BCBC would like to thank
Dr. Zachary Huang, Associate Professor of Entomology, Michigan State University for allowing us to republish his honeybee photos and photo descriptions here. Please visit his site at Beetography.com
Special thanks also to
Dr. David Tarpy, Assistant Professor of Entomology at NCSU for allowing us to republish information on bee pests and treatments. You can visit his site here. |
Cause(s):
The fungus, Ascophera apis
Symptoms:
--- Hardened, white or black "mummies" that resemble the consistency of chalk
--- Mummies can be located in capped or uncapped brood cells, or they may litter the bottom board or on the ground directly outside the front entrance of a hive
Treatment:
--- There are no chemotherapies for chalkbrood. Requeening may be beneficial.
 Chalkbrood, whereby the larvae becomes mouldy with white hyphae (vegetative body of fungi), then hardened to be similar to pieces of white chalk (hence the name). Caused by a fungus (Ascosphaera apis), this disease is mostly considered a "stress" disease, only occuring in weak, or in otherwise stressed colonies (pesticide kill, not enough workers, sudden cold spell in spring etc). The spores are ubiquitous but can only germinate in larvae when the core brood temperature is 2-3 degrees below normal (35 C or 95 F). There is no chemical treatment. Photo by Prof. M.V. Smith, University of Guelph.
 Chalkbrood mummies removed from cells. The two on the top are producing spores, while the three below are at a slightly earlier stage. Photo by Prof. M.V. Smith, University of Guelph.
 Chalkbrood mummies removed from cells. The mummies in the top row are producing many spores, which make the mummie totally black. This stage is now contagious. The mummies in the bottom row are nto producing spores yet and if workers remove them now, the reinfection cycle is broken. Photo by Prof. M.V. Smith, University of Guelph.
|
|
