Overwintering Bees in the Observation Hive

     I have tried several times over the past few years to let the colony in the observation hive in the store try to overwinter. Both times it ended badly for the bees. I'm not sure why they have such difficulty surviving the winter in the observation hive.

Queen Nora the First, the reigning monarch of the observation hive

     First of all, the observation colony is always a relatively new split with a new queen so mites and other parasites haven't had as much time to build up to seriously harmful levels.  Secondly, I keep that part of the store at 70 degrees, mainly to keep my inventory of honey in a liquid state for a longer period of time.  I also keep pieces of styrofoam insulation covering the sides of the observation hive when I am not actually looking at them. I do that to make it easier for the bees to maintain an appropriate temperature for their brood. They incubate their brood at 92 degrees Fahrenheit, 22 degrees warmer then the ambient temperature of the store.  Thirdly, I give them lots of sugar syrup.  One colony dwindled away in January and another one survived until early February.  It seems really counter-intuitive to me that the bees would have such difficulty overwintering in the observation hive.  One would think overwintering inside the store would be the honeybee equivalent of living on easy street.

     I decided to try it a third time because the current colony occupying my observation hive seems a little different.  They did a much better job accumulating stores for the winter and the queen actually reduced the brood nest at the time of year when that behavior would be expected. They seemed like a worthy colony for another attempt.

The hive has collected a lot of glistening nectar/syrup. 

    I decided  I would try to do the normal fall medications that I do with my other colonies.  I fed them about a gallon of 2:1 sugar syrup medicated with fumagilin over a period of a month as a treatment for nosema.  I would have given twice that amount to a full size colony.  After that I have continued to keep them well supplied with 2:1 sugar syrup.

A few pieces of apilifeVar place in the vent hole

     I had observed only an occasional varroa mite on the bottom clean out board. That fact, along with the relative newness of the colony caused me to think varroa mite levels probably weren't very high.  I decided to treat the hive anyway using ApilifeVar, a mite treatment from Italy. It is basically a thin wafer of florist foam which has been impregnated with thymol, eucalyptus, and menthol. I have found it to be a fairly effective mite treatment and have used it off and on for about eight years.  Since it is a rather small colony, consisting of just 4 frames,  I used half the usual dosage. Since I didn't want to go to the trouble of taking the observation hive outside, I simply placed the medication in one of the upper vent holes on each side and covered it those vent holes with duct tape. This first mite treatment was done on October 8th.

A bit of duct tape to seal in the medication

     I checked the bottom clean out board this morning (October 16) and found about 20 dead mites.  It wasn't a huge amount, but it told me that there were more mites in the hive than I had suspected. Based on those results I thought I worthwhile to continue with a second treatment.   Since there is no drone brood in the colony, I'm going to call it good with the two varroa treatments, rather than the three treatments advised in the label instructions.  Normally I'm treating with ApilifeVar in late August or early September so there is often still drone brood in the hive.  There are some dead varroa mites below but they are a bit harder to spot in the photo. There is one located in almost the very center of the photo, the size of a pin head, shiny reddish-maroon.

The bottom clean out board on October 16