Sustainable Agriculture Literature Review - Boulder County

! !!
"#$%&!'())!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!C+!D.-E.;1$4.2F!
Colony Collapse Disorder
In colony collapse disorder (CCD), honey bee colonies inexplicably lose their workers.
Since the late 1940s, the number of honey producing bee colonies has been decreasing
as shown in Graph 23. 684 Colony collapse disorder has resulted in a loss of 50 to 90
percent of colonies in beekeeping operations across the United States. 685 The syndrome
is mysterious in that the main symptom is simply a low number of adult bees in the hive.
There are no dead bodies in the hive, and although there are often many disease
organisms present, no outward signs of disease, pests, or parasites exist. Numerous
causes of CCD have been proposed, often with little or no supporting data. 686 A study
conducted in 2007 looked at more than 200 variables potentially causing CCD and 61
were found with enough frequency to permit meaningful comparisons between
populations, but no clear cause of CCD was identified. 687
!
Graph 23: Number of Honey Producing Colonies in the U.S. 688 (Data were not
available from 1982 to 1985)
At present, the cause of CCD in U.S. bee colonies remains under investigation, as a
number of realistic and conceivable hypotheses remain plausible. The primary
hypotheses (in no particular order) include: 689
- Traditional bee pests and pathogens
- How the bees were managed (management stress)
- Queen source (poor genetic biodiversity)
- Chemical use in bee colonies to control bee pests / pathogens
- Chemical toxins present in the environment
- Mites (V. destructor) and associated pathogens
- Bee nutritional fitness
- Undiscovered / newly discovered pests and pathogens or increasing
virulence of existing pathogens
- Potential synergistic interactions between two or more of the above
hypotheses.
"'&$"
!,342#.5#6/1!78$.%3/23$1!
9.21$#23$1!:1;.1