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Monitoring mites with a sugar shake

It seems that every beekeeping group has its own way to monitor Varroa mites. I keep hearing variations on the sugar shake (or sugar roll), the alcohol wash, and the soap bath. But one thing remains constant: most hobby beekeepers don’t want to kill bees in order to count mites.

The powdered sugar shake does not kill bees. The sugar-coated honey bees are easily added back to the hive and the sugar consumed. Both the alcohol wash and the soap bath give a slightly more accurate count, but both kill the bees. Soap and alcohol give more accurate results for two reasons: they better separate the mites from the bees and they allow an actual count of the bees in the sample instead of an estimate.

However, it is my opinion that beekeepers are more likely to monitor if they don’t have to kill bees in the process. I also believe that the easier it is to do, the more likely it is to happen. Furthermore, I don’t think the last scintilla of accuracy makes much difference. Your decision to treat or not treat will probably be unaffected by the one or two mites you missed.

If you are uncomfortable with the difference, you can try this at home: Do a sugar shake and count the mites. Next, use alcohol on the same group of bees and count the extra mites. In most cases, you will find that the sugar shake dislodged at least 90% of the mites.

If you want, you can assume you are getting 90% of the mites with your sugar shake, and then you can adjust the estimate by  dividing your count by 90%. For example, if your sugar roll yielded 8 mites, then 0.9χ = 8, so χ = 8.8 mites. Let’s call it 9. But do I think this is a necessary step? No.

In the interest of simplicity I have distilled a number of sources that describe how to do a sugar shake and tried to make it as easy as possible.

Simple Instructions for a Sugar Shake Test (Sugar Roll)

Equipment Needed:

  • A mason jar with a marking at the 1/2-cup level. Some mason jars come with embossed measurements, or you can draw a line with a marker.
  • A mason jar ring fitted with a round disk of #8 hardware cloth. This lid must fit on your mason jar.
  • Confectioner’s sugar (powdered sugar or icing sugar)
  • A spoon
  • A container for counting mites. It should be white or at least very light colored so the mites can be seen.
  • A bucket, bowl, feeder, Tupperware container, or something that you will shake your bees into.
  • A small amount of water

Prepare all this equipment in advance. If you use a 5-gallon bucket to catch the bees, you can put the rest of your equipment in there for transport. Once in the apiary, lay out your equipment.

Now, here are the steps:

  1. Remove 1 or 2 frames of bees from the brood nest. Ideally, these frames will contain open brood and nurse bees. Make sure the frames you shake do not include the queen.
  2. Shake the frames over your bucket. Don’t bang the frames, just shake.
  3. Take your bucket of bees, tap it so the bees collect on the bottom, and then pour them into your mason jar up to the 1/2-cup line. This will give you approximately 400* bees.
  4. Quickly screw on the modified lid.
  5. Pour the rest of the bees back in the hive.
  6. Spoon some confectioners sugar onto the mesh screen and work it through with your fingers.
  7. Shake the bees in the jar for about a minute to completely coat both bees and mites, using as much sugar as necessary.
  8. Invert the jar and shake it into your light-colored dish. Keep shaking until mites and sugar stop falling out.
  9. Add a small amount of water to your dish of mites. This dissolves the sugar and makes the mites easier to see.
  10. Count the mites.

This concludes the actual test. Next you will need to consult a chart in order to decide if you should treat for mites. Recommendations vary depending on the season and where you live. Also, recommendations may be given based on the number of mites per bee, in which case you will have to divide your mite count by the estimated number of bees in your sample.

None of the methods mentioned above—sugar, soap, or alcohol—count the mites under the brood caps, but most of the charts available take this into consideration. If you are uncertain, but sure to read the fine print.

Although this system is not perfect, it will give you a lot of information for a very small amount of effort. Give it a try and see how your mites are doing. One way or the other, you might be surprised.

Rusty
HoneyBeeSuite


*Estimates vary. According to Marla Spivak at the University of Minnesota, there are approximately 100 bees per fluid ounce.

Comments

Nick Holmes
Reply

Hi,
Do you have a reference you can point at about the calculation for working out infestation levels, the only ones I know about are for mite drop through the screen floor under normal activity.

Rusty
Reply

The University of Minnesota says this, “If you know how many bees were in your sample, you can estimate the number of mites per 100 bees. If there is brood in the colony when you sample, you should double this number to factor in the amount of mites in worker brood. For example, if there are 5 mites/100 bees, the total infestation is probably 10 mites/100 bees. If your colony has over 10-12 mites/100 bees, you should consider treatment.”

On the other hand, The University of Montana recommends treating if you get 5-9 mites from a sugar roll containing 250 bees. I assume they are doubling the number to account for brood, which would give you 10-18 mites. Dividing that by 2.5 gives you 4-7 mites/100 bees. Those are fairly inconsistent, so I hesitate to recommend one over the other.

Tom
Reply

Today I opened up one of my hives to remove the spent HopGuard strips and put the quilt box on for the winter. I was surprised to find a nest of ladybugs under the telescopic outer cover and the inner cover. Although I have been bitten by the orange ladybugs before, I doubt the ladybugs would attack the bees but I was wondering if they would eat the mites. I would guess their main reason for being there was to stay warm and dry but wouldn’t it be great if these are a natural predator of the varroa mites.

Nick Holmes
Reply

Ok thanks… gives me a start in terms of mites / role = infestation in hive. I should be able to extrapolate from that. Thanks 🙂

Robbin
Reply

Hi Rusty,

I didn’t want to use chemicals to treat, so I read & read to find the best way to treat for mites. So I settled on the wintergreen patty recipe you provided, sugar sprinkle, followed up with about 60 drops of peppermint oil mixed in about 2 pints or less of honey (theirs) in a baggie feeder. I also saturated strips of paper towels with a mixture of 1/2 cup corn oil and tea tree oil/peppermint oil/patchouli oil in a plastic condiment squeeze bottle, I used only 2 oils together. I laid the saturated 5×5 pieces of paper towels, 2 in each hive directly on the frames in the upper brood box, with the hopes they chew it up and get some oils. (I only overwinter with 2 deeps.) Oo I tucked them in with a candyboard, said a prayer and will check on them before deep winter sets in. This is just my second year so I’m still learning. I’m not a helicopter beekeeper. I’m pretty lazy, and I let the bees be bees. I don’t go down in brood frames and examine and I don’t cut things open or out. It’s mostly because I do more harm being inexperienced than any real help. I hate tearing up all their hard work. The only thing I will do in the spring is try a walkaway split on my two hives. They beat me to it last palm Sunday lol!!!

Mark Martin
Reply

Very good! I actually tried the sugar roll method for the first time this year and had 4 mites drop. Ideally I would have done a set of brood frames in the top and bottom box and maybe averaged them together but I ran out of daylight. Hopefully the bees will make it through the winter and I can see how many mites drop next year in the spring, summer and fall.

PS – I’m trying the pine shavings in my ventilation board this winter. I’m excited to see how it works! Thanks!

Rusty
Reply

Glen,

I’m not sure exactly what you are asking . . . why what? But powdered sugar is found to be an effective mite control if done on a regular weekly schedule. It only gets part of the mites (and none under the cappings) so it must be repeated often. The sugar shake test dislodges a greater number of mites because you use more sugar per bee and you shake until they drop off. If you are treating bees in a hive, the bees only get a light dusting and they are not shaken, so the mites are better able to hold on.

Glen B
Reply

Actually am trying to figure out if this could drive pollen mites off of mason bees. When I see a badly coated mason bee, (pink with mites), at this point I tend to kill it. I don’t have to do that too often, cause I am a pretty good manager of them, but it does happen. Trying to figure out other less brutal methods.

I’ll let you know.

Rusty
Reply

Glen,

What an interesting question. I haven’t seen mites on masons in the last few years, but next time I do I will catch the bee and see what happens.

Glen B
Reply

Hi Rusty –

Sent a responding note, but didn’t explicitly say that my WHY is, why does it work, not why should one do it? Maybe I should have said HOW.

Three notes where one ought to have been enough – had I read what I’d written. Never time to do it right, always time to do it over.

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