Chalkbrood is caused by the fungus Ascosphaera apis and affects the brood. Spores of Ascosphera apis are transmitted through the food. Chalkbrood disease occurs worldwide, especially during the colony’s growth in spring, when there are not enough adult bees present in the hive to keep the rapidly expanding brood warm. The brood located on the edges of the brood frames (generally the drone brood) is most affected because that is where it is the most difficult to control the temperature. Chalkbrood disease is usually not a serious disease; healthy colonies are usually able to overcome it. Following is an overview of the disease, including a description of the symptoms, how to control the disease and how to avoid transmission of the disease.