Welcome to :
Ulster Beekeepers Association
 
ver1

Home :

 

Varroa Guidance Page

Varroa.

The mite Varroa destructor can infest adult bees and brood. It first infests drone brood but in heavy infestations worker brood is also involved. It is the vector for a number if Virus diseases which do considerable damage.

It cannot be eradicated and, once introduced, will spread to every apiary in Northern Ireland. Without treatment colonies will surely die, but it can be controlled and its numbers reduced to harmless levels.

Control is at its most difficult in the first couple of years, as feral colonies and other untreated colonies, re-infest treated colonies. Healthy colonies rob collapsing colonies and bees from collapsing colonies abscond with the robbing bees. It is most important that all beekeepers treat for Varroa, and at the same time.

The Varroa mite is reddish-brown, oval and has eight legs.. It can be seen on adult bees, in floor debris or on drone brood. Drone brood can be inspected at the pink eye stage by pulling them from their cells with an uncapping fork. Varroa may be dislodged from adult bees by shaking around fifty bees in a jar with a teaspoonful of icing sugar. When the contents are emptied out the bees fly off and the mites can be clearly seen in the sugar. Mites can be dislodged from all the adult bees in a hive by the use of Bayvarol or Apistan strips for 24 hours. The dislodged mites can be collected below a mesh floor. Remember that the majority of mites in a hive are in the brood and so are not dislodged. For treatment with these drugs the strips must remain in the hive for six weeks, to cover two cycles of brood rearing.

Beekeepers MUST follow the manufacturers instructions carefully because if the strips are left on the hives for longer than the recommended period, the mites can become immune to them.

Around 20% of mites are lost through an open mesh floor, so the use of such floors is part of Integrated pest management. This together with the use of the approved drugs, Apistan and Bayvarol, and biotechnical methods such as drone brood trapping can form an overall plan of control which is more effective than drugs alone.

Remember

  • suspected cases of Varroa must be reported to DARD.untreated Varroa will kill ALL your bees
  • but its not all doom and gloom - most of the world has been living with Varroa for years and the demise of feral colonies and bees belonging to "let alone beekeepers" has led to heavier honey yields.

Useful contact for further details: National Bee Unit, www.csl.gov.uk