Varroa mites have been the single greatest threat to modern beekeeping since their arrival in the United States in the 1980s. These tiny, blood-feeding parasites have devastated colonies across the country. In recent years, winter colony losses have hovered between 30 and 40 percent nationally, and in some regions, the numbers are worse. Some surveys estimate that over 40 percent of managed colonies are lost each year in the U.S., with varroa playing a central role. These mites weaken bees, transmit viruses, and compromise the structure of a healthy hive.
If you’re keeping bees and not monitoring for mites, you’re operating blind. Mite infestations almost never stay at zero. And once numbers rise past a certain point, you’re already too late. That’s why learning how to do a mite wash is one of the most important things you can do as a beekeeper.
Why Monitor Mite Levels at All?
There are a few core reasons why mite monitoring isn’t optional anymore.
First, you need to know your current mite load. Even if you don’t treat. Even if you think your bees are resistant. Even if you’ve never seen a mite in your life. You cannot observe mite infestations visually until the damage is already done.
Second, you need a baseline if you ever want to know whether your chosen treatment actually worked. It’s easy to feel confident after vaporizing with oxalic acid or applying a thymol-based treatment, but unless you do a before-and-after count, you’re guessing. Monitoring is the only way to verify efficacy. If you’re exploring treatment options, check here for additional info:
https://bestbeekeepinggear.com/varroa-mite-control/
And third, monitoring lets you make informed decisions about timing. If your mite count is already at 5 mites per 100 bees in mid-July, waiting another month could doom your colony. If your count is 0 or 1, you might hold off and avoid unnecessary intervention.
The Three Most Common Mite Wash Methods
There are three methods beekeepers use to perform a mite wash: alcohol wash, dish soap wash, and sugar shake. All three involve sampling a group of bees (usually around 300) and agitating them to dislodge mites for counting.
The alcohol wash is the gold standard for accuracy. It works by submerging the sample bees in alcohol and shaking the container to break the bond between mites and bee bodies. The mites are then counted in the liquid. This method is extremely reliable but has one drawback: it kills the bees. Also, if you’re buying high-proof alcohol every few weeks, the cost adds up.
The dish soap wash is a great alternative. It works the same way as alcohol but uses a small amount of dish soap in water. The soap helps to break the physical bond between the mites and the bees during agitation, and the rinse easily releases the mites for counting. It’s just as accurate as alcohol, far cheaper, and safer to store. For most hobbyists, this is the best option.
The third option is the sugar shake. It’s a non-lethal method where powdered sugar is used to coat the bees. After shaking, the mites fall off through a mesh screen. The bees are later released. This sounds like the more humane option, and in some cases, it probably is. But here’s the truth: the sugar shake is far less reliable. It misses a lot of mites, especially if humidity is high or the shaking isn’t vigorous enough. And let’s be honest. We used to joke about the bees we released from sugar shakes as having Shaken Bee Syndrome. They stumble around like they just got tossed in a dryer. They’ll survive, but the idea that it’s entirely stress-free isn’t accurate either.
So to sum it up: alcohol and dish soap are both effective. Sugar shake – not so much.
Getting the Right Bees for Sampling
The bees that you include in your sample need to be young nurse bees. These are the bees that have recently emerged from capped brood, and that’s where varroa mites reproduce. Foragers and older bees aren’t as good of candidates because it has been longer since they were in the cells where varroa mite reproduction takes place. If you want meaningful data, sample from nurse bees that are actively working on brood frames.
Method 1: The Shake-and-Scoop
This is the standard approach. Remove a brood frame from the hive and shake the bees into a clean tub or bin. Then scoop out half a cup (roughly 300 bees) using a measuring cup or the sample container from your mite wash kit. Pour them into your wash container and continue with your chosen method.
This works fine and gives you a clean sample, but it can be a bit jarring for the bees and a little awkward depending on your hive setup.
Method 2: The Scrape-and-Catch (My Method)
Here’s how I prefer to do it. Pull a nurse bee frame from the hive and hang it on a frame hanger. Spray the bees lightly with sugar syrup to keep them busy and less likely to try and fly. Then, with a gloved hand, scrape downward across the frame while lifting the wash container up until it meets your hand. Let the bees fall directly into the container until you have what looks like a full sample.
After the wash, physically count the number of bees that where in your sample. Once you’ve done this five or six times, you’ll develop a feel for how much of a scrape equals about 300 bees. A little more or a little less isn’t going to change your results in any meaningful way. The key is consistency and knowing your sample size well enough to calculate mite levels accurately.
Performing the Wash
Once your bees are in the container, it’s time to do the wash. For either method, you’ll want to have your wash liquid prepped ahead of time.
For an alcohol wash, use 70% isopropyl alcohol. You can also use rubbing alcohol or ethanol-based windshield washer fluid with a similar concentration. Avoid 90% or higher alcohol. It’s more expensive and won’t yield better results. Pre-fill your mite wash container with about half to three-quarters of a cup of alcohol before adding bees.
For the dish soap wash, mix 1 to 2 teaspoons of plain, unscented dish soap into 1 quart of water. This creates a light soapy solution that helps dislodge mites without creating foam that interferes with counting. You can pre-mix the solution in a jug and pour enough into your container to fully cover the bees before shaking.
Secure the lid, then shake the container vigorously for about 60 seconds. Let it settle, then count the mites that have fallen through the mesh and collected in the bottom.
Some people get oddly bent out of shape about the shaking step. They’ll say you should only swirl the liquid across the bees gently, claiming that it’s somehow more effective or less disruptive to the sample. I shake. Hard. I want the mites dislodged, and vigorous shaking seems to accomplish that reliably. If I’m going to kill 300 bees to get a count, I want that count to be accurate.
If you’re unsure whether your sample contains exactly 300 bees, take a moment to count or estimate post-wash. Then divide your mite count by the number of bees and multiply by 100 to get your mite load per 100 bees.
For example:
- 9 mites in a 300-bee sample = 3 mites per 100 bees
- 9 mites in a 250-bee sample = 3.6 mites per 100 bees
A few bees either way won’t skew your data much, but if you’re way off on your sample size, the numbers become misleading.
Here’s a general guide to interpreting results:
- 0–1 mites per 100 bees: no action needed
- 2–3 mites per 100 bees: monitor closely
- 3+ mites per 100 bees: consider treatment
- 5+ mites per 100 bees: urgent intervention needed
Why It’s Okay to Kill 300 Bees
This is where people get emotional, and I get it. You’re doing everything you can to take care of your bees, and now someone is telling you to kill 300 of them on purpose. But here’s the deal. This is not about the individuals. It’s about the colony as a whole.
A strong colony can have anywhere from 30,000 to 60,000 bees in peak season. Taking 300 bees is less than 1 percent. It’s like plucking three hairs from your head to run a lab test. You won’t notice, and the colony won’t either. Additionally, remember that a single queen can lay upwards of 2000 eggs per day, so even if she only lays half of that, add 300 to the normal daily rate of attrition in the hive, and it’s only about a half of a day’s work to replace the lost bees.
More importantly, bees don’t view their lives the way we do. Everything in the hive functions for the good of the whole. Foragers work themselves to death. Drones live only to mate and then die. Guard bees will throw themselves at intruders to defend the colony. The idea that a few hundred nurse bees would be unwilling to die to help the colony survive longer is disconnected from how bee society works.
It may be uncomfortable for us, but it’s absolutely in line with the nature of the bees. Mite washes save hives. They save thousands of bees by sacrificing a few. You’re not being cruel. You’re being responsible.
Final Thoughts
Mite washes should be part of every beekeeper’s management plan. They’re not hard, they’re not expensive, and they give you critical insight into the health of your hives. Whether you prefer alcohol, dish soap, or even powdered sugar, the key is to be consistent and honest with the results. Guesswork is what kills colonies. Measurement is what saves them.
So if you’ve been putting it off, now’s the time. Pick your method, get your container, take a sample, and find out where you stand. Your bees will thank you for it, whether they know it or not.