WINTERING HONEY BEES
by George Brezina, West Québec, Canada
- Spring development
- Cost and labour
EVALUATION OF WINTERING METHODS:
Average winter loss (include queenless & weak colonies to be united):
- 0 to 5% very good
- 10% expected (Québec)
- Wintering cannot be taken out of context of year round management
- Wintering method must have the capacity to withstand extreme weather conditions in exceptional years
WINTER CLUSTER = ball of bees keeping in the heat
- outer layers - insulation (temp. above 10 0C / 0F)
- inner cluster - heat production (by shivering flight muscles; energy of 20 40W light bulb; temp. 20-360C / 68-960F)
Open cluster will form at outside temp. 5-100C / 4O-5O0F; it will close from the top and tighten with dropping temperatures.
Input: honey and oxygen
Output: heat, water, and carbon dioxide
- large: smaller surface relative to volume (favorable to withstand extreme weather conditions) – colony may eat all the stores and die of starvation
- small: may not be able to generate the heat to move to the stores – colony may die of starvation with honey left
Weaker colony - sometimes better chances to survive long winter but less likely to produce honey - do not winter it.
NUC - winter on top of another colony
- late winter, sunny days
- ashes or shavings may be spread on snow to reduce losses
With no disturbance and cool temperatures bees may go over 5 months without flight.
If fecal material in rectum reaches about 1/2 weight of the bee - it will defecate inside the hive.
- quantity - determined by strength of the colony, location, wintering method
- count min. 18kg / 4Olbs of sugar per hive or leave more honey and feed less
- quality - indigestible matter will cause dysentery
- feed only proven mixtures e.g.
white sugar : water = 2 : 1 (or 3 : 2) by weight
(1/2l of vinegar per 10 kg of sugar against nosema)
- timing - feed early (start by September 10)
- supplement if needed (in October) or leave sugar candy in top feeder
Compare other methods of local beekeepers.
- major cause of winter losses
- dead bees with heads inside the cells
(almost no bees and left-over honey - likely a varroa mite kill)
Two critical periods:
- late fall (October, November)
some years colonies may consume a substantial part of winter stores
- early spring (late February, March)
- loss of the best (strongest) hives
- feed (honey comb or creamed honey) if out of stores (heft the hive to check)
- do not open hive in full sun
- open for less than 1 min . (-50C / 230F is OK)
- strain: best is a proven local queen or a queen from harsher environment
age: young— less risk of loss (new queen or from last year)
Important: laying queen in July, August (eggs for winter bee population)
- feed wet sugar during inclement weather
(e.g. On December 21/1993 temp. dropped to -300C (-220F) and stayed in -200C to -300C (-40F to -220F) range, often dropping to -400C (-400F ) with an extreme of -480C (-550F). This lasted till February 15/1994. A strong colony would survive this with no protection but run out of stores at the end of February. )
- increased consumption
- bees falling off the cluster
- danger of starvation
- cluster may break
- high consumption
- temperature drop may catch bees away from the cluster
- condensation and ice formation
- molded frames
- heat loss (increased conductivity of air)
- full width of lower entrance
(clean if plugged with ice, dead bees – snow is OK) or
- upper entrance (notch in the rim of inner cover)
- insulation (reduces condensation)
permeable packing material (metal cover is a major source of condensation)
- protection from ground moisture (tar paper)
- overhang (tar paper under top cover)
- absorbent materials (shavings in top feeder, newspaper)
- heat loss
- increased condensation
- protected location
- wind fence
(rodents, hive inspections, ice removal, branches hitting the hive …)
- cluster looses temperature (at 180C / 640F it looses ability to generate heat)
- increased consumption, loss of bees
- provincial /state apiarist may provide guidelines
CONFIGURATION OF THE HIVE
- larger honey crop (honey super above the brood chamber is extracted)
- less room relative to hive population (favorable environmental conditions)
- possibility of insufficient empty comb space to form a tight cluster
- higher risk of insufficient stores
- potentially a superior configuration (with adequate wintering methods)
- top box full with capped honey and pollen
- bottom box partly empty
- common configuration for outside wintering (Ontario / Quebec)
- space for larger stores
- larger clean up job of a dead colony in spring
Organize hive before fall feeding:
- remove queen excluder
- remove frames that are not built
- move some pollen comb up
- cellars (ventilation essential!)
- refrigerated /ventilated buildings (e.g. a converted hot room)
- conditions: 30C/380F, 25ft3 per hive, darkness
- feeding: 30 — 40 lbs of sugar per hive
- well researched and tested – Quebec Ministry of Agriculture
- cold spell in spring (after the hives have been moved out) may set them back
- used by some large beekeepers in Montreal area
- stronger colonies in spring
- lower cost
- commonly used in Eastern Ontario / West Quebec
- Adequate protection
- Ease of access to the hive/replacement (spring inspection, feeding, medication)
- pallet of 4
- stacking on top
- added protection at no cost
- more work
- may not provide for easy access
Examples of Wrapping Methods:
BLACK CARTON (bottom waxed)
- standard method in Eastern Ontario, West Québec
- quick and easy installation
- air space between the hive and the carton reduces heat loss by conduction
- allows for the hive to be reheated by sun
- may be marginal in exposed locations
- preferably use with additional top insulation (e.g. 3" of polystyrene on inner cover)
- tar paper on top of the carton box (under the outer cover) may provide overhang
- supplier: Benson Bee Supplies Ltd.( 613-821-2797 / 1-800-214-7366 / fax: 613-821-2621)
- traditionally wood (or particle board), plywood platform and cover
- filled with shavings, fiberglass etc.
- pipe for top ventilation or not insulated front side
- mouse screen
- lightweight case may be constructed from an insulation board and used in a similar way as slip-over carton
- good results
TAR PAPER WRAP
- by itself may not be sufficient
- may be used over fiberglass or straw insulation
- benefits of over-insulating are questionable
- may accumulate moisture
- southern side may be left uninsulated (only wrapped)
- may not provide for easy access to the hive
BURIED UNDER THE SNOW
- best in combination with some wrapping
- permeable insulation, total draft protection
- will even temperature fluctuations
- low honey consumption
- possible delayed spring build up
BEE-HOUSE / PERMANENTLY INSULATED HIVES
- used in parts of Europe
- non-standard equipment
QUESTIONS and ANSWERS:
- When to remove the winter packing?
The hive protection is more important in spring than in winter. A cold spell
will chill the brood and set the hive back. In our climate wait till the middle
of May or later - not before the tomatoes are planted out.
- When to wrap the hives for winter?
Not too early. Cool hive will cease rearing brood and decrease consumption.
In West Quebec it may be done in the first week of November (before the deep
frost or heavy snowfall).
- Is the upper entrance essential in winter?
It depends on the wintering method. Personally, I had better experience with
full width of bottom entrance and no upper entrance.
- Is it necessary to reduce the bottom entrance?
No. The primary reason for entrance reduction is the defense against robbing.
Reduction of the bottom entrance may help to reduce the heat loss if the upper
entrance is used.
- How to protect the hive in winter against rodents?
Several methods exist. For example the height of the bottom entrance may be
lowered to the size of the bee space using a metal strip. Metal screen (1/4")
can be used. Care must be taken that the entrance will not get blocked by dead
bees / ice.
les abeilles dans le Nord
A venir bientot.