Chalkbrood is a fungus disease that affects the bee brood. The fungus responsible for its proliferation is the one named Ascosphaera Apis. The fungus develops very well in conditions of low temperature and high level of Carbon Dioxide. They develop even better when the bee family is confronted with a deficiency in proteins.

The fungus develops inside the organism of the infested larvae. It eventually exterminates the larvae after the cell comb is capped. The chalkbrood spreads inside the hive quite rapidly. The dead larvae are sources of infestation since they release Ascosphaera Apis spores. These spores stick on the adult bees and on combs, frames and other hive parts. The spores are quite dangerous since they can live and infest for more than three years.

The disease can be spread throughout the apiary by drifting and robbing bees. The swarms can also move the spores from here to there thus infecting new areas. The beekeepers might also spread the disease when they are doing specific beekeeping activities like moving frames and combs from one hive into another. They can also infect a healthy colony with contaminated beekeeping tools.

Although not as dangerous as other brood diseases chalkbrood still has to be identified and measures have to be taken against it especially in spring. The beekeepers have to carefully examine and inspect the brood combs and the debris on the bottom of the hive. It is better to remove the bees from the frames so as to detect any kind of abnormality. The mummified larvae can be observed and removed.


The infested larvae become chalky after dead. They are white in color and swell so as to fill the cell comb. After a while they get tinnier and in the end they look like mummified larvae. They can be white, gray and even black. The black larvae point out that fungal reproduction is about to take place. The worker bees destroy the caps of the cell containing infested dead larvae. Because of this it is not very difficult to spot the chalky mummified larvae. Most of times, they have a pattern similar to that of a hexagon. The worker bees clean the comb cells from the infested individuals either by throwing them on the hive floor or at the hive entrance. The mummified larva are scattered in the brood combs and in case of severe infection their number is quite high.

The outburst of the disease occurs at the end of spring or at the beginning of summer when in most bee families the brood is higher in number than the adult honey bees. This disproportion prevents the adult bees from keeping a proper temperature and ventilation inside the hive. The diagnosis can be done easily by carefully examining the bee brood.

Prevention and treatment

Most bee colonies suffer from chalkbrood at least once in their life. The spores of the fungus responsible for the disease might exist in the hive without causing too much damage if the bee family is a strong one. Weak colonies on the other hand may seriously affected by the chalkbrood fungus, which is quite powerful during the first spring days. Bee families that die should be closely examined and their honey house should be sealed so as to prevent honey robbing and spread of spores and other agents causing bee diseases. Colonies that are severely infested with Chalkbrood should be re-queened. Fumigation with acetic acid is considered to have a certain effect upon the Chalkbrood causative agents. However, in certain countries it is recommended to destroy comb that are severely infested.

For the time being there is no medication that can be used in order to cure a colony from Chalkbrood. Thus, prevention is advisable and the best solution to the problem. Hygiene is extremely important and therefore all hive should be in perfect condition and the beekeeping tool should be sterilized every once in a while. The brood should be inspected carefully especially in spring and autumn. The old combs in hive should be replaced on a regular basis and they have to be inspected before being moved from one hive to another. Proper ventilation and a sufficient number of bees should be assured to all hives within an apiary. It is also important to take measures against honey robbing and drifting since through these actions the bees spread various diseases including Chalkbrood.

Honey bee disease > Acarine mites > Acute bee paralysis virus > American Foulbrood > Black Queen Cell Virus > Bee louse> Chalkbrood > Chilled Brood > Chronic Bee Paralysis Virus > Cloudy wing virus > Colony Collapse Disorder > Deformed Wing Virus > Bee Dysentery > European Foulbrood > Israelii acute paralysis virus > Kashmir Bee Virus > Nosema > Sacbrood virus > Bee septicemia > Stonebrood > Varroa Mite >

Copyright ©