Controlling Varroa Destructor

Integrated Pest Management of Varroa Under Irish Conditions

The future of Varroa control is integrating current treatments with the latest advancements. The idea of an integrated pest management (IPM) may provide a balance between pesticide use and overuse. IPM has the potential to allow beekeepers to keep their operation relatively chemical free and also the power to prolong the life of existing pesticides such as Bayvarol. IPM relies on multiple control methods to pest management.

If a single pesticide is being used to control the pest, there is an excellent opportunity for resistance to develop. The role of IPM is not to eliminate chemical use, but to reduce the amount and the frequency of pesticide application. The Varroa problem is a perfect candidate for IPM.

On completion of the literature review the following were the objectives for May 2003 to December 2003.

  • To carry out a simple Bayvarol resistance test on colonies throughout Ireland
  • To examine the efficacy of different biological methods of Varroa control under Irish conditions. These methods included hive modifications, drone brood trapping, Apiguard and organic acid treatments.

Resistance monitoring is essential in protecting bees from Varroa. The USDA-ARS developed a 'user friendly' screen tool to detect miticide resistance. The assay relies on the comparison of the mite fall after exposure to Bayvarol and the total mite fall after washing.

To monitor resistance on a nationwide scale, Beekeeping Associations were contacted and a number of beekeepers from each region offered to carry out the test on 6-12 colonies per apiary. Sample jars were prepared and sent to cooperating beekeepers, in addition to details of the procedure and a data sheet, which each beekeeper was required to complete.

Beekeepers are presently carrying out this test, as it is advisable to carry it out after the honey has been taken off and prior to Autumn treatment. Results are being returned but are not yet analysed.

Hive modification involved using a variety of floor boards and monitoring mite population using natural mite fall. A test was also carried out to compare the efficacy of Bayvarol, Apiguard and organic acids (formic and oxalic).

The aspirations of the study for the remainder of this year is to finish collecting the data from the present experiments and then analyse it statistically.

In 2004, it is hoped to determine how these control methods (floor variation, drone brood trapping, Apiguard and organic acids) can be used in concert as a means of controlling Varroa and compare their efficacy with Bayvarol. Selection of treatments to be included in the integrated pest management will depend on the results obtained from the present study.

Mary Coffey