Varroa Mites in Early Spring

By: Chari Elam

Here we go again! For all beekeepers, a scramble is about to ensue: What Varroa treatment should I use this year?

February and March (early spring) can be a really tough time of year for our bees. So much is going on. Populations are growing inside our hives, yet forage options aren’t there to support it. Caveat: when brood is building, so are Varroa mites. Population increase season means Varroa mite season.

What we learned from the 2024–25 bee collapse

As the results of the catastrophic bee losses are revealed, a great number of beekeepers have been left with more questions than answers.

The generalized results: High levels of viruses such as deformed wing virus (DWV-A and DWV-B) plus acute bee paralysis (results of Varroa mite infestations). To the average beekeeper this seems almost illogical since most of us are “on top of it,” managing mite loads regularly. Right?

Looking at the overall consensus of these studies, they reveal that Varroa mites are gaining resistance (in some areas) to at least one of the staple treatments in our arsenal, Apivar (Amitraz). But, at the risk of ruffling a few feathers, the product still has validity. Apivar is still considered a valid “quick kill” when high mite loads are present. Resistance occurs when any one product is overused or misused. The takeaway is to rotate treatment options every time, not just every so often. Also, remove the strips after a certain time, according to the instructions, to help prevent resistance in your area. In other words, follow the instructions to the letter!

When would I need a “quick kill” product?

Mite loads of over 3% are considered high. Depending on your testing method, this would warrant a quick kill.

•        Alcohol wash – More than 9 mites per 300 bees (3 mites per 100 bees)
•        Sugar roll – More than 6 mites per 300 bees (2 mites per 100 bees)
•        Stick board – More than 10–13 mites dropped in a 24-hour period (40 mites per 3 days)

Integrated pest management (IPM)

Such a long term for such an easy approach. In simple terms this means using mechanical methods like screen bottom boards, requeening each year, making splits to create a brood break, along with doing treatments when warranted. Basically, hit it from all directions.

Controlling Varroa mites doesn’t have to involve all synthetic miticides. If you manage your mite loads regularly, it’s easy to manage mites using the IPM method.

How? Test your mite loads monthly. This may sound like a lot, but trust me—it will pay off. Depending on how many hives you have, you do not have to test every hive in your beeyard.

Use this sliding scale:

•         1–10 hives: Test all of them
•         11–20 hives: If in the same beeyard, test at least half
•         Over 20 in the same beeyard: Test at least 30%, focusing on a percentage in each location.

Which product do I choose?

I feel the need to say, “Don’t overcomplicate this!” The basics still apply: time of year and temperature, equating to population stage (dormant, population increase, peak, or decline).

Early spring—and I mean early—can be a pivotal time. We are leaving the broodless or low-brood season when oxalic acid is most effective and entering the population-increase period. When this happens, take a breath, and think about the results you need to obtain. This is determined by your test results.

If an alcohol test in late February reveals a high mite load, you’ll need to get serious about your approach—meaning products previously discussed, such as Apivar, for a quick kill are suggested. Depending on your region, you may still be knee deep in snow in late February and not even able to test yet! Regardless of when you start testing, use the Honey Bee Health Coalition decision tool. I notice that some of the new treatments aren’t yet included in this decision tool, but don’t let that stop you from utilizing its content.

New products on the market

Products like VarroxSan™ have emerged and are very promising mite-treatment options utilizing oxalic acid in an easy-to-use delivery method (strips that lay over top bars). This product is applicable when OA is recommended as an option on the HBHC Decision Tool.

Another new product on the market is called Norroa™. This product is basically a “sterilizer” for Varroa mites. Genius, right?! However, it’s best applied anytime mite levels aren’t very high (< 2%) and honey supers are not on. That means it’s a great maintenance product before or after honey flow.

The bottom line

Don’t overthink your responsibility when it comes to treating Varroa mites. We all have mites in our hives. The only difference is how many.

• Treat according to:
•           Time of year
•           Mite load
•           Population
•          Temperature outside

Keeping that in mind, the rest is just a matter of choosing which is best for you.

Oh, in case I didn’t say it clearly, test! Testing is the only way to get to the right answers.