Acceptable #mites/ capped drone cell??

[Pooh]

I pulled a frame of emerging drone to dissect and check the mite load inside. I found on average 2 mites/ capped drone cell. This dropped to less than one (average) in nearly emerging drone cells.

Do I need to worry about this level? If so, what is the best method this time of year. I have a super on that they are filling but could pull off if have to for treatement.

It was pretty interesting to open up the cells and carefully check everything out with a hand lens. THanks, Pooh

[George Fergusson]

I pulled a frame of emerging drone to dissect and check the mite load inside. I found on average 2 mites/ capped drone cell. This dropped to less than one (average) in nearly emerging drone cells.

Do I need to worry about this level? If so, what is the best method this time of year. I have a super on that they are filling but could pull off if have to for treatement.

Yes, you need to worry about that level of infestation. I don't know how to correlate levels of drone brood infestation to total mite population, but my rule of thumb, adopted from someone who has a much better thumb than I do, is if 20% of your drone brood is infested, then you have a worrisome mite load that needs attention. 20% would be 2 infested cells out of 20, or 20 out of 100. Finding multiple- 2 or more mites in a drone cell- is indicative of a much higher level of infestation. From the sounds of it, nearly 100% of the brood you checked was infested? I'd call that serious.

What to do? First, I'd remove that entire frame of drone brood, freeze it for 24 hours to kill the brood (and mites) and then put it back in the hive. The bees will clean it out and reuse it, either for more drone brood, or honey.

I'd also carefully examine the other frames for symptoms of mite infestation- uncapped brood, dead and dying emerging bees, etc. With the mites piling into your drone brood, you may not be seeing overt symptoms of PMS in your hive yet, but that is likely to change later this season when the bees cut back on raising drones and the mites are left with only worker brood to infest.

As for additional treatment, that's kind of a personal choice. I'd consider either powdered sugar or oxalic acid, either vapor or drip, given the time of year and possible severity of your infestation. In any case, the first thing I'd do is start monitoring mite drop with a sticky board. If you don't count `em, you won't know how big a problem you have. I'm afraid you have a pretty big problem. Treating while there is brood in the hive is never as effective as one would like. A drastic measure but an effective one is to remove all capped brood and freeze it and then treat the bees to knock down the phoretic mites. But you really need to monitor your mite levels to see how big a problem you have.


It was pretty interesting to open up the cells and carefully check everything out with a hand lens. THanks, Pooh

Yup. It is :)

Do some drop counts. Let us know.

[Robert Brenchley]

If you have mites in every drone cell, you may be in for problems with queen mating. I've come across suggestions that parasitised drones may not be able to fly fast enough to catch a queen. I don't know whether there's anything in this, but goven wiodespread reports of problems with queen mating, it's a worrying thought. Does anyone know more?

[George Fergusson]

>Does anyone know more?

Mother nature tries Her best to keep queens from inbreeding by arranging for virgins and drones from an apiary to fly in different directions and different distances. Queens supposedly fly an average of 2 miles or more to a distant DCA to mate. Drones generally fly to the nearest DCA.

Someone's queens may be out-flying these drone, but not their own mothers.

[tecumseh]

I would go with george that two per drone cell suggest problems. the number also suggest that the varroa are likely moving to worker cells to find a location to multiply.

the first thing you may desire to do is to begin scratching drone brood (a capping scratcher works quite nicely).... after that some bioliogical/chemical intervention is likely necessary plus requeening if possible.

when I see varroa on most of the capped drones larvae I intrepret this to mean that hive has problem. those hives that have less problems typically have varroa in clusters but not on each and every drone larvae.