IN YOUR ORCHARD
30
Almond Facts
JULY | AUGUST 2017
The Bee Box
KAREN RENNICH, Executive Director, Bee Informed Partnership
Colony Loss Survey Results – Still a
Significant Operational Difference
Our annual Bee Informed Partnership (BIP) Colony Loss and Management Survey closed at the end of
April and preliminary loss results are in, and as usual, they are interesting. Additional management
results will be posted to our research website and our dynamic data explorer (see
beeinformed.org/survey) tool in August.
For the 2016-2017 winter season, 4,963 beekeepers in
the United States provided validated survey responses.
Collectively, these beekeepers managed 363,987 colonies
in October 2016, representing about 13% of the country’s
estimated 2.78 million managed honey producing
colonies. An estimated 21.1% of colonies managed in
the United States were lost over the 2016-17 winter. This
represents an improvement of 5.8 percentage points
compared to the previous 2015-16 winter, and is below
the 10-year average total winter loss rate of 28.4% (Figure
1). These winter losses were the lowest recorded since the
survey began in 2006-07.
Beekeepers not only lose colonies in winter (October –
March) but also throughout summer (April – September).
The 2016 summer colony loss rate was 18.1%. When all
the survey results were combined, beekeepers lost 33.2%
of their colonies between April 2016 and March 2017. This
is the second lowest rate of annual colony loss recorded
over the last 7 years.
How do we explain such lower losses this year? In part,
we did see, on average, noticeably lower
Varroa
mite levels
last fall across the country from the National USDA-
APHIS (Animal and Plant Health Inspection Service)
survey than in previous years and this may attribute to
the lower recorded losses this year. A further possibility
of lower
Varroa
pressure (and corresponding lower losses)
was the increase recently of
Varroa
mite products that
appeal to a greater range of management philosophies.
Barriers of adoption for
Varroa
management have
been high, especially among
backyard beekeepers despite
the hard-hitting messages
that have been key to getting
many beekeepers onboard for
monitoring and controlling
the mite population. Perhaps
Figure 1: Summary of total overwintering
colony losses in the United States
across eleven years of conducting
the winter loss survey (yellow bars;
October 1 – April 1) and across seven
years of conducting the summer (April
1 – October 1) and annual loss survey.
Total annual loss values (orange bars)
include total winter and total summer
losses. The acceptable winter loss rate
(grey bars) is the average percentage
of acceptable yearly colony losses
declared by the survey participants in
each year of the survey.
