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United States Department of Agriculture

Agricultural Research Service

Research Project: IMPROVE NUTRITION FOR HONEY BEE COLONIES TO STIMULATE POPULATION GROWTH, INCREASE QUEEN QUALITY, AND REDUCE THE IMPACT OF VARROA MITES

Location: Honey Bee Research

Title: The Critical Transition Temperature (CTT) of Chalkbrood Fungi Ascosphaera apis and Ascosphaera aggregata, and its Significance for Disease Incidence

Authors
item Yoder, Jay -
item Heydinger, Derrick -
item Hedges, Brian -
item Sammataro, Diana
item Degrandi-Hoffman, Gloria

Submitted to: CRC Press
Publication Type: Book / Chapter
Publication Acceptance Date: May 30, 2011
Publication Date: January 2, 2012
Citation: Yoder, J.A., Heydinger, D.J., Hedges, B.Z., Sammataro, D., Hoffman, G.D. 2012. The critical transition temperature (CTT) of chalkbrood fungi Ascosphaera apis and Ascosphaera aggregata, and its significance for disease incidence. In: Sammataro, D. and Yoder, J., editors. Honey Bee Colony Health: Challenges and Sustainable Solutions. Boca Raton, FL. CRC Press. p. 131-134.

Interpretive Summary: Predisposing conditions incite chalkbrood disease (Ascosphaera apis) in honey bee colonies either by cooling or warming brood and correspond to an abundance of mummies where temperatures fluctuate widely. This Chapter describes a novel technique for estimating the temperature where the incidence of chalkbrood is the highest, which may vary according to species and different colonies. In the laboratory, growth rates for pure fungal isolates of A. apis were determined by measureing the spread of the myucelium in a Petri dish at different temperatures. Graphical anlaysis shows a temperature where a rapid increase in growth rate occurs, defined as critical transition temperature (CTT). Of interest is CTT of A. apis matches the temperature where chalkbrood symptoms are seen in a bee colony. Thus, determination of CTT of the fungus can be an effective tool for gauging the onset and offset of a fungal disease.

Technical Abstract: Predisposing conditions incite chalkbrood disease (Ascosphaera apis) in honey bee colonies either by cooling or warming brood and correspond to an abundance of mummies where temperatures fluctuate widely. This Chapter describes a novel technique for estimating the temperature where the incidence of chalkbrood is the highest, which may vary according to species and different colonies. In the laboratory, growth rates for pure fungal isolates of A. apis were determined by measuring the spread of the mycelium in a Petri dish at different temperatures. Graphical analysis shows a temperature where a rapid increase in growth rate occurs, defined as critical transition temperature (CTT). Of interest is CTT of A. apis matches the temperatue where chalkbrood symptoms are seen in a bee colony. Thus, determination of CTT of the fungus can be an effective tool for gauging the onset and offset of a fungal disease.

Last Modified: 8/29/2014
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