Below is an excellent article by David the Apiarist on understanding the varroa mite population cycle as relates to management of Varroa mites. Understanding the pest is key to maximizing the impact of the treatement. I’ve chosen to crosspost it on this date to benefit my readers in the Midlands of South Carolina as we enter the period of time when the presence of brood is at it’s yearly low. References to the Eagles and Don Henley are entertaining as well.
Why bother treating colonies in midwinter to reduce Varroa infestation? After all, you probably treated them with Apiguard or Apivar (or possibly even Apistan) in late summer or early autumn.
Is there any need to treat again in midwinter?
Yes. To cut a long story short, there are basically two reasons why a midwinter mite treatment almost always makes sense:
- Mites will be present. In addition, they’ll be present at a level higher than the minimum level achievable, particularly if you last treated your colonies in late summer, rather than early autumn.
- The majority of mites will be phoretic, rather than hiding away in sealed brood. They’re therefore easy to target.
I’ll deal with these in reverse order …
Read the full article at: Kick ’em when they’re down — The Apiarist
Beekeeping365 
His page won’t let me comment, but he says that wax cappings on the pull-out tray indicate “emerging brood”. When did brood start being capped with wax?
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Well, that’s something I never considered. I assumed it was wax albeit a bit travel stained. Your comment got me wondering so I got out my copy of Hive and Honey Bee 2015 Ed. to investigate. Dr. Stan Schneider writes in Chapter 4, page 80, “During the last larval stage, workers cap the cell with wax, and the larva spins a cocoon.” Later he writes, The adult chews through the wax capping and emerges from the cell.” I admit the color of brood cappings makes one think perhaps they are made of something other than wax like perhaps the cocoon itself. Or perhaps the wax is exceedingly thin. Which now has me wondering how the pupa breathes during its capped stage.
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This may sound as weird as I feel saying it, but I think that writer is dead wrong, even if he is a doctor. All larvae that I have ever observed spin their own cocoon, ants, wasps, moths, etc. Wax would be completely unnecessary and yes it would make respiration difficult.
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I’ll check a few other sources. I agree it defies logic.
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