Bee line memebers:

My definition to robust varroa management is an integrated mite
management system. In ontario we have been using annually a
combination of several methods for management of varroa and
tracheal mites. These methods include:
1) requeening colonies every 2 years with tracheal mite-resistant
hygienic bee stock (1/2 of the operation every year).
2) spring treatment of formic acid in mite-away pad (a single
application formic acid pad was developed and used  in Ontario
since 1996-1997).
3) use of 1-2 drone brood to trap mites in the summer or early fall
if needed.
4) fall treatment with Apistan.

Our research results for evaluating the efficacy of applying this
system showed that:
1) the use of tracheal mite-resistant- hygienic bees slows
the mite development in bee colonies. In case of tracheal mites, the
population will build  very slowly and it will take more than 2 years
to reach a damaging level.  Hygienic bees which are able to remove
>75% of freeze killed pupae are able to reduce the varroa population
by 30%.
2) the use of a single application of mite-away formic acid pad in the
spring is good for a full year for tracheal mite control and good to
kill varroa in the spring without the need to use Apistan treatment
in the spring.
3) Using this system has helped beekeepers in Ontario to achieve the
following:
         a. Reduction of the annual colony mortality from 25-40% to
             less than 10%.
         b. No sign of varroa developing resistance to Apistan which
            has been used in Ontario for 8 years.  We tested varroa
            mites to resistance to Apistan. Results showed that
            Apistan is effective and kills >95% of varroa mites.
        c. No Apistan residues in honey samples. We are in the
            process of testing Apistan residues in the wax.
        d. Beekeepers diversified their management and activities. We
            have a group of queen producers of Buckfast, Carniolian,
           Ontario bees how are involved in the breeding program
           for mite resistance. These beekeepers make their income
           from selling queens. They sell more than 15,000 queens/year
           and 6,000 nuclei/year.
       e. The total number of bee colonies is increasing for the last
           2 years.
       f. Honey production per colony has been increased by 10-20%.

Regarding the cost of this IPM, If you add the annual cost of colony
loss (killed by mites) and replacement of these colonies, 2 times
treatments with Apistan, loss of production. This program is
economically viable and sustainable. This system is far more robust
than relying on the same miticide (Apistan or Coumaphos) year after
year. This system maintains healthy producing colonies year after
year, too.

Cheers,

Medhat Nasr
Medhat Nasr, Ph.D.
Research Scientist,
Ontario Beekeepers' Association
Dept. Environmental Biology
University of Guelph
Guelph, Ontario, Canada
N1G 2W1
Tel: (519) 824-4120
Fax:(519)837-0442
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