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United States Department of Agriculture

Agricultural Research Service

Research Project: Managing and Conserving Diverse Bee Pollinators for Sustainable Crop Production and Wildland Preservation

Location: Pollinating Insect-biology, Management, Systematics Research

Title: Colony collapse disorder (CCD) and bee age impact honey bee pathophysiology

Author
item Vanengelsdorp, Dennis
item Traynor, Kirsten
item Andree, Michael
item Lichtenberg, Elinor
item Chen, Yanping - Judy
item Saegerman, Claude
item Cox-foster, Diana

Submitted to: PLoS Pathogens
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary: Honey bee (Apis mellifera) colonies continue to experience high annual losses that remain poorly explained. Numerous interacting factors have been linked to colony declines. Defining symptoms in bees that are linked with unusual colony losses may permit bee keepers and others to determine the health of colonies and predict colony loss. In this study we examined the specific pathologies associated with honey bees collected from colonies suffering from Colony Collapse Disorder (CCD) and compared these with bees collected from apparently healthy colonies. We identified a set of physical characteristics that occurred at different rates in CCD diagnosed colonies prior to their collapse and also asked if these were seen in healthy bees of different ages. Comparing the two sets of characteristics, we determined a subset of pathologies that reliably predict CCD status rather than bee age and that may serve as biomarkers for colony health, allowing bee keepers to predict colony health prior to collapse. In addition, these pathologies suggest that CCD bees are experiencing disrupted excretory physiology. Our identification of these symptoms is an important first step in understanding the physiological pathways that underlie CCD and factors impacting bee health.

Technical Abstract: Honey bee (Apis mellifera) colonies continue to experience high annual losses that remain poorly explained. Numerous interacting factors have been linked to colony declines. Understanding the pathways linking dysfunction with symptoms is an important step in understanding the mechanisms of disease. In this study we examined the specific pathologies associated with honey bees collected from colonies suffering from Colony Collapse Disorder (CCD) and compared these with bees collected from apparently healthy colonies. We identified a set of physical characteristics that occurred at different rates in CCD diagnosed colonies prior to their collapse: rectum distension, Malpighian tubule iridescence, fecal matter consistency, rectal enteroliths (hard concretions), and venom sac color. The multiple differences in rectum symptomology in bees from CCD apiaries and colonies suggest effected bees had trouble regulating water. To ensure that pathologies we found associated with CCD were indeed pathologies and not due to normal changes in physical appearances that occur as an adult bee ages (CCD colonies are assumed to be composed mostly of young bees), we documented the changes in bees of different ages taken from healthy colonies. We found that young bees had much greater incidences of white nodules then older cohorts. Prevalent in newly-emerged bees, these white nodules or cellular encapsulations indicate an active immune response. Comparing the two sets of characteristics, we determined a subset of pathologies that reliably predict CCD status rather than bee age (fecal matter consistency, rectal distension size, rectal enteroliths and Malpighian tubule iridescence) and that may serve as biomarkers for colony health. In addition, these pathologies suggest that CCD bees are experiencing disrupted excretory physiology. Our identification of these symptoms is an important first step in understanding the physiological pathways that underlie CCD and factors impacting bee health.

Last Modified: 07/23/2017
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