did not find this surprising: Varroa
mites are the number one (and likely
numbers two and three and maybe
four) cause of colony mortality
in our books. It is tricky however,
to demonstrate the causality link
in the field, even more so when
dealing with a social organism
made off tens of thousands of
smaller organisms. Working with
real-life conditions in the field also
means having to make adjustments,
for example, recognizing that
“autumn” and Mother Nature
don’t really care what month it is,
and that the period of time when
honey bees rear winter bees and
brood area contracts really occurs
over a moving period that varies
considerably by region. September
in Florida looks very different,
weather-wise, than September
in Maine. So our next step is to
add some of those factors in our
modeling efforts.
In addition, as many of us remember,
last year was an anomalous year
for floods, wildfires, hurricanes,
severe heat and drought. There
is no doubt that extreme climatic
conditions challenged honey bees
and beekeepers alike. Also, many
of the Varroa mite treatments
can only be applied during a
narrow temperature window and
any temperatures outside of that
window voids the efficacy of the
product or creates dangerous
conditions for the bees. So those
factors might have affected the loss
observed this winter. Finally, we
also think we are still on the cusp
of getting beekeepers to monitor
frequently (monthly) and treat by
need rather than prophylactically
or by the calendar. This are still
misconceptions and barriers
to adoption for Varroa mites’
treatments, especially by
backyard beekeepers.
You can read the full report on our
website, beeinformed.org, but we
want to take this opportunity to
explain the survey and the results.
Before BIP started recording losses,
there were no other numbers to
compare what “normal” losses
are for beekeepers and what is
considered excessive.
The Bee Informed Partnership
reports total loss, which is
a weighted average of all
operational losses for the U.S.
population. Total loss treats each
colony the same. More simply
stated total loss is, “One colony
one vote.” This means that the total
loss rate is more representative of
commercial beekeeper loss as they
manage a large majority of the
colonies in the survey. That is why
we are reporting total loss for the
whole population as well as for
each types of operation (backyard,
sideline, commercial) so you can
tell how operations of various
size fared over the three seasons.
The total loss is a population
Queen with deformed wings. Deformed Wing virus is one such diseases vectored by
Varroa mites. Varroa mites are arguably the largest driver of colony loss in the U.S.
Messaging and methods to manage Varroa mite populations have been increasing
over the past few years. Photo courtesy of the Bee Informed Partnership, Inc.
IN YOUR ORCHARD
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A L M O N D F A C T S
