This disease of honeybees is the most common brood disease found in most areas. Caused by the fungus Ascosphaera apis. Chalkbrood is most common in colonies which are stressed by factors such as humid weather, low colony population, American foulbrood, or mite infestation, poor nutrition, and poor hive management. Picture

Treatment is very limited, there are no medications. Best treatment consists of dealing with stress factors that the colony is dealing with.

Cleaning behavior of the workers is maybe only second or third to good ventilation and hive population, to resist chalkbrood.

With weather extremes (cold clustering and heat fanning), the brood may be left unattended, especially when nurse bee numbers become insufficient to attend to duties. Most often the first larvae affected are those that may be unattended regularly around the edges of the brood where the brood temperature may not be consistent.



1.    Destroy chalkbrood and American foulbrood contaminated combs.

2.    Regular requeening.

3.    Add bees to strengthen hives.

4.    Good hive management.

5.    Provide extra good ventilation to remove humidity and minimize temperature extremes, this to will strengthen hives.