41st Annual Meeting of the Society for Invertebrate Pathology
and 9th International Conference on Bacillus thuringiensis

In North America, populations of the honey bee Apis mellifera have been in decline since the introduction of the varroa mite, Varroa destructor, in the 1980's. Parasitization by varroa mites still is a major factor underlying most colony losses, most likely through immunosuppression and increased disease instance. However, a new phenomenon was identified in late 2006 that is though to be responsible for large colony losses in affected apiaries: colony collapse disorder (CCD). This condition is identified by a set of unique symptoms: no dead bees in the affected hive or apiary, honey bee brood and food stores are left behind, and secondary pests hesitate to invade affected hive equipment. CCD has continued to have major impact on bee colonies in the United States and significantly add to the already high loss of colonies due to varroa parasitization. In an attempt to determine the cause or causes of CCD, several studies were initiated. Common samples were collected from CCD and non-CCD affected apiaries and shared among various institutions in an attempt to isolate a single causes. No one culprit has yet been found which explain all CCD losses. A longitudinal epidemiological study was also initiated in 2007 that followed individual colonies over time, sampling them repeatedly. This study uncovered several factors which impact bee health but not necessarily how CCD is triggered. This presentation will discuss the approaches being taken to investigate causes of colony losses, and how losses in the United States compares to losses in other countries in terms of magnitude, symptoms and response.