It is time that the industry spread the truth about amitraz.
Eric Mussen
Entomology Extension
University of California
Davis, CA 95616
Discussions with beekeepers
lead me to believe that many of
them think that amitraz is an
effective chemical for controlling
tracheal mites. This idea may have
originated when another, no longer
available, plastic strip called
Miticur®, was registered for
tracheal mite control. The active
ingredient in that strip was
amitraz.
If you remember the history
of that strip, it was supposed to
knock back tracheal mite
infestations. However, one or more
large beekeeping operations lost
very large portions of their
operations when the strips failed
to control the mites. The
beekeepers sued the chemical
company for the losses and the
strips were removed from the
market.
A thorough reading of many
papers dealing with control of
tracheal mites with amitraz
(Ovasyn®, Mitac®, and Taktic®)
reveals that very few studies
resulted in good control, if the
amitraz was introduced as a
contact treatment. Many authors
had no luck reducing infestations,
unless the amitraz was used as an
aerosol spray or as a burning
“fume strip.”
Therefore, beekeepers who
have been relying on amitraz to
control their tracheal mite
infestations have not been getting
the results that they desire.
There was a time when amitraz did
control Varroa mites effectively,
but continued use of amitraz for
tracheal mite control (?) led to
selection for resistance to
amitraz in Varroa mites,
simultaneously to the selection
for resistance to fluvalinate.
So, this winter, it appears
that something prompted a resurgence
of tracheal mite outbreaks
in some beekeeping operations.
Treatments with amitraz made
little difference and the colonies
collapsed. It is time that the
industry spread the truth about
amitraz and tracheal mites:
contact applications of amitraz
(and its miniscule fumigant
action) do not control tracheal
mites.
Sincerely,
Eric Mussen
Entomology Extension
University of California
Davis, CA 95616
Phone: (530) 752-0472
FAX: (530) 752-1537
Email:
ecmussen@ucdavis.edu
URL:entomology.ucdavis.edu/faculty/mussen