effective in controlling varroa populations. Treatments are administered in ways designed to kill the mites but not the bees. However, the bees may have other reactions (besides death) to the treatments.

I think every beekeeper would prefer to manage hives chemical-free. In fact, some beekeepers are resolutely “treatment-free” avoiding all chemicals and even some non-chemical interference in the business of their honey bees.

We did not put our survey in a Facebook treatment-free beekeeping group as any discussion of treatments is forbidden. Despite that, several respondents indicated that they do not use any chemicals to treat varroa mites.

See our article What Is Treatment-Free Beekeeping? (A Controversial Topic) for more information.

Nearly 90% of those surveyed said they use chemical treatments to control varroa mites. Only 10% do not use chemicals.

How Do Beekeepers Decide When To Treat For Varroa?

Beekeeping guides typically advise chemically treating hives only when varroa mite infestation exceeds certain thresholds. Doing so limits the bees’ exposure to the chemicals and reduces chemical build-up in wax and food stores, including honey.

However, the efficacy of many chemicals is affected by variables such as the temperature, existence of brood, or if there is honey flow.

We have often treated our hives based on the calendar rather than mite counts because of these limitations. We wondered if we were alone.

We are clearly not alone.

Only 17.5% of respondents base their decision to treat for varroa solely on mite counts.

Over 82% use the calendar for at least some of their treatment decisions.

We suspect the primary driver of calendar treatments is the strong desire to treat just before winter. However, our survey did not address this question.

Treating New Bee Packages And Nucs

Newly purchased bees, particularly those from online suppliers, often come from large commercial bee operations and may have varroa mites. Even bees from reputable local beekeepers may arrive with some varroa.

I’ve seen recommendations to mist new bees with a mix of oxalic acid and sugar water prior to installing them in the hive. We have never done that.

It turns out that a majority of respondents do not treat newly arrived bees as standard procedure. However, a significant minority do treat newly acquired bees.

How Do You Determine Mite Counts?

These methods are discussed in detail in our varroa mite treatment guide.

A sizable majority or respondents used either the alcohol/soap wash or the powdered sugar roll to count mites. These are considered the most reliable methods. However, many respondents indicated that they use multiple methods for monitoring mites (thus, numbers exceed 100%).

What Chemical Treatments Do You Use For Varroa Mites?

Beekeepers have a choice of synthetic and natural miticides.

Synthetic miticides are man-made compounds not ordinarily found in nature; natural ones use organic acids or essential oils.

Do not be lulled into a false sense of safety by the word “natural”. Some of these materials can be harmful if not used properly. For example, oxalic acid, while a naturally occurring substance, can be very harmful if you inhale the vapors. Use caution with all these products.

Oxalic acid and formic acid are two very effective organic compounds used as miticides.

Popular Varroa Mite Treatment Options

Common varroa mite treatments are compared in the table below. The information is intended as a general guideline. CAREFULLY READ ALL INSTRUCTIONS AND WARNINGS INCLUDED WITH EACH PRODUCT, ESPECIALLY REGARDING THE USE OF PROTECTIVE EQUIPMENT.

Treatments Used By Beekeepers

Virtually all respondents indicated the use of multiple chemical treatments. This is recommended practice to reduce varroa resistance to any one treatment. It is most likely driven by timing issues related to temperature and hive conditions. (And totals exceed 100%.)

Which Miticide Is Most Or Least Effective In Controlling Varroa Mites?

What Non-Chemical Methods Do You Use To Control Varroa Mites?

Chemical treatment is generally considered the most effective method of controlling varroa. However, beekeepers often use non-chemical methods as additional steps to reduce varroa numbers.

Varroa mites reproduce more effectively in drone brood’s larger cells. Many of these non-chemical procedures involve disrupting the growth of the drone population inhibiting varroa reproduction.

A high percentage of respondents indicated the use of screened bottom boards. It is possible that many of these beekeepers use screened bottom boards for reasons unrelated to varroa so I am not sure it’s a meaningful statistic.

This is another area where beekeepers may employ multiple tactics so totals exceed 100%.

Varroa Mites And Winter Colony Losses

Getting colonies through winter is one of the most important tasks in beekeeping. We asked beekeepers about their results over the past two winters.

The survival rate breakdown could have been more precise. While over half had a survival rate above 75%, a substantial number (24.2%) were below 50% survival. A large percentage attribute their survival rate significantly to varroa control.

Conclusion

Beekeeping advice includes a lot of information about what you can do and what you should do when it comes to varroa mites.