The Beekeeper’s Companion Since 1861

Letters to the Editor

Letters to the Editor – June 2017

- June 1, 2017 - (excerpt)

Pollen Atlas

With the honey flow about to begin, I am again looking at the pollen my bees are gathering, to see which flowers they are visiting. Here is the biggest problem in pollen identification: I have a pollen pellet smeared onto a microscope slide. I can go to atlases on the internet, but then have to search entry-by-entry to find a photo/diagram that matches my pollen. This is VERY time consuming.

Now, a Beekeeper’s Wife, Linda Lathrop of Laclede County in Missouri, a graduate botanist, has compiled an Excel spreadsheet of over 250 pollens, which has been installed on our club website. and

The beauty of her work is that the file is sortable by the pollen characteristics, so I only have to look individually at a few entries, instead of all 250.

In addition to the spread sheet, there are individual microscope photos of the pollen, some 450 photos in all, which is too much data for our club website to handle. I have these photos on disk and on thumb drive.

My problem is how to get these photos into the public domain, so everyone can have access to them. Who would like to publish these photos, with the spreadsheet, on their web site? Which university has a department that would do this? What bee research lab is willing to make this material public?

Linda wants to have this data used by all interested parties – she did not do the project just to sit on the results! Maybe someone would like to make it all into an e-book, and sell it?

If anyone has ideas, please get in touch with me, 608-244-5094.

Jeanne Hansen
Madison, WI


Winterizing the Hive

How much is enough?

Keeping honey bee colonies alive in winter is always a concern for northern beekeepers. We know bee colonies adapt to cold weather by clustering and eating honey to produce heat. Bees are in total cluster mode at around 41°F. Below this point, individual bees separated from the cluster become sluggish and then fall into torpor, then a chilly coma before dying of hypothermia; only the whole cluster can move inside the hive to cover the receding food stores. At temperatures around 20°F, the cluster becomes motionless, surviving on the amount of honey it covers, and waits for an adequate rise in the temperature to be able to move again. If a warming spell does not occur in time, the colony starves while there is still food inside the hive. The extremely low temperature of about −40°F kills the colony, no matter how much honey is being consumed. A weak (relatively less populated) colony may be killed at a higher temperature because it is unable to generate enough heat to save itself. Hardy honey bee stocks, such as Russians, Carniolans or others, survive better in colder climates because their metabolic rate gets reduced, requiring less honey consumption.

Northern beekeepers prepare their hives to conserve the heat produced by the bees by minimizing the loss of heat that dissipates from the cluster. They use windbreaks, reduce hive entrances, and apply insulating materials. They also expose their hives to direct sun light to get the heat needed for the cluster to move again towards new food areas in the comb. Some beekeepers, instead, move their hives into unheated barns, garages or into buildings where the temperature is set to be slightly lower than 41°F, just to keep the cluster able to move (A well insulated hive in the shade, in winter, is in a worse predicament than a barely protected one that is directly sun exposed).

The use of “Solar Hives” further increase the heat gained from the sun. (See ABJ, July 2014, Letters to the Editor, “Playing with the Winter Sun”) Solar hives appear to have risks: They provide more heat than what is needed by the bees for the time of the year. What good is there in warming the interior of the hive to be above 41°F when it is too cold for the bees to fly out and there is no food available outside to bring back? Solar hives also cause tremendous fluctuations in temperature within a very short period, from quite high levels during the sunny peak hours to a very low levels in late night hours. Plant buds may be damaged with the wide changes in temperature. Bees could also be negatively affected. I also suspect that solar hives may induce the colony to vigorously start raising brood earlier than usual, consuming all the beebread much sooner than when natural pollen resources become available. Having the hive exposed to the winter sun is, likely, sufficient and safe in my area.

I am now experimenting with “ground heat” to help honey bee colonies better survive the Northern winters.

The “ground heated hive” is a version of the old cold storage used by farmers to protect their produce.

Here’s my makeshift model: (my enthusiasm makes it look practical and easy)

  • Place two 48” x 40” pallets, one on top of the other, on a flat ground surface;
  • Place a sheet of plywood over the top pallet;
  • Place two inch thick Styrofoam board over the plywood;
  • Surround the pallets with bales of hay and large bags with dry leaves over the Styrofoam;
  • Cover it all with a tarp or a plastic sheet.
  • In the center of this pile, or dome, insert an empty hive deeper with its open bottom connected with the space formed by the pallets, functioning as a chimney.
  • On top of this “chimney”, place a queen excluder to serve as a mouse barrier. A slit on the frame of the queen excluder serves as a bee entrance (we could use a shim).
  • The hive proper, wrapped with roofing paper and with 2” Styrofoam under the outer cover, is finally placed above the queen excluder or the shim. (In the experiment, the hives have no bees and no frames with food).
  • I made two of these arrangements, side by side: one is on a flat ground surface, with one hive, the other, with two hives, is over a pit. The pit area is slightly shorter than the pallets, and is 18” deep, with its bottom closer to the local frost line or freezing line (32°F). (In much colder regions, the pit would likely be deeper).

This past winter (2016-17) was mild. The winter before was considered one of the coldest in record here in my area, with temperatures dropping to negative numbers, twice at −12°F.


I expected that the hives placed over the pit would be much warmer than the hives placed on the flat ground. However, the hives placed over the pit were never more than 3°F. The max temperature inside the three hives, at the warmest time of the day, was about the same. It was also equal inside …