Using powdered sugar to control varroa mites in honeybee colonies

Using powdered sugar can provide safe, efficient non-chemical method of reducing varroa mite levels within honeybee colonies.  It also provides a reliable indication of mite levels within a colony. 

 

The technique was first developed in 2000 by Dr. Kamran Fakhimzadeh, Finland.

 

 

How does it work?

There are three possible explanations for the high efficiency of powdered sugar dusting. These are:

  1. Mites use their ambulacrum to grip onto their host.  When the bees are dusted with powdered sugar it could make it more difficult for the ambulacrum to grip the host.
  2. Powdered sugar stimulates the bees grooming behaviour.  Observation has shown that when European bees are dusted with powdered sugar they begin to groom themselves, they persist at this grooming for extended periods of time. 
  3. The third explanation is that the powdered sugar on the mites body stimulates it to release from its host to groom itself. 

 

How do I treat with powdered sugar?

  • Very fine powdered sugar should be used.  I use organic granulated sugar blended in a food processor until it becomes a very fine dust (I prefer not to use icing sugar because of the anti-caking agents it contains). 
  • To prevent caking of the powdered sugar I put a small amount of dry rice inside the shaker.
  • After carrying out any inspection of the colony, before putting the hive back together, is the time to apply treatment. 
  • The aim is to cover all bees in the colony with a fine covering of sugar.  Sugar can either be applied from the top and brushed between the frames or frames can be removed and dusted individually. 
  • Using a mesh floor with the insert in place will allow you to count the mite drop.
  • Treatment should be re-applied regularly (every 7-10 days) if the mite drop is high. 
  • Treatment can be applied at any time of year with no danger of contaminating honey. 

        

For more detailed information on sugar dusting (the 'Dowda Method) to control varroa mite please have a look at the following documents. 

Using inert dusts to detect and assess varroa infestations in honey bee colonies.pdf 

 

Effectiveness of sugar dusting to knock down Varroa destructor from adult honey bees.pdf 

 

Powdered_sugar_dusting_in_bee_colonies_as_varroa_control_updated_9_09_09l.pdf