Managing Varroa Environmental Interventions 

VarroaPest & Diseases
Written By Ken Brown

Each method reduces varroa in the hive. Combining methods can lead to significant reduction in mites and reduced treatments.  

  • Ventilated base: swap solid base for mesh or ventilated base. This can reduce mites by up to 10% in the hive. With a solid base, any mite that drops off a bee can easily get back onto a passing bee. 

  • Drone brood trapping: mites prefer drone cells to worker cells by up to ten times; therefore, putting in a drone frame and removing it just after the cells have been capped will reduce mite levels  

  • Brood break/queen trapping: if you limit brood or even stop it for a while, you are interrupting the lifecycle of the varroa, it requires careful colony management. Any phoretic mites in the hive can then be killed more easily 

  • Resistant queen: a queen can have genes that produce bees that can manage mites. This is a sliding scale from a small difference to being able to survive without any treatments. Beekeepers and researchers around the world are working towards varroa-resistant stock that aren’t susceptible to other diseases or conditions 

  • Heat treatment – bee brood are more tolerant to temperature fluctuations than mites; heating brood frames will kill mites in the cells offering chemical-free treatment  

  • Icing sugar – dusting frames with icing sugar can cause some mite drop; Studies have shown up to 34% phoretic mite drop but results can vary  

  • Smaller cells – natural, smaller cells will cause smaller bees to emerge sooner, disrupting the lifecycle of mites. Proponents of foundationless beekeeping use natural cell size as a key part of treatment-free apiaries  

 

Strong Healthy Hives  

A strong healthy hive is the best defence against varroa-viruses and other diseases and disorders. Hives are weakened by stressors such as overcrowding, damp hiveware, poor nutrition, wasps and diseases making them more susceptible to mites.  

  • Strong healthy hive: bees’ immunity is their best defence; if a hive gets weaker or stressed then it is more susceptible to all diseases. All stressors make a colony susceptible to diseases  

  • Good site: not too close to other hives, not too windy, close to forage  

  • Good hiveware: not damp, no old brood comb, entrance reducers when needed, different colours/patterns to reduce drift  

 

Further information: 

 

Ken Brown
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Managing Varroa A Holistic Approach 
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American Foulbrood (AFB): What Every New Zealand Beekeeper Must Know