Background. Chalkbrood disease is caused by the fungus Ascosphaera Apis. The fungus rarely kills infected colonies but can weaken it.
Normally seen in Spring and can just disappear as the colony expands and the bees get busy cleaning house and temperatures increase. Spores can be spread from hive to hive by robbing bees. interchanging equipment. The spores can lay dormant for many years until conditions become right for them.
What does chalkbrood look like?
The larvae become chalk-white and are often covered with cottony filaments
The white coloration may eventually give way to a grey or black, depending on the stage of the fungus
It often appears at the perimeter of the brood nest
Infected or dead larvae may be seen at the hive entrance or the hardened larvae infected referred to as “mummies.” Wil ping on the mesh floor of you’re have during manipulation as they fall out of the comb cells.
What allows the chalkbrood fungus to grow?
Moisture in the hive caused positioning of the hive or by poor ventilation
Poor colony nutrition
Poor genetic resistance
How to guard against or treat Chalkbrood
Re-queen a badly affected hive
Move to a sunnier position
Make sure there is a good ventilation
Replace and old/black comb to reduce spores
Reduce any stress on the hive feed and extra nutrients pollen or good quality pollen substitute.
Inspect the hive for any other problems that may also be causing stress or weakening the colony.