CIS 538 rev. Part 2

Winter Management

Winter management is an important part of producing good bees. Advantages and disadvantages of the following methods are presented in order of preference:
  1. Place bees in a cold storage room. 
  2. Move bees to a shed or barn.
  3. Leave bees in the field.

 

I. Place bees in a cold storage room at 34-38F and 50 percent relative humidity.

Advantages:

  1. Temperatures maintained at < 40F prevent damage from nest-destroying insects; 50 percent relative humidity inhibits mold growth but prevents the cells from drying out.
  2. Nest materials can be inspected and evaluated for nest-destroying pests, empty cells, etc.
  3. Bee emergence can be more easily synchronized with alfalfa bloom by incubation after cold storage. Thus, bees are available when they are needed.
  4. Reduce chance of theft.
  5. Nesting material from which the bees have been extracted can be sterilized for recycling.
  6. Maintenance, cleaning and sterilization of domiciles can be accomplished.
  7. Prevents fall buildup of predators and nest-destroying insects.
  8. Bees are less likely to use up energy reserves in warm fall weather, so they are more likely to emerge in the spring.  

Disadvantages:

  1. The cost of moving bees and storing them.
  2. Mechanical failure may permit relative humidity to rise beyond safe limits (70 percent) stimulating mold growth and causing bee mortality. When the temperature rises to 40F, nest-destroying insects become active; 110F will kill the larvae in the cells.
  3. If boards are stacked too close to allow good air circulation, temperatures in boards may rise above air temperature due to bee metabolism, and allow predators to develop.
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II. Move bees to a shed or barn.

Advantages:

  1. Nest materials can be inspected and evaluated more easily for living larvae, nest-destroying pests, dead cells, etc.
  2. Bees begin to emerge about the time alfalfa normally starts to bloom if they are placed in field shelters about 40 days before bloom.
  3. Maintenance, cleaning and sterilization of domiciles can be accomplished.

Disadvantages:

  1. Bee emergence may not coincide with alfalfa bloom when the bloom is delayed by cultural practices or weather.
  2. Bees emerge over an extended period of time from June until August. Too few bees may be active when the maximum bloom is present.
  3. The cost of moving bees and storing them.
  4. The concentration of nest materials in storage may promote the spread of nest-destroying insects from infested nests.
  5. Lack of temperature control encourages nest-destroying insects which are increasingly more active as temperatures rise above 40F.
  6. Lack of temperature control may cause some bees to use up energy reserves during the winter so they are not successful in emerging in the spring.  
  7. Higher risk of rodent and/or bird damage.
  8. Increased risk of fire or loss due to theft.
  9. If boards are stacked too close to allow good air circulation, temperatures in boards may rise above air temperature due to bee metabolism, and allow predators to develop.
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III. Leave bees in the field.

Advantages:

  1. Saves the cost of moving bees and storing them.
  2. Bees will overwinter in most areas if protected from direct exposure to the elements.
  3. Bees will begin emerging about the time alfalfa normally starts to bloom in the spring.

Disadvantages:

  1. Prolonged exposure to temperatures below -20F may kill some bees.
  2. Bee emergence may not coincide with alfalfa bloom when the bloom is delayed by cultural practices or weather.
  3. Bees emerge over an extended period of time from June until August and therefore too few bees may be active when the maximum bloom is present.
  4. Lack of temperature control encourages nest-destroying insects which are increasingly more active as temperatures rise above 40F.
  5. Lack of temperature control may cause some bees to use up energy reserves during the winter so they are not successful in emerging in the spring.  
  6. This practice presents the highest risk of loss from theft.
  7. Rodent and/or bird damage may occur.
  8. Domiciles cannot be easily cleaned and sanitized for chalkbrood and nest-destroying insect control.
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Further discussion of Fall and winter management 
If you have comments, corrections, or additions to the information provided in this document, contact Karen.
CIS 538 Contents:
INTRODUCTION
WINTER 
SPRING 
SUMMER 
FALL
OTHER 
Phase out
Shelter Size and Design
Nesting Material
Buying bees and/or loose cells
Sanitation
Avoiding theft; Purchase precautions.
ABOUT THE AUTHORS
Pollination Ecology

Revised Nov. 18, 2000.