Varroa Mites

Varroa mites and the diseases they carry represent the single biggest challenge facing honey bees in most areas of the world. In Utah, the vast majority of hive deaths are due to Varroa mite infestations that have been poorly managed. Proper Varroa mite management should be the top priority for beekeepers large and small. It is imperative that beekeepers regularly monitor for this parasite and treat their colonies with an effective Varroacide when mite levels are too high.

UDAF recommends that all beekeepers read the Honey Bee Health Coalition’s “Tools for Varroa Management” guide.



Monitoring Varroa Mite Populations

The first step in effective Varroa mite management is regular measurement of mite loads within colonies. UDAF recommends that beekeepers sample their apiaries for mites at least once a month throughout the beekeeping season. A healthy mite level is no higher than 2% at any point in the beekeeping season; this translates to 3-4 mites per ½ cup of bees measured. If at any point in the season the mite levels are at or higher than 2%, treatment is highly recommended. If you need a guide on how best to measure your mites please consult this guide:

Varroa Mite Measurement Fact Sheet

As you can see in the graph below mite levels in Utah start to become unacceptably high in August, peak in October and then fall in November. The November drop in mite levels is likely due in large part to colonies with high mite levels dying off in late October/November. While beekeepers should always be vigilant, extra care needs to be taken August through November to ensure that colonies mite loads are not above 2%.




Treatment Options

When Varroa mite levels are too high treatment is necessary to prevent colony loss; organic options are available. If you are unsure what treatment is best, consult the decision tool below:

Treatment Decision Tool

Be sure to read and follow the label on any treatment that you use; it’s the law. Further, improper application may cause a treatment to be ineffective or cause harm to the bees.