CHALKBROOD - Ascosphaera apis

Symptoms and cause

Chalkbrood will probably be seen in most colonies at some time but at varying degrees of severity. It is caused by the fungal pathogen Ascosphaera apis. Spores of the fungus enter the developing larva through the cuticle or orally with contaminated food. These spores germinate and the hyphae of the fungus invade the cells, killing the larva (usually after it has been capped over). Initially the dead larvae will be covered with a white cotton wool-like growth and may swell to fill the cell taking on its shape. After a time these will dry out and shrink to give the characteristic ‘mummies’ that are chalk-like at first turning to a greyish black colour as the fungal fruiting bodies develop. Worker bees uncap the cells of dead larvae so the mummies will be clearly visible; they will also be removed by the workers and may be seen in high numbers on the floorboard or at the entrance to the hive. In very heavily infected colonies, the workers will not be able to uncap all of the affected cells and if a comb is shaken the mummies may be heard rattling in the cells.

SpreadEach chalkbrood mummy produces millions of spores that will adhere to cells and adult bees. It is these spores that are the infective stage of the fungus and may remain viable for up to 15 years. The spores can be spread from hive to hive by drifting bees, or by the beekeeper on equipment and frames moved between colonies.

Treatment and control
A good, strong healthy colony will usually be able to tolerate chalkbrood and it is not usually a serious disease. However, in smaller colonies or those under stress (for example suffering heavy varroa infestations,or death caused to pesticides, ot sudden freezing temperatures during spring time, or lack of worker bees) chalkbrood can be a problem. The best method for keeping chalkbrood to a minimum is the maintenance good strong stocks of bees, although in particularly bad cases the problem may be solved by re-queening with a young and vigorous queen from a chalkbrood-free colony. Choice of apiary site is also important and you should avoid damp sites.

Treatment with Aloevera Products by spaying the bees, or by injecting on to the frames, with the appropriate solution is very effective for chalkbrood elimination.

Our proceedure for population increase, thus secuing very strong healthy colonies, is the best way in preventing the appearanc of chalkbrrod.

(See also POPULATION INCREASE in our blog)

Mixing Aloe Vera products with the syrup is not recommended. It is both waist of time and money.

For information and applications please contact
Athens - Greece
Phone: +30.210.9823241 / + 30.6944-710993
e-mail: info@bees-aloevera.com

No comments: