A survey of managed honey bee colony losses in the Republic of South Africa - 2009 to 2011
Christian W W Pirk, Hannelie Human, Robin M Crewe and Dennis vanEngelsdorp
This study reports honey bee, Apis mellifera L., colony losses that occurred in South Africa over two consecutive years. The total losses were 29.6% (95% CI: 22.8-37.5) in 2009-2010 and 46.2% (95% CI: 37.3-55.0) in 2010-2011. Furthermore, the study shows that the capensis worker social parasite, a problem unique to southern Africa, is the main perceived cause, and could explain the significant differences in the number of losses between beekeepers using the subspecies A. m. scutellata and those using the subspecies A. m. capensis. In contrast to previous studies in North America and Europe, we find a significant negative effect of migratory beekeeping practices on the extent of colony losses. Migratory beekeepers lost on average more colonies (35.5% (95% CI 29.7-47.2)) than did stationary beekeepers (17.2% (95% CI 11.2-22.3)). This was especially pronounced when the beekeepers were migrating for the pollination of apples/cherries, eucalyptus, onions and/or sunflowers. The major beekeeper-perceived causes of mortality were small hive beetles, varroa mites, absconding (non-reproductive swarming), and chalkbrood disease. Those listing chalkbrood disease lost significantly fewer colonies than those who did not list chalkbrood. The exact mechanism for this difference is unknown, and may be related to other beekeeping practices that correlate with finding chalkbrood infections – namely more intensive inspection and management.
honey bee, migratory, mortality, South Africa, colony losses